Between the Poles

Real time reality capture during construction key to digitizing the entire construction workflow

Utility construction is booming globally. Almost half a trillion annual investment in capital across all the main verticals, electric, natural gas and telecom has resulted in capital investment with construction with as high as 4% growth. On top of this in the U.S. there is the recent $1.2 trillion bipartisan infrastructure bill.

Utilities are facing business drivers that are motivating them to improve the productivity of their business processes and improve data quality especially the locational accuracy of assets to provide a near real-time digital twin of their assets.  These drivers include an aging work force, the replacement of older workers by younger less experienced workers, a reliable near real-time GIS as the foundation for a smart grid, and a rapidly evolving utility business model that changes utility priorities.

Current legacy workflows

The current construction workflow for utilities is a highly inefficient, manual process a lot of which hasn't changed in 40 years. Actual construction, the middle and key part of this workflow, has remained a paper based process that has remained mostly unchanged for over 40 years now. Construction crews typically use paper job packets to locate the job site, and document any as-built changes to the job. They use the paper job packets, work order sketch, or any other piece of paper in the folder to record any required attribute information about the assets being installed. As construction activities increase and newer downstream analysis systems are brought online, such as an outage management system (OMS) system or an advanced distribution management system (ADMS), the data collection requirements grow, adding additional burdens on the construction crews. These crews work in difficult of conditions on difficult, time consuming tasks, but are still asked to record all of the required information on paper. The paperwork is prone to delays in processing at each stage of the workflow cycle. This antiquated paper-based collection of work order completion data results in mounds of paperwork from the field with all the attendant issues of hand written notes. The GIS analysts receiving these paper work packets have to try to sift out reliable data from these paper records. The result is that the data that actually gets into the GIS often is missing, inaccurate, or out of date.  Backlogs of months are not uncommon.

Real time data collection enables digitizing the entire construction workflow

Locusview has developed a digital construction management platform that digitizes the entire workflow process. It is designed with the construction crews needs in mind, matches their workflows, and simplifies their data collection tasks. Work order data is collected via a mobile application using smart forms, high-accuracy GPS, and barcode scanners. Data can be immediately accessed by the back office staff, in real time. This two-way communication can be used to resolve design changes that require due to field conditions, thus reducing invoice and billing delays.

Locusview Mobile integrated with high-accuracy GNSS receivers and barcode scanners eliminates manual data entry. Data forms are displayed based on pre-configured industry-specific data model rules using complex conditionality alongside smart forms.  Simultaneously back office managers use Locusview Web to gain real time field visibility, enabling project progress tracking, real time validations, contractor auditing, and smart alerts, ensuring compliance with safety, regulatory requirements and work processes since all stakeholders, field crews, contractors, supervisors, project managers, and inspectors are collaborating on the same job using a single platform. This fully digitized process reduces the time and effort typically required of construction crews to document their field activities, expedites and standardizes field data collection, and improves data integrity creating the foundation for a high fidelity digital twin.

A key metric we track is the as-built backlog. That's the time it takes to enter as-built data into GIS after completion of construction. That's only one part of closeout, but it's an important part.  Our customers are reporting a 70% reduction in their as-built backlogs. They are also reporting 20 % less time spent in the field. Furthermore they are seeing 50% cost savings in data collection because they're enabling field crews, people that are already out in the field, to collect this high quality data with high-accuracy GNSS devices and barcode scanners avoiding the necessity of hiring outside survey crews. This translates into better capex efficiency, putting more assets in the ground per dollar of CAPEX spend and Increased customer service, something very important for competitive industries as telecom.

This simplified data collection process is designed to fully integrate with downstream utility applications as well. The job closeout process using Locusview has been reduced from 8 months to 3 days. As a concrete example a very manual piece of the closeout process, the material reconciliation piece, has been reduced from 7 hours to 12 minutes.

Real time data collection benefits all stakeholders

Many stakeholders are involved in the the complete construction work order cycle; contractors built the job, GIS analysts updated their maps based on as-builts submitted by the construction crew, operations imports the GIS data and operates their Outage Management System (OMS), planning and engineering use GIS and other asset information to plan for future growth. The work management system uses the data to initiate, manage and closeout the work order process for each job.

