Between the Poles

Challenges of subsurface digital twins

The subsurface is composed up man made infrastructure; utility, transportation, and other infrastructure and the natural environment comprised of geology and geotechnical properties of the subsurface. A comprehensive subsurface digital twin requires a digital twin of underground infrastructure and a geology digital twin.

Digital twins of the underground infrastructure; utilities, communications, and transportation networks and other infrastructure, of cities, regions and nations have become a priority for many jurisdictions around the world. Over the past decade the emphasis has been on above-ground models, primarily because of the availability of technologies for efficiently capturing high accuracy location data for above ground infrastructure. However, many jurisdictions are recognizing the critical importance of below ground infrastructure and are integrating subsurface infrastructure into their digital twins.

Geological information, such 3D models of geological and geotechnical properties, and borehole databases, comprise an information product that has not yet reached its anticipated level of usage. Geological information has the potential to be useful in a wide range of broad use cases such as city planning, infrastructure construction projects, geohazard identification, environmental impact assessment and the development of water supply facilities, but to date this has not become standard best practice in these application areas. However, there is growing awareness of the importance of subsurface geology (in general but also to the technology used to detect and locate underground infrastructure) and it is expected that in the near future geology digital twins will be recognized as a foundation digital twin equally important to infrastructure digital twins.

Subsurface infrastructure digital twins

Digital models of underground infrastructure is characterized by important distinguishing features that differentiate them from above ground digital models and that need to be taken into account when maintaining and using models of underground infrastructure. These fall into the general categories of fitness for purpose, data quality, and accessibility.

Many cities, for example, Rotterdam, Helsinki, Pilsen, Athens, Rostock, Berlin and London to name a few, regions, such as Flanders, and nations such as the Netherlands, Estonia, Singapore, and the UK are developing 3D geometric models as a basis for digital twins. 3D models of above-ground infrastructure include buildings, transportation networks, parks, and other infrastructure typically captured in 2D or 3D imagery from overflights or in 2D GIS maps. But for a number of reasons underground infrastructure is often neglected, even though it is recognized that water and wastewater, energy (gas, electric power, and district heating), and communications (fibre and copper) networks provide the life blood of the city.

There is now a consensus that modeling a city requires not only information about buildings and transportation networks, but also about the utilities and communications networks. Utility and communications network operators maintain extensive records of their assets, including the location of their assets and operating, inspection, and maintenance data. For years they have used monitoring, control and simulation software for tracking and modeling demand, network energy, water, and gas flows, voltage, and pressure and other features of the modern utility networks. Utilities are expanding this capacity and moving in the direction of digital twins that can represent the entire utility system.  Ultimately this will enable them to support digital twin use cases that extend beyond utility asset management and network simulation to incorporate models of the entire utility network including demand and the supply chain. Digital replicas of energy infrastructure  makes it possible to undertake energy network sizing and routing process analytics to help understand and appraise loads and design optimum energy networks based on actual demand, consumer services and evolving technical solutions. In the UK electricity and gas networks operators have launched a National Energy Systems Map (NESM), a proof-of-concept project that brings together network data from all of Britain’s electricity and gas network operators into a digital, whole-energy system map covering Great Britain. The objective of the pilot project is to give customers information about energy network assets, where those assets are located as well as who owns them and is intended to provide the basis for a digital twin of the UK's energy network.

5G is increasingly recognized as an essential national utility. Knowing the location of all infrastructure is critical to understanding where fiber optic cables and 5G antennae intersect with the people and places that need them. This presents a major challenge because many telcos do not have current, comprehensive data on overground and underground assets in an integrated, easily accessible and shareable format. Operators need comprehensive, accurate and current location-based information on underground fiber-optic networks in relation to all the critical services that depend on them.  This will require integrating live data from all assets in the field with the demand for services from customers.

Challenges of subsurface infrastructure

There is a fundamental difference in what jurisdictions are able to do with representations of above and below ground infrastructure. Above ground, whatever can be photographed or scanned in the public space; from the street, from an airplane or drone, or from a satellite, in 2D or 3D, is generally unrestricted in application.  It is necessary to remove recognizable people and vehicles for privacy reasons and there may be national security restrictions, but in general this data can be used without restriction to create an open, publicly available digital model or digital twin.  The accuracy of the above-ground data in digital twins is generally high - for digitally LiDAR scanned data accuracy even reaches the mm level.

Underground the situation is different. First of all, there are restrictions on access to underground infrastructure location data.  In many jurisdictions some or all of the underground infrastructure in the public right-of-way is privately owned.  Where cities own water and sewer services, this data may be open and publicly accessible, but electric power, gas, and telecom are often privately owned and private ownership imposes restrictions on public access to this data. For example, the City of Rotterdam has decided that a key requirement of its digital twin is open access to the public. But for underground infrastructure the city has had to recognize restrictions on access. About 2/3 of the underground utility data is open and accessible, but there are access restrictions on the remaining 1/3 because these represent privately owned facilities.

Another major challenge in most jurisdictions is data quality. Utility network documentation and records are not collected or maintained consistently, the level of accuracy varies, data is often out of date and for abandoned infrastructure frequently missing. Over the past decades electric, gas, water, and telecom utilities have poured millions into digitalizing the graphic design/work management and GIS/records management processes. But the decades-old as-builting process remains marred by manual paper-based processes that results in low data quality and which has ramifications for the construction industry and for society in general. One of reasons for low data quality of network documentation is that utility business models provide no direct incentives to improve their data at the scale required for a full solution. This is a complicated problem that may require government involvement through regulation, changes in industry best practices and new technologies. Jurisdictions such as Colorado, Montana, and Singapore have implemented regulations focused on improving data quality. New technologies such as reality capture with LiDAR or a handheld phone together with RTK and other technologies for accurate positioning and mobile+cloud solutions for capturing and sharing data in the field are enabling real-time high accuracy data capture during construction.

Return-on-investment studies of improving information about underground infrastructure

Return on investment (ROI) studies of the benefits of improving the mapping underground infrastructure on highway construction projects conducted since the late 1990s have consistently revealed a large return-on-investment. A U.S. Department of Transportation sponsored survey conducted by Purdue University in 1999 of quantifiable and qualitative savings estimated a total of US$4.62 in avoided costs for every US$1.00 spent on accurately locating underground infrastructure. Although qualitative savings (for example, avoided impacts on nearby homes and businesses) were not directly measurable, the researchers made the case that those savings were significant, and many times more valuable than the quantifiable savings. In 2007, the Pennsylvania Department of Transportation commissioned Pennsylvania State University to study the savings on Pennsylvania highway projects and found a return on investment of US$21.00 saved for every US$1.00 spent for SUE when elevating the quality level of subsurface utility information using SUE. This significantly higher return on investment when compared to Purdue study is the result of maturation of process and a consideration of some of the qualitative savings in the Purdue study.

Fitness-for-purpose for subsurface utility models

Straits Times

For underground utilities the Open Geospatial Consortium's MUDDI underground standards project has identified important use cases for underground infrastructure location data including planning, reducing underground utility damage during construction, construction efficiency, asset management, emergency response, and disaster planning. Each use case has specific data requirements. For example, the planning use case may not require survey-grade location accuracy, it may only be necessary to refresh the data once or twice a year, and the level of detail may be low. Fitness-for-purpose for each use case will determine the quality of the data to be fed into the digital twin, the algorithms that model urban processes, the simulations that need to be supported and the analytics and visualization technology that makes the model cognitively easy and accessible to users.

The Netherlands, Helsinki, and Singapore have developed master plans for the subsurface that support multiple use cases. As an example, a number of years ago Singapore recognized the urgency for a map of its underground utilities for a number of purposes; planning, design, construction, ownership and maintenance of underground infrastructure. The Singapore Land Authority (SLA) initiated the Digital Underground project aimed at establishing an accurate, current, and complete map of subsurface utilities in Singapore that could be used for multiple use cases.

Priority use cases for subsurface utility models

However, the priority use cases for subsurface digital models in most jurisdictions are reducing underground utility damage during construction and construction efficiency. The simple reasons for this are economic. The cost of damage to underground infrastructure during construction amounts to tens of billions of dollars every year, injuries and fatalities of workers and the public, and delays and budget overruns on civil engineering construction projects. For this use case data accuracy, currency and completeness are essential requirements. Another issue specific to underground infrastructure is integration. In general each utility and telecom has a different data model, vocabulary, symbology, base map, standards for layout, and data protection guidelines. To integrate data from multiple organizations requires harmonizing these features in a common standard agreeable to all data providers.

Thus current geometric models of underground infrastructure will require important changes to enable them to be used as a basis for a subsurface digital twin. Digital twins are living models and need to reflect the changes in real time of the underlying assets. The key is to integrate live data from all subsurface assets and ensure that the geospatial systems modelling these networks share a common standard and are a ‘living document’ constantly drawing on current data and intelligence from the field. Databases of real time, high precision underground infrastructure data compliant with an agreed on standard are required. This requirement and new technology advances are driving fundamental changes to how data about underground infrastructure is captured and maintained.

Real time ground deformation monitoring from satellites to reduce risk of damage to utilities and pipelines

Several years ago I blogged previously about an application that used Sentinel-1 radar interferometry to monitor ground displacements with millimetre precision to look for subsidence which might be evidence of a leak in a municipal water system. Now access to data and processing algorithms are available to developers to create workflows to monitor ground deformation to reduce the risk of damage to underground Infrastructure including utilities, oil, gas and water transmission pipelines and associated industrial plants.