In addition there are a number of "forgotten" user personas that use and need accurate data from the field. The finance and corporate accounting groups rely on data in the system of record to be highly accurate and reflect the most current state of the utilities assets. Utilities go to the bond and stock markets on a regular basis to borrow funds to build and maintain their utility systems. And potential lenders or investors rely on the accurate valuation of the company. Interest rates charged by those investors correspond directly to the health of the utility and impact the cost of funds. If the work order update processes are delayed by 2 to 6 months, then the system of record is misleading and the lenders or investors may question the financial health of the utility. In addition, delayed closeout of work in the work management system will result in increased cost of funds charges to the work order via extended construction work in progress (CWIP) and allowance for funds used during construction (AFUDC) charges that are on all of the open work orders. CWIP and AFUDC is a common practice for accounting for the cost of funds in the United States and it's a concept that's gaining momentum here in Canada as well. Also many local governments apply property tax assessments on utilities for the utility assets within their municipality. If the system of record is not up to date, then the property tax assessments will also be incorrect. Contract and management organizations also rely on the accurate and timely reporting of work completed by contractor crews, as well as, closing out of the invoicing process. Delays in documenting completed work in the field will result in delayed invoicing by the contractors for the services that they've provided to the utility.

Conclusion

The key is real-time reality capture, that gets you the benefit of driving a digital twin into utilities by capturing the most accurate, high-fidelity data at the most opportune time during construction, not afterwards where you're mapping a scar. Furthermore it's a unified solution standardizing construction data collection real time across utility and contractor crews.

 

This post is based on Danny Petrecca's and Robert Schultz's (Locusview) talk at Subsurface Utility Mapping Strategy Forum (SUMSF).

Eliminating the as-built backlog by automating field utility data capture

The as-built update backlog is the time it takes for as-builts submitted from the field after completion of construction for newly installed network equipment to get entered into your utility GIS.  It is generally measured in months which is appalling today when we have real-time or near real-time data about so many aspects of the real world from traffic to weather.

Field sourcing

The key to solving this problem is to enable crowdsourcing of updates from the people who actually do the construction, the field workers, so construction crews can make those updates where and when the work happens. In order to do that, we really need data capture tools that are much faster and simpler, in other words, more automated than today's solutions.

There are a number of enabling technologies that can change the way that we approach this problem; computer vision, machine learning, augmented reality, voice interaction, and reality capture can all play a role. A lot of these things are being driven by other industries outside the geospatial technology industry. Part of the challenge in bringing together a solution for the as-builting process is looking broadly at these different types of technologies and where they're applied and bringing them together into a solution for utilities. You need to enable the people doing the construction to capture accurate location and attribute data quickly and efficiently. Anyone should be able to use the system with minimal or no training and it should use inexpensive commodity equipment.

Automating feature recognition

As an example, we're in a new subdivision construction site and we're going to do some as-built data capture of some electric equipment using an iPad. We point our mobile device at a piece of utility equipment and the application automates the process of detecting what the equipment is. The user just taps the screen to add the feature, an electrical pedestal. Next, we point our mobile device at the neighbouring electric meter. And again, it's automatically recognized and we tap to confirm that we want to add it.  We can then scan the meter to add more detailed attributes according to rules that we've set up.

Now we want to add a cable. If the trench was still open so the cable was visible, we could automatically recognize it like we did with the other features, but since it's hidden, we select it from a list and then just tap to add points along the path of the cable. As we walk, you can see the cumulative distance of the cable path being shown at the top. Lastly, we'll add an electric cabinet in the same way and scan its attributes, including the transformer number and manufacturer on the front side. Then the KVA from the yellow 50 on the side. We zoom in more closely to get additional attributes like the serial number, work order number from the smaller label.

Once we have completed scanning the various objects, the data gets pushed automatically to the GIS with no user intervention needed. We can see the features that we just captured on a map with their attributes plus photos. The newly captured data about the equipment is immediately available in any GIS client. For example, we can see the newly captured equipment data on a handheld mobile device or it can be viewed on any web browser. The data can then be pushed on from the GIS to real-time systems like an ADMs outage management system or network management system.

The app is able to automatically recognize features and attributes using machine learning based image recognition, to tell what type of feature it is, read barcodes and QR codes, and use text recognition to capture detailed attributes. The additional attribute information also reinforces the feature recognition in some cases. YYou can also use voice recognition as a backup if there's a scenario where you have to correct something that was misrecognized or something that can't be identified correctly.

Lastly is an example of capturing very detailed attributes quickly. We captured 22 attributes in just over a second from an electric meter.

Location accuracy

Location accuracy is particularly important for underground assets. AR gives much greater relative accuracy than consumer GPS and phones do. It measures accurate distances and angles in 3D for recording of relative asset layout. In a range of tests we found AR is accurate to about 1%. As a simple example. we measured a 10 foot distance next to a tape measure. We've added a virtual pipe and you can see the measured distance in the augmented reality app is 10 inches and it's within an inch of the 10 foot mark or within about 1%. Tests of up to about 100 feet have found the same 1% accuracy. AR provides much better accuracy than you could get with anything except the very highest precision GPS.