Ground movement represents a significant risk to linear structures such as utility, pipeline, and transportation networks as well as to large scale industrial and commercial structures.  Traditionally ground deformation is monitored by fixed high accuracy GNSS stations located at intervals and by periodic surveys along alignments.  Both of these are expensive and are limited by geospatial and temporal gaps. Satellites such as Sentinel-1 that use radar to image the earth are capable of radar interferometry (INSAR) which allows ground deformations on the order of cm and even mm to be detected.  The revisit times for these satellites are on the order of days and the radar antennas on these satellites allow very large areas to be monitored for deformations.  For example, Sentinel-1 is capable of detecting deformations of a few mm over an area of 42,500 km² with a 12 day revisit time. Furthermore INSAR data is available stretching back to the mid 1990's making it possible to monitor historical ground movement over quite long time periods.

UP42 provides the infrastructure of an enterprise software development and deployment platform enabling developers to create scale-able workflows using satellite imagery and customized algorithms. In a recent UP42 webinar (53 minutes in), Shawn Melamed and Sarah Thompson of CATALYST (PCI Geomatics) showed how innovative INSAR technology has made it possible to cost effectively continuously monitor ground deformation along thousands of km of  a linear structure such as a utility, pipeline, or transportation network.  The data can be sourced from any of the satellites capable of INSAR including Sentinel-1 (free) and TerraSAR-X (commercial).  An example is provided in the talk of the development of a UP42 workflow for detecting uneven land subsidence in California resulting from agricultural withdrawals of water from an aquifer that potentially could damage a power plant located in the area.  The code to perform this analysis is available as the Ground Displacement Block on the UP42 marketplace.

 

 

Advanced geophysical remote sensing rapidly captures high resolution 3D data about subsurface geology

Uncertain knowledge about what lies under the surface is a major cause of delays and budget overruns on construction projects.  It is well known that not knowing the location of utilities and other infrastructure is a major cause of delays, but unforeseen ground conditions; soil conditions, ground water and underlying geology, is also a major cause of large budget overruns on construction projects, especially for projects involving deep excavation and construction below the seabed.  Advanced remote sensing, 3D digital ground modeling and visualization technologies are changing dramatically how we capture, analyze, visualize and share information about the subsurface.

Background 

Every construction project devotes considerable effort to discovering subsurface geotechnical conditions and structural geological setting.  The traditional approach involves boreholes, CPT and test pits. Regardless of the process, all geotechnical acquisition results in point data.  This data is used by the engineering consultant for a single project and rarely shared. 

In the Netherlands an attempt is being made to address the problem by the Key Registry for the Subsurface (BRO) which came into force in January, 2018. The BRO registry ultimately will record 26 geotechnical data types. In the UK the Dig to Share project, supported by Atkins, the British Geological Survey (BGS) and Morgan Sindall, is also attempting to address this problem. Its aim is to develop a fully digital workflow, which is accessible to the whole industry, to upload and access data from a web-based system.

The traditional approach to data collection about the structural geological setting involves shallow seismic reflection, seismic refraction, and legacy resistivity methods.  These methods provide information about the different layers underlying a site though not always as accurate as required. Typically, this type of data is low resolution, and will usually not be useful in defining key sub-bottom variations such as the transition between compacted sands and rock, vertical features or variations in rock strengths across a site. In addition, legacy qualitative methods rarely provide the quality and accuracy to generate reliable and useful high-resolution models of the variations in each stratum across a site.

Three-dimensional geological modeling has developed dramatically over the past 30 years from contouring and gridding techniques using mainframe computers through to PC based geological modeling software. These tools were developed for certain industries such as mining and oil and gas and deal with very specific geological scenarios and data types. Many geological survey organizations worldwide have started to implement varying software systems and methodologies to facilitate a migration, from a 2D paper-based survey to a 3D digital service provider of geoscientific information. Rapid advances in gaming technology has enabled a renaissance in ground modelling and particularly in 3D visualizations.

Advanced remote sensing technologies

Another approach relies on remote sensing technologies that are designed to acquire large volumes of high-resolution data about the structural geology over a large area, quickly.  These advanced geophysical methods are digital and allow for determination of thickness and depth of geological layers as well as layer and intra-layer information from the one sensor. Shot intervals are better than one per second make it possible to collect large volumes of high-resolution data in a short period of time. The objective is to understand subsurface complexities in detail at a site which makes it possible to target boreholes to elucidate geological anomalies.  I had the opportunity to talk to Jason Errey, Director OEMG Global, about one of these advanced technologies.

High resolution resistivity technology

One such method is Aquares, an advanced resistivity technology which enables the capture of high resolution quantitative and qualitative information about the strata under a site. Quantitative data includes depth and thicknesses of sub-bottom structures. Qualitative data includes type of sediment; sand, silt or clay and rock characteristics such as fresh or weathered. High resolution combined quantitative and qualitative data is extremely useful for successful planning construction activities including, dredging, trenching, under bores, tunneling, or piling. With this information project planners and engineers have a complete picture of the existing subsurface environment. This allows designs to take into account subsurface structures such as weathered and unweathered rock outcrops or buried river valleys to considerably reduced dredging and construction costs.

Modern digital ground modelling practice is essential for planning and asset management. The results of high resolution Aquares surveys can be combined with other data in an Integrated Digital Ground Model (IDGM) via the MyGeoTwin product. Data is acquired for the IDGM in a staged manner and stored in a data lake for use in future projects.

Vertical cross section of Sydney Harbour

Sydney Harbour Metro tunnel

An example of where the Aquares high resolution resistivity technology was deployed is the Metro tunnel under the Sydney harbour in Australia.  In late 2016, Sydney Metro commissioned an Aquares advanced geophysical survey. The Aquares survey was undertaken in two stages over two nights. On the first night a high-resolution survey targeted the top 15 metres below seabed.  On the second night the survey extended this to a further 40 metres below seabed. A week after acquisition, a four-dimensional model covering the top 40 metres below seabed comprising one million data points was delivered to the Sydney Metro Authority.  When compared to the legacy below seabed information, the new geophysical information showed substantial differences in the rock levels in addition to previously undetected remnants of a river channel following a geological fault line.

Vertical geological section of Sydney. Aquares resistivity survey data has been inserted into the project IDGM allowing vertical sections to be exported to GIS/CAD, Google Earth, Augmented Reality and holographics.

The new technology is also more efficient.  For the initial design for the tunnel created in 2015 two years was spent conducting and analyzing multiple legacy geotechnical and geophysical surveys, costing millions of dollars. Due to site complexities, these early surveys failed to define the correct rock level and the associated geological risks. The Aquares survey was completed in 2 nights, processed in a week and combined with all other available data in a 4D ground model a week after that, at a fraction of the cost.

Buenaventura dredging

The Port Authority in Buenaventura needed to undertake maintenance and capital dredging along a 10 km section of a 180 m wide channel leading to the port. Based on limited seismic results that were unable to identify intra-layer variability and five boreholes, dredging contractors assumed approximately 30% sediment and 70% hard rock and estimated an average dredge cost of $17.6 per cubic metre.

The results of a more advanced Aquares geophysical survey method provided crucial information about the level of the sediment-rock interface and the differentiation of harder and softer rock types.   The survey found that the channel bottom was composed of 70% soft sediments, 25% rock and only 5% hard rock. As a result, cost estimates were lowered to $7.9 per cubic metre. For the dredge volumes on this particular 10 km section of the access channel, the cost savings were estimated at $34 million.

Conclusion

Modern digital ground modelling practice is essential for planning and asset management. Advanced remote sensing, digital data acquisition and management tools now available reduce the risk of unforeseen geological conditions delaying and significantly increasing the cost of major construction projects. Advanced digital geophysics provides a reliable source of 3D data that can be integrated into an integrated ground model to provide asset owners with a digital tool to manage and control risks relating to subsurface ground conditions.

Burgeoning market for shareable subsurface geotechnical information

Unforeseen ground conditions are a major cause of delays in construction projects.  This year, at Bentley Systems’ Year in Infrastructure Conference, Roger Chandler, Director of Geotechnical Information Management, announced OpenGround, a collection of applications for collecting, sharing, visualizing, analyzing, and accessing geotechnical information about the ground. OpenGround is a cloud-based SaaS application with a web API, which in its short life has already amassed a database of over 500 thousand boreholes.

Every construction project devotes considerable effort to discovering subsurface geotechnical conditions, but this data is often used by the engineering consultant for a sinle project and rarely shared.  In the Netherlands an attempt is being made to address the problem by the Key Registry for the Subsurface (BRO) which came into force in January, 2018. The BRO registry ultimately will record 26 geotechnical data types.

In the UK the Dig to Share project, supported by Atkins, the British Geological Survey (BGS) and Morgan Sindall, is also attempting to address this problem. Its aim is to develop a fully digital workflow, which is accessible to the whole industry, to upload and access data from a web-based system.

I had the opportunity to chat with Roger to understand better the business drivers for OpenGround and the growing market for software for capturing, sharing and analyzing geotechnical information about the ground.