Visual positioning system

Apple's GeoAnchors is their implementation of the AR Cloud. The idea is that as you're moving your mobile phone around among 3D objects captured in a street view scene, it uses the camera view to match what the camera is seeing against the highly accurate street view type imagery, which Apple calls look around imagery and that refines the position.

Conclusion

Field sourcing of data is key.. You need to enable the people doing the construction to capture the data, and these new technologies really open up some very exciting new ways that we can provide systems to the construction workers to enable them to capture accurate location data. We foresee that visual positioning systems are very likely going to supersede high precision GPS in a lot of scenarios.

This post is based on Peter Batty's (SSP Innovations) talk at the Subsurface Utility Mapping Strategy Forum (SUMSF).

Canadian Underground Forum begins tomorrow

You can see the program for April 29 and 30 and register here.

Speaker lineup

One of the early innovators in applying LiDAR to mapping underground pipelines, Joseph Hlady, President at Lux Modus in Calgary, Alberta will explain n his keynote the benefits that his technology has brought to the oil and gas pipeline industry. Another early innovator is Otto Ballintijn, CEO of Reduct who has developed inertial or gyro technology for mapping underground pipe networks. In his keynote he will explain the evolution of the technology including the concept, operational method, and data output of gyro mapping technology. A number of jurisdictions around the world are developing digital twins at the urban, regional and even national level. Alex Shalash of UEVO will discuss creating a city subsurface infrastructure map which unifies fragmented information and produces an intelligent digital twin. Danny Petrecca of Locusview, an early leader in capturing and managing underground data in the gas industry, will review why as-builting still remains paper-based and discuss a digital construction solution that stitches together existing technologies to create the reliable digital twin that utilities need in the age of the smart grid.

Our chief guest speaker is Jim Anspach, Chair of the ASCE 38 standards group, who will bring us up to date on the imminent 38-21 utility as-built standard. Carsten Roensdorf and Neil Brammall will introduce the Open Geospatial Consortium's work in progress, the MUDDI standard for exchanging location data about underground infrastructure. Lawrence Arcand, who has led Subsurface Utility Engineering (SUE) investigations on a national level since 2003, will provide an overview of the Canadian standard CSA S250:20 Mapping of underground utility infrastructure.

Rob Martindale, Program Manager - Utilities/Railroads at the Colorado Department of Transportation, will present an overview on how a mix of legislation and regulation has enabled Colorado to revolutionize the capture and sharing of accurate underground utility location data. Page Tucker, President & CEO at ProStar which implemented the mobile and cloud solution adopted by the Colorado DoT will speak about how the partnership between Colorado DoT and Prostar made this successful. One of the remarkable new technologies applied to mapping underground infrastructure was developed by 4M-Analytics. Harel Dan, Head of GIS and Remote Sensing, and Ophir Wainer, Director of North America Business Development, will explain how 4M-Analytics uses satellite and aerial imagery to map underground infrastructure. Leica Geosystems' IDS Georadar was one of the early innovators in ground penetrating radar. Simon Pedley, Detection Ambassador at Leica Geosystems will talk about some of the innovations in hardware and software that Leica Geosystems has developed in the last couple of years.

Government has a crucial role to play in locating and mapping underground infrastructure. Gord Reynolds and Alon Gat will discuss how Infrastructure Ontario partnered with Metrolinx and the Ministry of Transportation to establish the Utility Coordination Program (UCP), a new initiative which oversees the development of utility relocation standards and the supporting process to improve the location, treatment and relocation of utility infrastructure. Gordon McElravy, of buildingSMART Canada, will discuss buildingSMART's efforts in implementing the Municipal Infrastructure Council Program to encourage building information model (BIM) initiatives at the municipal level. Capping the first day of CUF Prashant Shukle, who was responsible for mapping and earth observation in the Canadian government for many years, will moderate a panel discussion on the role of government in underground infrastructure with panelists from the State of Colorado, the U.K. Government's Geospatial Commission, Public Services and Procurement Canada, and Infrastructure Ontario.

Cloud service for capturing and sharing point clouds of underground infrastructure

Modern reality capture technology is not only providing a high accuracy alternative to paper as-builts, but is also being used to capture the location of underground utilities and other infrastructure exposed during during excavation or exploratory digging.  LiDAR scanning or taking photos or videos with a handheld together with high accuracy GNSS equipment such as RTK or accurately surveyed control points makes it possible to achieve survey-grade accuracy for underground utility infrastructure without a survey team on site. In France a new commercial GéoCassini cloud service is available from e-Cassini that captures, processes, integrates with GIS and other geodata sources and shares accurately georeferenced point clouds of underground utilities. Furthermore the e-Cassini MarketPlace enables customers to publish and market their data stored in a GéoCassini database to the broader construction community.

Background

Without accurate maps of underground infrastructure, every construction project has the potential to become a disaster site. Incidents of underground utility damage are more frequent than many people realize. In the U.S. there are between 500,000 and 800,000 incidents every year. Every year there are injuries and fatalities attributable to hitting underground infrastructure during excavations. Inaccurate and missing information about underground infrastructure is also responsible for construction project schedule and budget overruns. According to the Federal Highway Administration (FHWA) missing or inaccurate location information about underground utilities is a major source of highway construction project delays.

Utilities have used LiDAR and photogrammetry for a number of applications involving above ground infrastructure, for example to reduce safety issues and costs when conducting a high accuracy inventory of above ground infrastructure.  Until recently modern reality capture techniques have not been applied to underground infrastructure.  But in the last few years this has begun to change. Since 2018 Lux Modus has applied LiDAR together with an accurate georeferencing device to achieve survey-grade location accuracy in "near real-time" as pipelines are constructed. As another example AVUS have developed a reality capture solution that allows the creation of as-builts accurate to ± 5 centimetres from a video taken with an Android smartphone. Together with GNSS + RTK base station or previously surveyed control points.

Commercial cloud service

In France a new GéoCassini cloud service is available from e-cassini that commercially captures accurately georeferenced point clouds of underground utilities and allows this data to be integrated with other geo data such as orthophotos, traditional GIS maps, panoramic imagery, above ground imagery from LiDAR and photogrammetry, satellite and aerial imagery, and associated metadata. I had the opportunity to speak with Patrick Maïore, founder and director of e-Cassini.

GeoCassini is a cloud-based marketplace for various types of geospatial data including underrground utilities.  The data is owned by the utility which captured it and is made commercially available to transportation agencies, construction contractors, other utilities via the GéoCassini cloud services.  For example, standard part of the planning exercise for an engineering design firm would be to consult GéoCassini to see what underground and other data is available for the intended construction site.

Furthermore GéoCassini data can be integrated and visualized in augmented reality using vGIS. e-Cassini has a technology partnership with vGIS. For example, vGIS has been used to visualize underground networks and property boundaries stored in GéoCassini for a new housing development.

Applications

One of the most recent applications of GéoCassini is capturing LiDAR scans of open trench utilities.  These could be newly installed utilities or utilities exposed during repair or relocation work.  For example, GéoCassini has been used to capture using a handheld and share location information about above and below ground data for a 200 km water network for a water utility operating in several regions of France (Herblay, Mery-sur-Oise, Saint Leu, Nanterre, Vaucresson, and Suresnes.) The video capture was performed with a handheld app that was originally developed for Android and will soon be available for iOS. The data includes point clouds captured by mobile LiDAR and utility GIS maps of underground utilities.

The process used for reality capture is simple; the field operator walks along the trench and captures a video of the trench and the video is uploaded to GéoCassini where it is transformed into a point cloud. A few minutes later an analyst in the office receives a notification that the point cloud is available. The analyst georeferences the point cloud using control points captured in parallel with the video or from preregistered control points. Accurate GNSS+RTK points can be captured at the same time as the video is recorded. Alternatively, accurate control point scan be included in the field of vision of the video. Some public works companies carry out a preliminary survey of the site using LiDAR to develop a cloud of control point clouds. Another alternative is a service offered by GéoCassini to subscribers are control point clouds in the municipalities where they regularly work. The geo-referenced point clouds are saved in the GeoCassini database and all projects that have been linked to the point clouds are automatically updated.  The information is shared amongl all stakeholders on each project.