Amey Consulting

Roger explained that the market consists primarily of engineering consulting and construction contractors, although there are also utilities, primarily water companies, who routinely conduct borehole surveys prior to installing new infrastructure. The information captured from boreholes includes location, information about each layer or stratum including a description, standard soil type classification, and the geological formation to which it belongs together with in-situ and laboratory test data. Currently, this data is captured typically by pen and paper, but mobile apps are more efficient in capturing this information and is being rapidly adopted. Mobile apps are already being used by 20% of all users and the speed of adoption is increasing.

There are two important drivers that are behind the rapid expansion of this market. The first is sharing geotechnical information among consulting engineers and contractors on construction projects. Typically survey and borehole information is used by engineering consultants when designing a new facility, but this information is rarely shared with construction contractors. OpenGround is designed to enable everyone involved in a construction project to have secure access to this important information.

Secondly, over time storing the information captured from boreholes from various projects and keeping it alive and available for future projects is a benefit for regional bodies creating digital cities and may be a source of competitive advantage for a construction or engineering company doing repeat work in the same geographic areas. This may explain why some companies may be less than enthusiastic about sharing their private geotechnical information on open sites.

The borehole information that is captured by a company and stored using OpenGround remains private. But since it is stored in the cloud it can be made available to everyone within the company and can also be shared with other participants on a construction project. This enables consulting engineering companies to share geotechnical information with other players on a project. In the context of Bentley projects geotechnics is critical for many construction projects, but especially for civil engineering projects. OpenGround is designed to integrate with other products such as PLAXIS, OpenRoads, OpenRail, STAAD.foundation, and others.

OpenGround represents an important step forward in IT tools enabling the sharing of information about the ground. This is a commercial service, and the rapid growth in this market is evidence that companies are recognizing significant value in capturing and sharing geotechnical information both within a company and with other players on a construction project.

New OpenGround product for sharing underground geotechnical data achieves over 500,000 boreholes

Unforeseen ground conditions are a major cause of delays in construction projects.  This year at the Year in Infrastructure event Bentley announced OpenGround a collection of applications for collecting, sharing, visualizing, analyzing, and accessing geotechnical information about the underground. It has already amassed a database of over 500 thousand boreholes. 

Reports from the National Economic Development Office (NEDO) found that 50% of commercial buildings and 37% of industrial buildings experienced delay due to unforeseen ground conditions.  There are two aspects to the problems associated with the subsurface.  One is geotechnics, soil, ground water, and geology conditions.  The other is the location of underground infrastructure, utilities, telecommunications and other cables and pipes.

Every construction project devotes considerable effort to discovering subsurface geotechnical conditions, but this data is used for the current project and rarely shared.  In the Netherlands an attempt is being made to address the problem by the Key Registry for the Subsurface (BRO) which came into force in January, 2018. The BRO registry ultimately will record 26 data types.  On 1 January 2018,it become mandatory to report the first three data types, geotechnical surveys (CPT), groundwater monitoring wells and soil drilling sample profiles. On 26 June 2018, this data became publicly available via the Dutch open data portal PDOK.

In the UK the Dig to Share project, supported by Atkins, British Geological Survey (BGS) and Morgan Sindall, is addressing this problem. Its aim is to develop a fully digital workflow, which is accessible to the whole industry, to upload and access data from the BGS web-based system. This will be developed on top of the existing system hosted and maintained by BGS. 

Last year Bentley announced the acquisition of Keynetix, a UK-based provider of cloud-based software for capturing, visualizing, modeling, and sharing geotechnical data. This added to Bentley's products for the subsurface including borehole report management (gINT and HoleBASE) and geotechnical analysis applications (PLAXIS 3D and SoilVision) with which Bentley plans to enable a digital twin of the underground.

This year at the Year in Infrastructure 2019 event in Singapore Roger Chandler, Director of Product Management, GeoTechnical Information Management, announced a new product OpenGround (based on Keynetix.cloud).  OpenGround is a cloud-based SaaS application with a web API that supports real-time logging of subsurface geotechnical data and enables sharing this data over the web.  In the very short time since OpenGround became available it has already amassed a database of over 500 thousand boreholes. 

Improving and sharing geospatial information about the subsurface in England

NEDO estimates that about 50% of time over-runs on commercial building projects are caused by unforeseen ground conditions.* There are two aspects to the problems associated with the subsurface.  One is geotechnics, soil, ground water, and geology conditions.  The other is the location of underground infrastructure, utilities, telecommunications and other cables and pipes. There are growing government, private sector and standards initiatives in both of these areas in the U.K. to improve the information and sharing of information about the subsurface.

Social driver: Public safety

Public safety is an important social driver for improving knowledge about the underground.  I remember attending a Pipeline Industries Guild (PIG) conference in Birmingham, U.K. in 2005 where the focus of the entire event was to motivate the pipeline operators industry in England to voluntarily participate in a call-before-you-dig centre that would reduce the risk of damage to underground infrastructure during excavation.  There had been a near major disaster in Birmingham (Hunton Hill) when a gas company crew had attempted what was supposed to be a routine tap into a gas main to connect a new customer.  Three drill bits later, the crew knocked off.  Fortunately an ESSO contractor just happened to pass by and recognized that the gas crew had been attempting to tap into a high pressure fuel line.  At the conference the section of pipe with dimple caused by the gas crew was shown.  A number of experts described the the extent of the disaster that would have followed if the crew had tapped into the line.  The 2003 gas explosion in Belgium would have paled by comparison.  In just the last month in the Americas, there has been an explosion in downtown San Francisco, another one in Durham, North Carolina, one in downtown Sao Paulo, and an evacuation of a neighbourhood in Calgary, Canada when a 6" gas main was ruptured during excavation.

Economic driver: construction productivity

UK construction productivity compared to other sectors

The major problem facing the construction industry in advanced economies is productivity which has plateaued or even declined over the past 40 years. With the growth of private investment in infrastructure, improved productivity has become urgent. McKinsey has made the case that BIM and geospatial are key technologies in transforming construction.  The U.K. has been a leader in the digitalization of the construction industry, mandating that from 2016 all public construction in the U.K. must use a BIM Level 2 process.  The subsurface has been for the most part ignored in the application of digital technology to construction, but there are signs now that this is changing in the U.K., as people recognize the drag on construction projects and the broader national economy that this represents.  Improving the reliability of and sharing location information about the underground can be seen as 'low hanging fruit' in the quest to improve construction productivity. 

Sharing subsurface geotechnical information

One of the problems is that every construction project involves considerable effort to discover subsurface geotechnical conditions and the location of underground infrastructure in the area to be excavated, but a large proportion of the data generated by the UK ground engineering industry is used for one project and not shared.  In the Netherlands the problem is being addressed by the Key Registry for the Subsurface (BRO) which came into force in January, 2018. The BRO registry consists of 26 data types, which will become mandatory in installments over five years and all of which include location. On 1 January 2018,it become mandatory to report the first three data types, geotechnical surveys (CPT), groundwater monitoring wells and soil drilling sample profiles. On 26 June 2018, this data became publicly available via the Dutch open data portal PDOK.

In the UK the Dig to Share project, supported by Atkins, British Geological Survey (BGS) and Morgan Sindall, is addressing this problem. Its aim is to develop a fully digital workflow, which is accessible to the whole industry, to upload and access data from the BGS web-based system. This will be developed on top of the existing system hosted and maintained by BGS. 

I should add that in the domain of geotechnics Keynetix is a UK-based provider of cloud-based software for capturing, visualizing, modeling, and sharing of geotechnical data. Bentley Systems has just announced the acquisition of Keynetix which adds to Bentley's products for the subsurface including borehole report management (gINT) and geotechnical analysis applications (PLAXIS and SoilVision) with which Bentley is targeting enabling a digital twin of the underground. 

Sharing information about the location of underground infrastructure

The Geospatial Commission has just announced its intention to create an Underground Assets Register.  The intention is to show where electricity and telecom cables, and gas and water pipes are buried to help prevent both accidents and disruption to the economy.  The project will start with £3.9 million pilot projects split between London and the North East.

Pipes and cables beneath a road crossing in North East England - Thanks to Holger Kessler for sharing.

Related to this is the North East Underground Infrastructure Hub (NEUIH) , the Ordnance Survey's and Northumbrian Water's project to create a ‘Common Infrastructure Map’ in Newcastle.  The current phase of the initiative is called ‘Sunderland sand box’ and implements a dataset that contains almost full water, gas, electricity and a great deal of telco data for the city of Sunderland.

Collecting underground utility damage statistics

The U.K. has not had access to good statistics on underground utility strikes similar to the Common Ground Alliance in North America.  Since 2014 the Utility Strike Avoidance Group (USAG) has begun collecting statistics on underground utility damage. USAG currently operates on a voluntary basis with no direct funding other than the support offered by member organizations.  Its 2015/2016 report includes over 2700 utility strikes across the UK during 2015 & 16 from 32 participants.  For comparison in the U.S. there were 316,422 incidents of damage to underground infrastructure reported to the Common Ground Alliance in 2017.  According to the Japan Construction Industry Association (Edson Enohi personal communication), in all of Japan in 2016 there were 134 incidents.

One-call centre for England

England does not have legislation mandating a one-call centre as just about every state and province in North America does.  This puts the onus on excavators to track down and contact utilities and others who may have infrastructure in the area of the planned excavation.  To fill the gap a private company LinesearchbeforeUdig (LSBUD) offers something similar to a North American one-call centre. I had the opportunity to chat with Richard Broome, Managing Director of LSBUD.  LSBUD offers a voluntary free to use service which anyone planning excavation can use to check for underground utility assets that LSBUD's 75 members (network operators) have in the area of the planned excavation.