The point clouds are used in many applications; drawing a proofing plan of the construction site, visualizing underground networks in 3D using augmented reality, and correcting and updating 2D data in the utility GIS are typical. But a big benefit is that they provide survey-grade location for underground infrastructure which enables precision engineering design with respect to the underground and the above ground.

e-Cassini has participated in two pilots in which the GéoCassini approach has been applied. In the first pilo,t which involved replacing aging house connections to the water network, after the new equipment was installed and before the trench was filled, a field technician captured a video of the newly installed equipment. The video was uploaded to GéoCassini where it was transformed into a point cloud and accurately georeferenced. The resulting georeferenced point cloud provides a high accuracy 3D image of the newly installed equipment available to all stakeholders of the project and potentially commercially available to other interested parties via the e-Cassini MarketPlace.  The second pilot involved installation of an entirely new water network for a new development. The network was installed in sections. After each section installed and prior to filling the trench before re-filling the trench, a video was recorded, uploaded to GeoCassini, converted to a point cloud and geoferenced.

e-Cassini's technology has been implemented by Veolia, a large multinational water company, and by Bouygues, a large construction company.  Veolia has conducted pilots using the technology in three regions of France, Normandy, Marseilles, and the Loire.  Veolia has applied for and is expecting regulatory approval from the local D.S.P.s, which are equivalent to public utility commissions in North America.

Bouygues Energie et Service is currently experimenting with a GéoCassini solution for the renewal of public lighting network equipment in the municipality of Pornichet. GéoCassini is being applied to improve diagnostics of existing equipment and to optimize the location and type of new equipment.

Conclusion

A benefit of the GéoCassini cloud service is that it enables the capture and sharing of survey-grade as-built records of underground infrastructure. For new infrastructure this provides a reliable record of what was installed in the ground, in other words, survey-grade "as-constructed" instead of "as-designed".  For existing infrastructure this enables discrepancies and omissions to be reported back to asset owners.

Another important benefit of the GéoCassini service is that it if very efficient and does not add to construction costs. Compared to the time required to call a surveyor to the site, video recording requires negligible time. Furthermore, the video approach does not interrupt construction work or affect scheduling and it works in most weather conditions, even at night in artificial lighting.

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.

Innovative solution efficiently captures accurate underground utility as-builts during construction

Most of underground utility damage during construction is attributable to incomplete, inaccurate and out of date records and network documentation. This data is the result of an inefficient, error-prone, and paper-based information flow from engineering, through construction crews, and resulting in "as-builts" of uncertain quality which eventually form the utility's repository of record, typically in a GIS.  Recently a mobile solution has been developed that ensures that centimetre-level accurate as-builts are efficiently captured in the field in real-time. By digitalizing and automating the collection and validation of all construction data, accurate and up-to-date as-builts become the new normal.  Already used by over half of the 20 largest energy companies in the US, the Locusview system is being extended to support natural gas utilities, electric power utilities and telecom.

Background

Without accurate maps of underground infrastructure, every construction project has the potential to become an expensive disaster site. In the U.S. there are between 400,000 and 800,000 incidents of underground utility damage every year. Every year there are injuries and fatalities attributable to underground utility damage during construction. According to the Federal Highway Administration (FHWA) missing or inaccurate location information about underground utilities is a major source of highway construction project delays. The drag on the U.S. economy resulting from underground utility damage is estimated to be at least $50 billion annually.

Inefficient, error prone construction information flow

90% of underground utility damage during construction is attributable to incomplete, inaccurate and out of date records maintained by utilities and telecoms as well as data format issues including paper and digital ink (pdf).  The reason for unreliable records of network infrastructure can be found in an information flow that is found at every utility and telecom.

The design-build-maintain information flow begins with an engineer and drafter producing a design, typically a CAD drawing, which is printed for construction contractors to use in the field in installing new underground network infrastructure. Typically the design is based solely on above-ground surveys because information about existing underground infrastructure is unreliable or missing. The construction contractor may attempt to follow the paper design drawing, but for a variety of reasons what actually ends up in the ground differs from what was designed.  The design drawing, nominally an "as-built" but typically an “as-designed”, is then returned to the records management/network documentation group who enter it into the utility's GIS where it forms the permanent record of the utility or telecom's network infrastructure. This process is slow and error-prone and backlogs of as-builts waiting to be entered into the GIS stretch into months. The result is that utility and telecom GIS data is often inaccurate, out-of-date and incomplete.

Accurate as-builts are becoming mandatory

To address the problem of unreliable as-builts and the associated human and economic consequences several governments have enacted legislation and regulations requiring the submission of accurate as-builts.  Montana has recently revised its statutes governing the installation of utilities on state highway right-of-ways.  An updated Administrative Rule mandates that as part of a new permitting process accurate electronic as-builts must be submitted to the Montana Department of Transportation (MDT) upon completion of construction.  To ensure accuracy the regulations require that the as-builts be stamped by a licensed professional engineer (PE) or professional land surveyor (PLS). 

In 2017 the Singapore Land Authority (SLA) released a standard and specifications for the procedure and practice of utility surveying in Singapore.  The standard specifies that after installing utilities and prior to filling the trenches an as-built survey must be performed by a registered surveyor to capture the location of the utilities with horizontal accuracy of ±100mm and vertical accuracy of ±100mm.  In addition the standard specifically identifies the survey equipment to be used; total station, GNSS Real Time Kinematic (RTK), or 3D laser scanning.  This standard is not mandated, but provides a baseline to be incorporated in all government construction contracts.

In response to the requirement for accurate as-builts, the challenge for contractors is to capture accurate as-builts without adding to field crew workload and without impact to project schedules.

Digitalizing the construction information flow

Locusview was founded in 2014 as a spin-out of the US Gas Technology Institute (GTI) with industry funding to develop next-generation digital construction technology for the energy and telecom industry

Locusview has adopted a paperless, digital approach based on a mobile app that makes field crews the nexus for efficiently capturing accurate as-built information.  The user-friendly mobile application makes it easy and even attractive for crews in the field to move from a manual, paper-based process to one in which all construction data is digitally captured and validated in real-time during construction.  In addition to ensuring that as-builts accurately represent what was actually built in the field, this approach reduces time and costs in field data collection, reduces the time required to prepare as-builts for submission, and ensures that data gets into the GIS faster.

During construction field crews use the Locusview Mobile app with high accuracy GPS and barcode scanners to capture as-builts, track material usage, capture photos and support other field operations such as joints, splices and welds. But the app doesn’t just capture the asset information, it also validates that the information is complete and accurate according to the company’s data requirements and construction standards. Locusview captures material data faster and more accurately with automated feature creation and attribute generation using barcode scanning. In the case of gas utilities information on all welds and joints needs to be recorded because if done incorrectly welds and joints can lead to leaks and other problems. Locusview helps ensure that these processes are carried out correctly by capturing real-time pictures and by validating welder qualifications (OQ).

High accuracy GPS is implemented in several ways.  RTK base stations can be used for real-time high accuracy GPS. In GPS denied areas a laser range finder can be deployed. Alternatively control points can be used to ensure accurate georeferencing.

Back in the office the Locusview Web application enables visibility into the real-time status of projects, making it easier to assess progress and to project revenue streams. It also provides for data validation with automated warnings and notifications of violations; review and approve pre-configured check lists; exporting data to GIS, ERP and asset management applications; reports generation and project closeout.

Benefits

There are several critically important benefits that Locusview provides.  Most critically it provides for real-time reality capture, ensuring construction quality by enabling survey-grade accurate location, attributes and material data to be recorded by construction crews as new infrastructure is installed.  This ensures that as-builts are accurate and material usage is verified and traceable. It reduces the time to prepare as-builts for submission and speeds up the process of getting the as-built information into the utility's GIS by up to 70%, which is also crucial for emergency repairs. Having full visibility over the project’s status information in real-time using Locusview’s web tool makes it easier to track project progress and to project revenue streams. The field visibility also enables supervising the work remotely, which is helpful during Covid-19 times. In addition, time and costs are reduced for capturing and managing construction data by eliminating manual paper-based processes.

Just as importantly Locusview ensures that field construction information is captured efficiently. Maintaining a survey team on site to survey newly installed pipes and cables can be prohibitively expensive especially for smaller projects.  In actual projects it has been found that Locusview can reduce surveying costs by 50%.

In summary, utilities and telecoms use the technology to build a high-quality digital twin, to support asset management strategies and to ensure regulatory compliance.

Electric power case study

VPI, a Charge company, specializes in the construction of utility-grade electric power distribution infrastructure. During a recent major project involving 35,000 feet of open trenches and 35 construction sites for a large electric power utility in California the as-built requirements changed for both above and below-ground distribution infrastructure. Among the new requirements: as-built locations had to be accurate to ± 0.2 feet (± 6 cm).   One of VPI's major concerns was the cost of keeping a professional survey crew on-site at all times to capture the location of infrastructure to survey accuracy.

VPI looked for an alternative that would lower costs and provide the flexibility of not having to coordinate with outside survey crews.  VPI's main concerns were how to efficiently meet the high accuracy requirements, how to optimize the training and education of field staff, and avoiding adding to the work load of their field crews.

Locusview implemented their solution for VPI to meet the new high-accuracy GPS as-builting requirement that included the mobile app, web app and additional RTK base station coverage. The mobile app was found to be easy-to-use after only four hours of training for field crews. Most importantly using the mobile app instead of a traditional survey crew did not add to field crew workload and was able to be implemented without impact to schedule. Remarkably for this type of project the process only required 10 days from first contact to beginning data collection. 