The way this works has some similarities with a North American one-call centre.  The excavator provides details of the planned excavation to an online system.  The system immediately responds with a list of LSBUD members that have assets near where the excavation is planned.  Subsequently each member sends plans of their infrastructure assets in the area of the planned excavation.

LSBUD is owned by Fisher German LLP and PelicanCorp, an Australian company that runs one-call centres in Indiana, Kentucky, Alberta, British Columbia, New Zealand, Australia, Ireland, Singapore in addition to the UK. The assets that LSBUD's member manage include hundreds of thousands of kilometers of underground and overhead electricity, gas, high pressure fuel, water and fibre optic pipes and cables.  LSBUD is supported by its members which include all fuel transmission companies, 60-70% of electric power network operators, and some water and telecom operators in England. The benefits that the members derive from LSBUD are improved safety and reduced utility damage costs. The public also benefits from fewer outages.  The LSBUD service processes over 2.5 million inquiries per annum.

There are risks of sharing information for both commercial (competitive) or security purposes. To manage this balance, the Member always controls who accesses their data. Members always controls who accesses their data. Users can get very high level information about a Member’s network through the LSBUD oce call process, but members are in full control of the access rights to their detailed information. They also have a live view of those requesting and receiving their information together with a detailed audit trail.

Much of the liability is on the contractor to locate the assets on site. In terms of the accuracy/ validity of the data, the asset owner carries that themselves with relevant disclaimers. The asset owner determines both the Area of Interest (AOI) on the service, as well as any guidance/literature/disclaimers that are sent with their responses.

Coordinating street works

One area that would directly benefit from shared location information about the subsurface is street works. In 2004 the UK Parliament passed the Traffic Management Act, which gave highway authorities greater power to manage traffic disruption caused by 2.5 million roadworks that take place in England each year.  In particular it requires excavators to apply for a permit (as Bern has done) for road work providing information about the location and timing of the proposed road work.  Late last year the Department for Transport announced an investment of £10 million in Street Manager, a digital planning service that will generate real time data about street construction.  It will be free for technology companies and app developers to use. This will allow services like Waze (whose vision is to eliminate traffic congestion) and startups to build app that help motorists avoid congestion caused by road construction.

The Traffic Management Act also enables local councils to charge a fee for permitting road work.  One way of using this power is referred to as lane rental.  Pilots have been carried out in several location in England and have been found to reduce congestion by half on busy roads.  For this to be used effectively requires accurate locate information about underground utilities and communications infrastructure.

Standard relating to the underground

A process to update the 2014 Publicly Available Specification (PAS) 128, has just been initiated.  PAS 128, developed under the auspices of the British Standards Institution (BSI) and sponsored by the Institution of Civil Engineers (ICE) and others, is one of the few that reflects the advances in underground detection technology - hardware and software - that have occurred in the last few years.  That it is now being updated suggests that PAS128 will continue to stay current with the underground detection technology curve.

The Open Geospatial Consortium MUDDI initiative to develop a standard for sharing information about the subsurface, including both geotechnics and underground infrastructure, is supported by the Ordnance Survey and includes several U.K. and INSPIRE standards.

Together these government, private sector and standards initiatives reflect the accelerating recognition in the UK of the importance of sharing information about subsurface geotechnics and infrastructure for public safety and construction productivity.

Reference

* N.M.H. Alhalaby and I.L.Whyte, The impact of ground risks in construction on project finance in Risk and reliability in ground engineering, Edited by B.O.Skipp, Proceedings of the conference organised by the Institution of Civil Engineers, London, 1993.

"A statistical review of projects revealed that 50% of commercial buildings and 37% of industrial buildings experienced delay due to unforeseen ground conditions. Reports from NEDO state that the most frequent origin of overruns and long delays (greater than 10 weeks) are unforeseen obstacles in the ground."

NEDO Faster building for industry. National Economic Development Office London 1983

NEDO Faster building for commerce. National Economic Development Office London 1988

Role of surveyors in digitally mapping underground utilities

Last week I was invited to speak at the Alberta Land Surveyors Association Annual General Meeting in Banff, Alberta about locating and mapping underground infrastructure. I thought it would be worthwhile to share the talk that I gave where I highlighted opportunities for surveyors.

The subsurface is often ignored.  This is partly a case of out-of-sight is out-of-mind. But it is also the result of broken business processes in the construction industry that place much greater value on physical assets than on what is now being called the digital twin representing the location, behaviour and status of underground assets.  Knowing the location of underground energy infrastructure is critical for national security, for disaster planning and management, for public safety and for economic efficiency. Everyone is aware of at least one disaster resulting from or exacerbated by not knowing where our energy infrastructure is - the recent explosions in San Francisco and Durham NC and the evacuation just last week of a neighbourhood in Calgary when a 6" gas line was hit during an excavation come to mind.

Impact of unknown and inaccurately located subsurface infrastructure and geotechnics

The best documented example I know of the economic impact of not knowing accurately where underground infrastructure is the Sydney Light Rail Extension Project.  This is a $2.1 billion PPP project for 12 km of light rail to be completed by 2019. Prior to awarding the contract for construction the Department of Transport for New South Wales undertook 12 months of work to map 5,000 subsurface utilities along the route. 500 existing subsurface utilities were identified for relocation to make way for the new light rail infrastructure. During construction it was found that the as-built information from utility providers was frequently unreliable including incorrect location and incorrect materials. The second problem was that during construction an additional 400 unknown services were encountered. As anyone in the construction industry will tell you - discovering unknown underground utility infrastructure occurs frequently on construction projects. Both of these caused disruption and delays with construction. In this case ACIL Allen, a respected Australian consulting firm, was asked to estimate what the impact of unknown and inaccurately located utilities was on the project. Their study concluded that if a complete and reliable 3D map of underground infrastructure had been available at the project planning stage, the project could have been completed at least one and a half years sooner, at less cost with a much lower level of risk. While the project apparently remained ‘on time and on budget’, ACIL Allen says that this is only because the risk of delays and additional costs resulting from unidentified underground utilities were included in the contract pricing and schedule.

An example that shows the benefit of knowing where underground utility infrastructure is located is the I-20/I-59 Corridor project in Alabama.  This is a $750 million interchange project in the heart of Birmingham's business district.  For this project the Alabama Department of Transportation (ALDOT) took an unusual approach.  Using potholing, scanning with ground penetrating radar, professional surveyors and existing as-built records a 3D model of below-ground utilities was created.  When the project was put out to tender each contract each bidder was provided with the 3D model.  ALDOT estimated that it saved $10 million on the project with this approach.  Perhaps more importantly the project remains on schedule and on budget - remarkable for a project of this complexity and magnitude in a dense urban environment.

Setting the context: the construction industry is ripe for digitalization

To put this in context there is massive investment in infrastructure projects around the world as evidenced by the US$ 90 billion Delhi-Mumbai industrial corridor project in India which will affect some 180 million people.  McKinsey estimates that we will need to spend $57 trillion on infrastructure over the next decade or so.  But how infrastructure is financed is changing and this is changing the construction industry.  Governments have less and less money for capital projects.  Since 2003 growing amounts of private capital have been going into infrastructure projects.  In 2016 total private investment in infrastructure projects reached nearly $80 billion.  Unlike government which looks for a social return, private investors such as pension funds, insurance companies, and sovereign wealth funds require a financial return.  This drives a focus on improving productivity. As the automobile manufacturing, financial services, airline and other industries have shown this drives investment in IT technology. 

McKinsey has made the case that construction is ripe for transformation and that digitalization will be a key technological driver.  R&D investment in the construction industry has been among the lowest of any industry, ranking nearly last, at the same level as hunting.  Construction productivity in the world's advanced economies including Germany, Japan, UK, EU, US, and South Korea has been stagnant or declining for the past 40 years, a period during which general industrial productivity has more than doubled.  McKinsey has made the case that digitalization could help raise construction productivity and identified five technologies that it believes will be key for transforming the construction industry.  Two of these are building information modeling (BIM) and geospatial.

BIM+geospatial provides the basic technology for modelling underground infrastructure.  BIM involves a 3D model, associated data, and a collaborative approach to construction. BIM has been or is being mandated for public works in many countries and has also been adopted by many private sector companies.  Furthermore there is growing evidence of the benefits of an integrated BIM + geospatial full lifecycle approach to construction, especially for infrastructure projects.  For example, it has been estimated that applying this approach for the Nagpur Metro project will save over $200 million over the 25 year lifetime of the project.  In Canada EllisDon, who began taking on PPP projects 15 years ago, has made integrated BIM+geospatial a best practice for their PPP projects. 

To drive improved financial returns and attract private capital owners and the construction industry are looking for low hanging fruit. Reducing the risk of unknown and inaccurately mapped underground utilities can dramatically reduce costs and duration for construction projects as the Alabama I-20/I-59 Corridor project has shown. 

Key facts about unreliable and incomplete information about subsurface infrastructure

The Common Ground Alliance (CGA) collects statistics regarding damage to underground infrastructure during construction.  The CGA estimates that there are 400,000 cases of utilities being hit during excavation every year at at average cost of $4000 in direct costs per hit. In the U.S. according to Federal Highway Administration (FHWA) underground utility conflicts and relocations are a major cause of project delays during road construction.  In addition every year there are injuries and deaths attributable to hitting underground utilities. 

In the U.K. research by the University if Birmingham has estimated that the direct cost of a utility strike during construction ranges from £ 300 for water and sewer to £ 2,800 for fiber-optic cables.  More importantly the indirect and social cost, which includes traffic disruption, injuries to workers and the public, and loss of business custom was estimated to be about 30X the direct cost.

Every construction project requires investing time and effort prior to and during excavation to locate underground utilities. Construction bids are routinely inflated by 10-30% to accommodate risk associated with unknown or poorly located underground utilities  In the U.S. this has engendered what is estimated to be a $10 billion per year industry. Every state in the U.S. and most provinces in Canada have a one-call centre and legislation that requires anyone planning to excavate to contact the centre.  Utilities and telecoms are required to send crews to locate and indicate with paint or pin flags the location of their underground infrastructure.  Because they are considered liable for any underground damage, wise construction contractors do not rely solely on this information but increasingly use expensive vacuum and hydro excavation equipment in detecting and exposing underground infrastructure during excavation.  But the information captured by these techniques is rarely shared and the location of underground infrastructure is recaptured over and over again.

Together this represents a considerable drag on the construction industry.  In the U.S. if indirect and social costs are included this represents at least a $50 billion drag on the economy and this does not include insurance costs.  Of this the largest share is borne by the consuming public in the form of service disruption - phone, power, heating and water outages.

Several university studies have estimated the benefit in terms of an ROI of knowing accurately where underground infrastructure is located. One of the most recent by Pennsylvania State University found $21 in cost saving for every dollar invested in improved location information about underground infrastructure.  In the U.S. the Federal Highway Authority (FHWA) cites studies that have shown that the cost of detecting underground utilities prior to construction typically costs less than 0.5 percent of the total project construction cost, saves more than $4 for every $1 spent, and can reduce project delivery time by as much as 20 percent. A study resulting from an underground survey in Milan in preparation for a World Fair there estimated that €16 were saved for every € invested in accurately locating underground infrastructure.

Underground utilities and highway construction

The Alabama I-20/I-59 Corridor project has shown that a 3D map of underground infrastructure can reduce risk and keep highway construction projects on budget and on schedule. As Ron Singh, who was Chief of Surveys at the Oregon DoT, has argued, underground utilities are a huge problem for highway construction projects.  In his view we need to stand the traditional highway construction process on its head.  He explained that this means the traditional approach - survey, design, locate utilities, move utilities, build, and prepare as-builts - needs to be replaced by an approach that relies on a prior 3D model of above and below-ground infrastructure which will provide 85% of the information required about the existing site and situation.  The new process will require a rapid initial survey for sanity checking the information in the 3D model followed by design with knowledge of underground utilities.  This approach would avoid expensive moving of utilities as much as possible and only move utilities that cannot be avoided during design.  During construction underground utilities would be laser-scanned. A post-project 3D survey and laser-scanning would replace paper as-builts.  A side-benefit of this approach is that it would with time build up accurate models of highways which many believe will be essential for the safe operation of autonomous vehicles.

Cost-effectively mapping the underground

The keys to cost-effectively and accurately mapping underground infrastructure are first of all policies and technologies that ensure that the location of new infrastructure going into the ground is captured accurately and cost-effectively,  secondly policies and technologies that require that the location of infrastructure exposed during construction is captures accurately and cost-effectively, and thirdly policies for sharing information about underground infrastructure (essential in the U.S. where this information is restricted under Critical Infrastructure Protection (CIP) regulations).  These goals will require modernized quality standards for underground infrastructure, standards for sharing underground infrastructure location data, and hardware and software advances for cost-effectively and accurately detecting and recording the location of existing underground infrastructure.  There are important opportunities for professional surveyors in capturing accurately and responsibly the location of new and existing infrastructure.  The challenge will be to develop new business practices and adopt new technologies to be able to do this cost-effectively so as not to significantly increase the cost of construction or burden government with major additional mapping costs.

Technology advances in detecting underground infrastructure

A research project by Costain and Bentley investigated using photogrammetry with photos taken by consumer grade smartphones together with professionally surveyed control points. Typically it involves taking 40-60 pictures of exposed infrastructure with a smartphone. This process has been found to result in a 3D model of comparable accuracy to a traditional survey, is much more cost-efficient and once the control points are surveyed is something that anybody can do. Most importantly it enables the capture of accurate underground utility location during construction with little additional cost.

In a similar vein Bentley Systems has experimented with a system that equips excavation equipment with four inexpensive digital cameras that are used to collect images of underground infrastructure encountered during excavation.  The resulting videos and images were then loaded into Bentley ContextCapture software and exposed pipes and cables located with centimeter accuracy by referencing accurately surveyed neighbouring structures such as houses and other buildings.  Again this approach enables the capture of accurate location data about underground infrastructure location during construction with little added cost.

In 2018 two technical advancements in detection were reported that bring the cost-effective mapping of underground infrastructure at the municipal, regional, and national level closer to reality. T2 Utility Engineers, based in Whitby, Ontario commercially use a IDS GeoRadar Stream EM multi-channel ground penetrating radar (GPR) array towed routinely at 10-12 km/hr to capture subsurface data.  In a separate initiative a successful proof of concept has been reported by DGT Associates in Mississauga, Ontario in which data collected by a Siteco rig combining a Faro mobile laser scanner and Sensors and Software GPR arrays collected data simultaneously above and below ground at roadway speeds of 80 to 90 km/hr. In both cases the data was collected in soil conditions that were less than optimum for GPR. Being able to capture data at or near roadway speeds addresses an important obstacle to efficiently creating 3D maps of the underground. In both cases significant time was required to post-process the collected sc 3D models.  However, advances in software are making this process more reliable and faster.

In another interesting development Lux Modus has developed a rig and software running in the cloud that captures 3D location information in "near real-time" as a pipeline is constructed.  The rig includes LiDAR and photo cameras which capture the trench and the pipeline by driving along each section before the trench is filled to record a point cloud and photos.  The point cloud and images are uploaded for cloud processing and within minutes to hours a digital twin of the pipeline can be viewed by anyone with a browser that supports HTML5 including mobile devices.  For example, this makes it possible for QA/QC people to use mixed reality to identify weld points in the office rather than having to go out in the field.

Satellite sensors are also finding application in detecting damage to underground infrastructure.  Planetek has developed an application Network Alert that uses Sentinel-1's radar interferometry to monitor ground subsidence with millimeter precision.  Network Alert alerts water utilities af areas of subsidence which can be symptoms of water leaks.

There are further indications of accelerating research and development initiatives related to underground infrastructure. In the U.S. for the first time the Common Ground Alliance (CGA), which represents the utility locate industry in North America, has just released a Technology Report, which describes the current state of underground detection technology including the latest developments and the gaps which CGA has identified in current hardware and software.

In the UK there have been quite a few research initiatives relating to underground infrastructure. The Mayor of London and the Smart London Infrastructure Network, which is composed of utilities responsible for water, energy, telecommunications and waste management in London, sponsored a challenge with the objective of developing digital technologies to accurately locate underground assets, including pipes, cables and joints, and determine their condition. The goal was to improve safety, and to reduce operational downtime, cost and environmental impact, and disruption. A national 10 year academic research program Mapping the Underworld focussed on remote-sensing for locating sub-surface utilities is completed and been replaced by a follow-on 10 year program Assessing the Underworld. The BIM for the Subsurface (2015-2017) project, funded by Innovate UK, aimed to address issues such as project delays due to unforeseen ground conditions by applying the BIM process directly to ground investigation and subsurface infrastructure design.

Sharing information about the underground

To complement the advances in detection there are several initiatives to develop ways to share information about underground infrastructure that is captured during construction. The City of Chicago has launched a pilot to deploy a platform for collecting data and creating and sharing a 3D map of underground. It is based on new technology developed by University of Illinois at Urbana-Champaign’s Real-Time and Automated Monitoring and Control Lab (RAAMAC) and Chicago start-up CityZenith. During excavation a dozen or more pictures are captured with an inexpensive digital camera. RAAMAC's software uses the photos to create a 3D digital model of the underground infrastructure. These models can be securely shared between the City of Chicago and construction contractors to improve project planning and limiting accidents. The advantage of this approach to data collection is that it does not interfere with construction and does not add any significant cost.

But perhaps the initiative that everyone interested in improving knowledge of the underground should be following is a national program in the Netherlands which is supported by legislation and standards. In 2015 a new law was passed by the States General which created the Basisregistratie Ondergrond (BRO) or Key Registry for the Subsurface.  This database is open and accessible to all citizens of the Netherlands.  This went live in 2018 and requires that if you excavate or drill you have to share your data relating to geotechnics with the BRO registry. In addition if when using the data in the registry you find something is incorrect you are required to report it.

While the BRO registry in the Netherlands relates to subsurface geotechnics, the Geopatial Commission in the Cabinet Office in the U.K. government has just announced an initiative to create a registry of underground infrastructure assets.  The register will show where electricity and telecom cables, and gas and water pipes are buried and is intended to prevent both accidents and disruption to the economy.  The project will start with £3.9 million pilot projects split between London and the North East.