It enabled 16,362 feet of linear electric power assets to be mapped with a median accuracy ± 0.14 feet (4 cm).  Nearly 5,000 photos were captured for future reference. With the web application crew foremen were able to monitor construction progress in real-time to ensure data collection was complete and met their requirements before back filling trenches.  Avoiding the need to coordinate with outside survey crews resulted in a time savings of ~20% in project management for closeouts and reduced time in the field. Overall VPI realized cost savings of ~50% from reduced man-hours.

Conclusion

This remarkable application provides a solution to the decade-old challenge of efficiently capturing high accuracy as-builts in real-time and eliminating the problem of as-built backlogs.  Gas is the most dangerous underground utility and it is not surprising that the development of the Locusview solution was fostered and heavily adopted by the gas distribution industry.  Jurisdictions are beginning to require high accuracy as-builts from energy companies, electric power utilities, water utilities and telecom as a basis for a digital twin. To capture accurate as-builts efficiently is the challenge that Locusview addresses. The VPI case study shows that Locusview is able to provide efficient solutions for capturing accurate as-builts without adding to field crew workload and without impact to project schedules. This solution offers important benefits for any field constructed linear asset.

Innovative technology uses AM radio waves to detect underground infrastructure

In the last few years there have been important advances in technology for detecting underground infrastructure including capturing ground penetrating radar (GPR) scans at highway speeds, combined GPR and LiDAR scanning for simultaneous above and below-ground mapping, software to simplify the interpretation of GPR scans, inertial mapping of pipe networks, and acoustic locating to name a few.  Most recently a new technology originally developed for military purposes uses AM radio waves to detect underground assets.

Background

The $10 trillion global construction industry is facing a crisis. For many of the world's advanced economies including Japan, Germany, U.S., South Korea, and U.K. construction productivity has been stagnant or even declining for decades. Virtually all of the funding for infrastructure was sourced from government who were looking for a social return on the investment. Since the mid 2000s, an increasing proportion of investment in infrastructure has come from private sources; pension funds, insurance companies and sovereign wealth funds which together manage over $60 trillion. These sources of investment are expecting a financial return and that is driving a growing investment in construction technology to improve productivity. Historically, investment in research and development by the construction industry has been very low compared to other industries. Several years ago a McKinsey Global Institute study compared the degree of digitalization of nearly 30 industries and concluded that construction ranked right at the bottom with hunting. But there are signs of a change. Venture capital investment in technology startups in the construction sector is growing especially since 2018.

Detecting underground infrastructure

In the last few years there have been important advances in technology for detecting underground infrastructure. Advances in ground penetrating radar (GPR) now make it possible to safely capture scans at roadway speeds. One of the important challenges of GPR is interpreting the scans which has required a trained geotechnician. New software developments are simplifying the interpretation of GPR scans, enabling surveyors and other professionals to use GPR technology effectively. LiDAR is being applied to efficiently capture the location of newly installed underground pipelines. The simultaneous capture of above and below-ground scans using LiDAR and GPR creates a complete assessment for construction projects. Inertial mapping can be used to map underground pipe networks for up to two kilometers. Advances in acoustic locating show the technology can be effective in detection underground objects down to 30 feet.

Detecting underground infrastructure with AM Gradiometer

KCI reports that the AM Gradiometer can be configured to be hand-held or placed on a cart.

KCI is an engineering, planning and construction firm with customers across the United States. KCI recently had the opportunity to pilot and is now utilizing an innovative technology AM Gradiometer (AMG) to detect and map underground infrastructure. This is a patented tool that uses AM-band transmissions from radio station towers to detect subsurface objects. The device’s antennas detect AM radiofrequency signals reflected from underground assets. The device consists of multiple receiver antennas.  The spacing between the antennas determines the depth at which the device detects objects. A typical configuration includes three antennas. When closely spaced they detect shallow targets (5-10 feet). Intermediate-spacing detects targets at medium depths (10-20 feet), and more widely-spaced antennas can detect deep targets (30-50 feet).  The data can be exported in several forms including as a spreadsheet, a Google Earth map, and a CAD file.

An AM Gradiometer scan is performed in a grid pattern over an area of planned excavation. The device can be pushed on a cart or carried by hand.  The AM Gradiometer also includes GNSS capability and the ability to be tracked with a total station for accurate georeferencing. The device can detect electrical conductors, metal pipes, non-metallic conduits, liquid or air-filled void space, natural gas or fuel lines, brick or concrete sewer lines, shielded fiber optics cables, and hydrocarbon or saline moisture plumes.