Worldwide initiatives to map underground infrastructure

There are successful examples around the world where municipal and regional governments have helped enable a shared underground utility network database. I have blogged about a few shared databases of utility location data (water, sanitary and storm sewers, electric power, telecommunications, gas, and district heating) I've encountered worldwide over the years: Sunderland UK, Netherlands, France, Chicago, Alabama, Singapore, Sydney, Milan, the KLIC system in the Netherlands, KLIP in Belgium, Penang, Sarajevo, Calgary, Edmonton, Jalisco, UK, Japan, Bahrain, Rio de Janeiro and Sao Paulo, Delhi, Bern, and even an open water network portal in New Zealand. Perhaps the closest to a shared integrated infrastructure database is the one supported by the Integrated Cadastral Information Society (ICIS) in British Columbia which includes geospatial data for property boundaries, utility and communications networks, taxation jurisdictions, conservation districts, and the agricultural land reserve. Most of the shared infrastructure information initiatives I have come across involve government, some result from regulation, others are run by government, still others involve cooperation between government and participating utilities and communications firms, and a few are voluntary industry consortia.

The grandfather of shared underground infrastructure databases is the system developed many years ago for Tokyo. The mainframe-based Road Administration Information Center (ROADIC) system, which was deployed first in Tokyo and then in other major cities in Japan, provides information about the location of underground infrastructure including telecommunications and utilities.

In North America the City of Calgary, Alberta mandated the JUMP (Joint Utility Mapping Project) many years ago. A city by-law requires that anyone placing cables or pipes undergound within city limits provide 2D maps in electronic form showing the location of the infrastructure. Originally in the form of DGN files the maps only show location and type of infrastructure (water, gas, electric power, telecom) and owner. The City of Edmonton, Alberta also has a shared facilities mapping database.

Las Vegas has conducted a pilot for a 1.5 mile corridor of Main Street in old Las Vegas.  Using a variety of reality capture technologies including GIS, survey, design records, test holes, and ground penetrating radar (GPR) a 3D model of above below-ground infrastructure was prepared.  Las Vegas also attempted to ensure that in the future accurate 3D location of new or displaced infrastructure would be captured.  Contractors were required to use open trenching, to survey new and displaced utilities before closing trenches, and to avoid trenchless digging if possible.  Augmented reality was used to visualize above and below-ground infrastructure.

In France a national regulation requiring mapping of subsurface infrastructure titled Decree relating to excavations near underground, overhead or underwater transmission or distribution networks was promulgated on 15 February 2012. It requires mapping all critical underground infrastructure in urban areas by 2019 and in rural areas by 2026. Across France different departmental organizations have taken responsibility for implementing the decree. 

The Urban Redevelopment Authority (URA) of Singapore intends to release a masterplan of Singapore's subsurface infrastructure in 2019.​ It will be released as part of the next national Master Plan for Singapore's development in the medium term. When completed it will provide the first comprehensive 3D map at what lies beneath the surface from utilities a few meters deep to transportation tunnels, deep sewer lines, deep petrochemical storage, deep water reservoirs and even deep ammunition stores.

The North East Underground Infrastructure Hub (NEUIH) is the overall initiative name for an initiative supported by the Ordnance Survey and Northumbrian Water to map underground infrastructure in the North East of England. The first phase of this project was a ‘Common Infrastructure Map’ covering a few small sample areas around Newcastle.  This combined map is the first step towards creating the NEUIH.  The current phase of the OS initiative is called ‘Sunderland sand box’ and implements a dataset that contains almost full water, gas, electricity and a great deal of telco data for the city of Sunderland.

Standards for underground infrastructure

Recently there have been developments that reflect improvements in underground remote sensing technology. Standards for reporting the reliability of the locational information about underground utilities have been in place for decades. In the U.S. the 2003 ASCE 38-02 which has been used for classifying location information about underground infrastructure according to its estimated reliability, is widely seen as being out of date. In Canada the CSA S250 standard released in 2011 specifies absolute precision levels for exposed utilities. In France the 2012 presidential decree defines three explicit levels of cartographic accuracy for underground structures; A - less than 40 centimeters, B - 40 centimeters to 1.5 meters, and C - greater than 1.5 meters.  In the UK the 2014 Publicly Available Specification PAS128, developed under the auspices of the British Standards Institution (BSI) and sponsored by the Institution of Civil Engineers (ICE) and others, not only includes the A,B, C, D quality levels of the U.S. standard, but extends it with explicit precision levels B1 to B4 that reflect the improved capabilities of underground remote sensing technologies such as electromagnetic induction and ground penetrating radar. A process to revise PAS128 to reflect newer technical developments has just been initiated.

For sharing information about underground infrastructure the Open Geospatial Consortium's (OGC) underground information initiative, with the appropriate acronym MUDDI, is intended to provide an open standards-based way to share information about the below ground. The MUDDI project has identified several different broad use cases that the model is intended to support including routine street excavations (EX), emergency response (ER), utility maintenance programs (OM), large scale construction projects (AE), disaster planning and response (DP), and smart cities programs (SC). For each of these, several basic requirements that the model needs to satisfy have been identified. For street excavations the requirement is location of all entities with high horizontal, medium vertical accuracy (2.5D) of underground infrastructure; for large construction projects, detailed 3D geometry of underground infrastructure and detailed 3D geology; for emergency response, interdependencies between different networks; for utility maintenance, network topology and facility location and condition; and for smart cities the ability to monitor and relate streams of data from sensors.

The MUDDI model is intended to build on and be compatible with many existing reference/target models. For infrastructure these include CityGML with Utility Network ADE (Application Domain Extension) , INSPIRE Utility Networks, IMKL (Information model for cable and pipes), BIM-IFC, Land and Infrastructure Conceptual Model (LandInfra), Singapore Underground Geospatial Model, PipelineML, Underground Pipeline Information Management System, CIM (Common Information Model), Multispeak, ESRI Utility Model, and GEOfeature. For geotechnics, the reference/target models are GeoSciML, INSPIRE Geology, GroundwaterML, BGS National Geological Model, EarthResourceML, GeoTOP, SoilEML, IFC Geotechnical Extension, MINnD, and BoreholeIE.

To provide a way for the model to be used by different types of users, the concept of profiles has been introduced. Profiles have been used for other OGC standards and allow for different levels of complexity for different domains and applications. The proposed profiles include asset, excavation, emergency, planning and integration profiles.

National initiatives to map underground infrastructure

In the UK combining above and below-ground information into one national digital twin will allow industry to share business developments and innovation activities.  Project Iceberg is an exploratory project undertaken by the British Geological Survey, Ordnance Survey and the Future Cities Catapult to investigate ways to integrate data and services relating to the underground with other city data. To date two reports Market Research into the Current State of Play and Global Case Studies and Defining the problem space for an integrated data operating system above and below ground have been published and are publicly available.The medium term objective is to take these concepts forward with project partners to develop new digital data demonstrator projects.

In the U.S. to begin to address the challenge of accurately mapping national critical infrastructure the National Academy of Public Administration (NAPA), Arizona State University (ASU), the American Geographical Society (AGS), and the National Academy of Construction (NAC) convened leaders in public administration, infrastructure development, geography, geospatial, and data integration/open data at Arizona State University in Tempe, Arizona.

At Geospatial World Forum 2019 I learned of an initiative in Estonia, one of the most digitalized countries in the world to create a national digital twin of above and below-ground infrastructure.

Wrap-up

In summary unreliable information about the location of underground infrastructure and underground geotechnics costs world economies billions of dollars every year.  Missing or inaccurate information adds risk to every construction project.  In the U.S. locating subsurface infrastructure is a $10 billion per year industry.  The information is rarely shared with the result that this information is recaptured over and over again.  To provide a standard for sharing information about the underground including infrastructure and geotechnics the Open Geospatial Consortium has initiated a standards development effort called MUDDI which is being built on many existing standards.  An important national initiative to share information about the underground has begun in the Netherlands.  The UK government has just initiated the process to create a national registry of underground assets in the U.K.

A number of cities and regions around the world which have already recognized the importance of reliable information about the underground have developed ways of collecting and sharing information about the subsurface.  Recently the awareness about the importance of information about the subsurface has reached the national level.  France has mandated that the location of critical underground infrastructure must be known to within 40 cm.  Recent initiatives in Estonia, Singapore, the U.K. and the U.S. are aimed at creating national digital twins including underground infrastructure.

Professional surveyors could have an important role in capturing accurately the location of new and existing infrastructure.  The challenge will be to develop new business practices and adopt new technologies to enable this to be achieved cost-effectively – in the short term it cannot increase the cost of construction or burden government with significant additional mapping costs. In the long term the benefits include reduced risk for construction contractors which will reduce costs especially insurance. It will also provide significant benefits to owners including government by reducing the cost of infrastructure construction and maintenance.

First international workshop on digitally mapping the underground

At Geospatial World Forum 2019 the first international workshop on digitally mapping the underground Underground mapping for resilient infrastructure: Datafication of the Underground was organized by Rob van de Velde and Paul Janssen of Geonovum.  The objective of the workshop was to discuss the complex challenges relating to underground geotechnics and infrastructure that dense urban habitation and the requirement to optimize the use of earth’s resources.  The workshop combined commercial, academic, and government perspectives on subsurface data requirements including use cases, data providers, procurement, organization and business cases, standardization, legislation, and international cooperation.  It was described by several participants as  a "breakthrough in governmental – business shared vision and action."

I thought it would be worth while to include here the talk that I gave to kick off the discussion and set the context for the following talks by Alexander van Noort, Fugro; Martin Peersmann, Key Registry of the Underground of the Netherlands(BRO); Caroline Groot,Cable and Pipeline Information Centre (KLIC); Bart De Lathouwer, Open Geospatial Consortium (OGC); Tan Boon Khai, Singapore Land Authority; and Paul Janssen, Geonovum. In subsequent articles I plan to cover the material presented in these presentations at the workshop.

The subsurface is often ignored.  This is partly a case of out-of-sight is out-of-mind. But it is also the result of broken business processes in the construction industry that place much greater value on physical assets than on what is now being called the digital twin representing the location, behaviour and status of underground assets.  Knowing the location of underground energy infrastructure is critical for national security, for disaster planning and management, for public safety and for economic efficiency. Everyone is aware of at least one disaster resulting from or exacerbated by not knowing where our energy infrastructure is - the recent explosion in San Francisco in California (2019) and the massive explosion in Belgium (2004) immediately come to mind.  As was discussed in a recent workshop not knowing the geotechnics under alternative right-of-ways for a highway can result in much greater construction costs and unanticipated schedule overruns.

Impact of unknown and inaccurately located subsurface infrastructure and geotechnics

According to McKinsey we need to spend about $57 trillion over the next couple of decades on infrastructure, a considerable proportion of it underground, and the cost of doing this is inflated substantially by not knowing underground conditions.  The best example I know of the economic impact of not knowing accurately where underground infrastructure is the Sydney Light Rail Extension Project.  This is a $2.1 billion PPP project for 12 km of light rail to be completed by 2019. Prior to awarding the contract for construction the Department of Transport for New South Wales undertook 12 months of work to map 5,000 subsurface utilities along the route. 500 existing subsurface utilities were identified for relocation to make way for the new light rail infrastructure. During construction it was found that the as-built information from utility providers was frequently unreliable including incorrect location and incorrect materials. The second problem was that during construction an additional 400 unknown services were encountered. As anyone in the construction industry will tell you - discovering unknown underground utility infrastructure occurs frequently on construction projects. Both of these caused disruption and delays with construction. In this case ACIL Allen, a respected Australian consulting firm, was asked to estimate what the impact of unknown and inaccurately located utilities was on the project. Their study concluded that if a complete and reliable 3D map of underground infrastructure had been available at the project planning stage, the project could have been completed at least one and a half years sooner, at less cost with a much lower level of risk. While the project apparently remained ‘on time and on budget’, ACIL Allen says that this is only because the risk of delays and additional costs resulting from unidentified underground utilities were included in the contract pricing and schedule.

Another example highlighted the risk of nor knowing underground geotechnics before embarking on highway design was reviewed in a workshop organized by Geodan and TNO in Amsterdam a couple of years ago. In the workshop two alternative routes for a new connector highway were assessed based on limited information about the underground geotechnics underlying the routes.  This was based on a historical event in the north of Holland. At the time it was decided to build the route using the shorter right-of-way through farmland rather than the longer route which followed existing road and rail lines. After extensive construction delays and rising costs because of the unforeseen poor soil conditions underlying the route through the countryside, it was ultimately decided to build an elevated roadway at much greater cost to the construction contractor and the regional government.

An example that shows the benefit of knowing where underground utility infrastructure is located is the I-20/I-59 Corridor project in Alabama.  This is a $750 million interchange project in the heart of Birmingham's business district.  For this project the Alabama Department of Transportation (ALDOT) took an unusual approach.  Using potholing, scanning with ground penetrating radar, and existing as-built records a 3D model of below-ground utilities.  When the project was put out to tender each contract each bidder was provided with the 3D model.  ALDOT estimated that it saved $10 million on the project with this approach.  Perhaps more importantly the project remains on schedule and on budget - remarkable for a project of this complexity and magnitude in a dense urban environment.

The Common Ground Alliance collects statistics regarding damage to underground infrastructure during construction.  There were 316,442 cases of utilities being hit during excavation in 2017 at at average cost of $4000 in direct costs per hit. In addition there are injuries and deaths. In the U.S. according to Federal Highway Administration (FHWA) underground utility conflicts and relocations are a major cause of project delays during road construction. Several university studies have estimated the benefit in terms of an ROI of knowing accurately where underground infrastructure is located. One of the most recent by Pennsylvania State University found $21 in cost saving for every dollar invested in improved location information about underground infrastructure.  In the U.S. the Federal Highway Authority (FHWA) cites studies that have shown that the cost of detecting underground utilities prior to construction typically costs less than 0.5 percent of the total project construction cost, saves more than $4 for every $1 spent, and can reduce project delivery time by as much as 20 percent. A study resulting from an underground survey in Milan in preparation for a World Fair there estimated that €16 were saved for every € invested in accurately locating underground infrastructure.

In the U.K. research by the University if Birmingham has estimated that the direct cost of a utility strike during construction ranges from £ 300 for water and sewer to £ 2,800 for fiber-optic cables.  More importantly the indirect and social cost, which includes traffic disruption, injuries to workers and the public, and loss of business custom was estimated to be about 30X the direct cost.

Every construction project requires investing time and effort including expensive vacuum and hydro excavation equipment in detecting and exposing underground infrastructure prior to and during excavation. Construction bids are routinely inflated by 10-30% to accommodate risk associated with unknown or poorly located underground utilities  In the U.S. this has engendered what is estimated to be a $10 billion per year industry. But this information is rarely shared and the location of underground infrastructure is captured over and over again.

Together this represents a considerable drag on the construction industry.  In the U.S. if indirect and social costs are included this represents at least a $50 billion drag on the economy.

Worldwide initiatives to share location of underground infrastructure

There are successful examples around the world where municipal and regional governments have helped enable a shared underground utility network database. I have blogged about a few shared databases of utility location data (water, sanitary and storm sewers, electric power, telecommunications, gas, and district heating) I've encountered worldwide over the years: Sunderland UK, Netherlands, France, Chicago, Alabama, Sydney, Milan, the KLIC system in the Netherlands, KLIP in Belgium, Penang, Sarajevo, Calgary, Edmonton, Jalisco, UK, Japan, Bahrain, Rio de Janeiro and Sao Paulo, Delhi, an open water network portal in New Zealand, the Integrated Cadastral Information Society (ICIS) in British Columbia, and the North East Underground Infrastructure Hub (NEUIH) in the UK.  The grandfather of shared underground infrastructure databases is the mainframe-based Road Administration Information Center (ROADIC) system, which was deployed first in Tokyo and then in 11 other major cities in Japan, and which provides information about the location of underground infrastructure including telecommunications and utilities.

A remarkable project of the City of Sao Paulo, one of the World's largest megacities, is GeoCONVIAS.  This  integrates data from 20 to 30 utilities operating in the city of Sao Paulo, . The most important objectives of the GeoConVIAS project are to organize underground infrastructure to prevent accidents during excavation, reduce inconvenience to the public, and reduce the costs of maintaining underground infrastructure. The utilities in Sao Paulo are not asked to provide detailed information about their underground facilities, just "a simple line" showing the location of their facilities.  We were fortunate to have Marcos Romano of GeoCONVIAS present at the GWF2019 session in Amsterdam.

A major step forward in mapping underground infrastructure was a pilot project carried out using ground penetrating radar (GPR) on the site of the Expo Milano 2015 event in Milan. The total project area is about 230,000 square meters. All underground infrastructure including electric power, water, sewers, gas, district heating, street lighting, and telecommunication, were mapped using ground penetrating radar (GPR) which was compared to historical records. An analysis revealed an estimated return on investment is about €16 for every euro invested in improving the reliability information of underground infrastructure.

In France a national regulation requiring mapping of subsurface infrastructure titled Decree relating to excavations near underground, overhead or underwater transmission or distribution networks was promulgated on 15 February 2012. It requires mapping  all critical underground infrastructure in urban areas by 2019 and in rural areas by 2026.

In 2016 the City of Chicago launched a pilot to deploy a platform for collecting data and creating and sharing a 3D map of underground. It is based on new technology developed by University of Illinois at Urbana-Champaign’s Real-Time and Automated Monitoring and Control Lab (RAAMAC) and Chicago start-up CityZenith. During excavation a dozen or more pictures are captured with an inexpensive digital camera. RAAMAC's software uses the photos to create a 3D digital model of the underground infrastructure. These models can be securely shared between the City of Chicago and construction contractors to improve project planning and limiting accidents. The advantage of this approach to data collection is that it does not interfere with construction and does not add any significant cost.

But perhaps the initiative that everyone interested in improving knowledge of the underground should be following is a national program in the Netherlands which is supported by legislation and standards. In 2015 a new law was passed by the States General which created the Basisregistratie Ondergrond (BRO) or Key Registry for the Subsurface.  This database is open and accessible to all citizens of the Netherlands. The law mandates that beginning in 2018 if you excavate or drill you have to share your data relating to geotechnics with the BRO registry. In addition if when using the data in the registry you find something is incorrect you are required to report it.

Standards for sharing information about the underground

The open Open Geospatial Consortium's (OGC) underground information initiative, with the appropriate acronym MUDDI, is intended to provide an open standards-based way to share information about the below ground. The MUDDI project has identified several different broad use cases that the model is intended to support including routine street excavations (EX), emergency response (ER), utility maintenance programs (OM), large scale construction projects (AE), disaster planning and response (DP), and smart cities programs (SC). For each of these, several basic requirements that the model needs to satisfy have been identified. For street excavations the requirement is location of all entities with high horizontal, medium vertical accuracy (2.5D) of underground infrastructure; for large construction projects, detailed 3D geometry of underground infrastructure and detailed 3D geology; for emergency response, interdependencies between different networks; for utility maintenance, network topology and facility location and condition; and for smart cities the ability to monitor and relate streams of data from sensors.

The MUDDI model is intended to build on and be compatible with many existing reference/target models. For infrastructure these include CityGML with Utility Network ADE (Application Domain Extension) , INSPIRE Utility Networks, IMKL (Information model for cable and pipes), BIM-IFC, Land and Infrastructure Conceptual Model (LandInfra), Singapore Underground Geospatial Model, PipelineML, Underground Pipeline Information Management System, CIM (Common Information Model), Multispeak, ESRI Utility Model, and GEOfeature. For geotechnics, the reference/target models are GeoSciML, INSPIRE Geology, GroundwaterML, BGS National Geological Model, EarthResourceML, GeoTOP, SoilEML, IFC Geotechnical Extension, MINnD, and BoreholeIE.

To provide a way for the model to be used by different types of users, the concept of profiles has been introduced. Profiles have been used for other OGC standards and allow for different levels of complexity for different domains and applications. The proposed profiles include asset, excavation, emergency, planning and integration profiles.

National initiatives to map underground infrastructure

The Urban Redevelopment Authority (URA) of Singapore intends to release a masterplan of Singapore's subsurface infrastructure in 2019.​ It will be released as part of the next national Master Plan for Singapore's development in the medium term. When completed it will provide the first comprehensive 3D map at what lies beneath the surface from utilities a few meters deep to transportation tunnels, deep sewer lines, deep petrochemical storage, deep water reservoirs and even deep ammunition stores.

In the UK combining above and below-ground information into one national digital twin will allow industry to share business developments and innovation activities.  Project Iceberg is an exploratory project undertaken by the British Geological Survey, Ordnance Survey and the Future Cities Catapult to investigate ways to integrate data and services relating to the underground with other city data. To date two reports Market Research into the Current State of Play and Global Case Studies and Defining the problem space for an integrated data operating system above and below ground have been published and are publicly available.The medium term objective is to take these concepts forward with project partners to develop new digital data demonstrator projects.

In the U.S. to begin to address the challenge of accurately mapping national critical infrastructure the National Academy of Public Administration (NAPA), Arizona State University (ASU), the American Geographical Society (AGS), and the National Academy of Construction (NAC) convened leaders in public administration, infrastructure development, geography, geospatial, and data integration/open data at Arizona State University in Tempe, Arizona.

At GWF2019 I learned of an initiative in Estonia, one of the most digitalized countries in the world to create a national digital twin of above and below-ground infrastructure.

Wrap-up

In summary unreliable information about the location of underground infrastructure and underground geotechnics costs world economies billions of dollars every year.  Missing or inaccurate information adds risk to every construction project.  In the U.S. locating subsurface infrastructure is a $10 billion per year industry.  The information is rarely shared with the result that this information is recaptured over and over again.  To provide a standard for sharing information about the underground including infrastructure and geotechnics the Open Geospatial Consortium has initiated a standards development effort called MUDDI which is being built on many existing standards.  An important national initiative to share information about the underground has begun in the Netherlands.  Starting in 2018, information about subsurface geotechnics captured through drilling or excavation must be uploaded to the Key Registry of the Underground or BRO which is openly available to the public. 

A number of cities and regions around the world which have already recognized the importance of reliable information about the underground have developed ways of collecting and sharing information about the subsurface.  Recently the awareness about the importance of information about the subsurface has reached the national level.  France has mandated that the location of critical underground infrastructure must be known to within 40 cm.  Recent initiatives in Estonia, Singapore, the U.K. and the U.S. are aimed at creating national digital twins including underground infrastructure.

Progress toward a unified model for underground infrastructure and geology

TNO, Geological Survey of the Netherlands

Information about the location, condition and interdependencies of the infrastructure and geology below our feet is poor or lacking.  Even though information about what is below ground is revealed by every excavation, it is rarely shared.  At the December Open Geospatial Consortium (OGC) Energy Summit at EPRI in Charlotte, Josh Lieberman of the OGC presented an overview of the progress of OGC's underground information initiative, with the appropriate acronym MUDDI, which is intended to provide an open standards-based way to share information about the below ground.

Unreliable information about what is underground including infrastructure and supporting structures and their interdependencies; soil, sediment, fill, and interstitial water and air; and physical, biological, and chemical properties leads to risk of injury to workers and the public and produces a significant drag on the construction sector.   Josh quoted an estimate from the the Institution of Civil Engineers (ICE) that about 50% of cost and time over-runs on civil engineering projects are caused by 'unforeseen ground conditions. If we are going to optimize where and how we build, we need much better information about what is below ground at the planning stage. To give a practical example close to home, in the middle of the Ottawa LRT project, a huge sink hole which unexpectedly appeared in the middle of a major street in Ottawa was blamed for a significant delay in the project as well as serious traffic disruptions.

There are a number of data models for different types of underground infrastructure and geology which raises the question; why do we need another ? The answer is twofold; in the context of a smart city we need to be able visualize and analyze all this information together, not just one network at a time.  Secondly MUDDI is not an attempt to replace existing standards, but to build on and augment existing standards to create a unified model supporting multiple perspectives.

Use cases

The MUDDI project has identified several different broad use cases that the model is intended to support including routine street excavations (EX), emergency response (ER), utility maintenance programs (OM), large scale construction projects (AE), disaster planning and response (DP), and smart cities programs (SC). For each of these, several basic requirements that the model needs to satisfy have been identified.  For street excavations the requirement is location of all entities with high horizontal, medium vertical accuracy (2.5D) of underground infrastructure; for large construction projects, detailed 3D geometry of underground infrastructure and detailed 3D geology;  for emergency response, interdependencies between different networks; for utility maintenance, network topology and facility location and condition; and for smart cities the ability to monitor and relate streams of data from sensors.

To provide a way for the model to be used by different types of users, the concept of profiles has been introduced. Profiles have been used for other OGC standards and allow for different levels of complexity for different domains and applications. The proposed profiles include asset, excavation, emergency, planning and integration profiles.

Reference standards

The MUDDI model is intended to build on and be compatible with many existing reference/target models.  For infrastructure these include CityGML with Utility Network ADE (Application Domain Extension) , INSPIRE Utility Networks, IMKL (Information model for cable and pipes), BIM-IFC, Land and Infrastructure Conceptual Model (LandInfra), Singapore Underground Geospatial Model, PipelineML, Underground Pipeline Information Management System, CIM (Common Information Model), Multispeak, ESRI Utility Model, and GEOfeature.  For geology, the reference/target models are GeoSciML, INSPIRE Geology, GroundwaterML, BGS National Geological Model, EarthResourceML, GeoTOP, SoilEML, IFC Geotechnical Extension, MINnD, and BoreholeIE.

Next steps

Josh outlined the next steps in the development of the MUDDI model which include implementations, experimental and prototype deployments with real world data, and estimates of returns on investment (ROI).

OGC workshop focusses on challeges to achieving interoperability for location of underground infrastructure

In July the Open Geospatial Consortium (OGC) held an underground Infrastructure ETL (export-transform-load) - Plugfest at the Fund for New York City (FCNY).  The central theme was development of a Model for Underground Data Definition and Integration (MUDDI) on which to base interoperability between different data sources and applications about the location of underground utilities and other subsurface structures.

The MUDDI ETL-Plugfest Workshop was held at the Fund for the City of New York (FCNY) on July 24-25. During the workshop there were many ver interesting presentations from the international community interested in detecting underground infrastructure and finding way to make it easier to share the information.

Josh Lieberman of the OGC described the primary motivations for developing standards to make sharing underground infrastructure (UGI) easier. There are numerous examples of disasters that have occurred because we don't know where UGI is. Lack of accurate knowledge about the subsurface is responsible for inefficiencies in construction that are a significant drag on the economy. Currently UGI data quality is poor, to a great part because we cannot the share the information that is captured during every construction project, environmental assessment or disaster planning and management exercise.

Josh piointed out that one of the biggest challenges is that there are a variety of proprietary and open data models for UGI and underground geology, each with its own special industry focus, are in use making interoperability a challenge. A partial list for UGI includes

• CityGML Utility Network ADE (Application Domain Extension)
• INSPIRE Utility Networks
• IMKL (Information model for cable and pipes)
• Land and Infrastructure Conceptual Model (LandInfra)
• Underground Pipeline Information Management System
• Power utilities transmission and distribution - CIM, Multispeak + several proprietary models from different vendors
• Gas Technology Institute (GTI) - Gas Distribution Model (GDM)
• Water and wastewater - several proprietary models

Similarly for subsurface soil, water and geology there are a number of standards in use with different applications.

• BGS National Geological Model
• BRGM SCUDD
• GeoSciML
• EarthResourceML
• INSPIRE
• GeoTOP
• GroundwaterML
• SoilIEML

Each of these models are designed for different purposes including engineering, facilities management, electric power grid performance modeling, water management, hazard assessment, and environmental assessment.  Applications have been developed around each of these models serving the different communities for which they were developed.  Josh then described how MUDDI attempts to provide a general 3D model for interoperability between these different specialized models and the types of questions such a general model would be able to answer.