Digitally capturing the location of underground utilities detected using electromagnetic techniques

The industry standard for locating underground utilities is a manual process involving the use of an electromagnetic (EM) wand to detect underground cables and pipes.  The detected location is typically recorded by painting or otherwise marking the ground.  I recently had the opportunity to chat with Kieren Tinning of Terraflow Geomatics, whose Utility Mapper product adds significant value to an industry standard underground locating tool by enabling the digital capture of the location of underground pipes and cables detected with an EM wand and the generation of 3D data for integration with CAD and GIS applications. On a recent depth of cover survey of a thousand kilometre gas transmission line it was found that because Utility Mapper automated most of the data capture and geoprocessing staff time was reduced by 42 %.

Background

In the U.S., underground utilities are a major cause of highway construction delays. Knowing where things are underground has become important enough that in several countries around the world - France, the Netherlands, Singapore, and the U,K., initiatives are already underway to create national digital twins of above and below-ground infrastructure. Recently there have been important technical advances in several areas that are have brought the feasibility of cost-effective mapping of underground infrastructure at the municipal, regional, and national level within reach.  One of these is to digitally capture the location of underground utilities detected using remote sensing technologies such as electromagnetic (EM) and ground penetrating radar (GPR).

Remote-sensing tools for underground utility detection have been available for decades. Electromagnetic (EM) detection wands can be used in several different ways. Passively detecting utilities with EM is used for services that emit naturally emit a frequency such as electrical cables (50 or 60 Hz).  Another approach is to physically connect a signal generator to a service.  This method requires physical access to the service, usually by way of a surface feature that is connected to the service such as a valve. Another technique is to introduce an active signal into a line through electromagnetic induction (EMI). The advantages of EM detection are that it is simple to use and effective for detecting conductive underground infrastructure.  Ground penetrating radar is an alternative technique for underground detection, but in some soil types such as aggregate and clay GPR does not perform well. Without supplementary information GPR does not identify the type of utility (gas, water, electric, fiber optic). In addition GPR requires an expert, typically a trained geophysicist, to interpret the scans. As a result EM detection has become the industry standard.

One of the serious deficiencies of EM is that most wands do not permit the digital capture of the location of detected underground objects.  Typically EM detection is a manual process in which the location of underground infrastructure is recorded by painting or otherwise marking the ground.  Terraflow Geomatics' Utility Mapper changes this by enabling the digital capture of the location of underground pipes and cables detected with an EM wand. Using together RTK devices such as Trimble's Catalyst enables highly accurate location information to be simultaneously captured.  Terraflow's Data Engine automates the synchronization of this data back to the desktop for integration with AutoCAD, Microstation,  ArcGIS and other applications.

Customer experience

PVS Contractors performs large scale depth of cover and other locate services for pipeline operators. Prior to acquiring Utility Mapper, calculating the depth of cover was a manual process in which the depth was recorded manually and correlated with the GPS location. For a survey of a thousand kilometre pipeline, this typically would require eight full time staff for eight months, plus an admin staff member and supervisor for several days per week to check and confirm the data. For a recent large scale depth of cover survey for a gas transmission pipeline running from Windsor to Montreal, about a thousand kilometres, PVS deployed Utility Mapper together with Vivax-Metrotech electromagnetic locators and Trimble Catalyst, which enabled survey-grade positioning with an Android smartphone.  Utility Mapper automated most of the capture and processing - integrating the GPS and electromagnetic locate information and wirelessly synchronizing the location and depth of cover information directly to ESRI’s ArcGIS Online for quality assurance and quality control. This reduced staffing requirements from 64 to 47 person-months. Furthermore, the Utility Mapper solution reduced the data review time for a supervisor (prior to sending the data to the client) to one hour per week .

Summary

Terraflow's Utility Mapper is an important advancement.  It adds significant value to the industry standard EM underground utility locating tool by enabling the cost-effective digital capture of 3D location data captured by EM devices and RTK GNSS and streaming this data to users' CAD and GIS applications.

Centimetre-accurate as-builts efficiently captured with a smartphone

Without accurate maps of underground infrastructure, every construction project has the potential to become a disaster site. Incidents of underground utility damage are more frequent than many people realize. In the U.S. there are between 400,000 and 800,000 incidents every year. Every year there are injuries and fatalities attributable to hitting underground infrastructure during excavations. Inaccurate and missing information about underground infrastructure is also responsible for construction project schedule and budget overruns. According to the Federal Highway Administration (FHWA) missing or inaccurate location information about underground utilities is a major source of highway construction project delays. The drag on the U.S. economy resulting from underground utility damage is estimated at $50 to $100 billion annually.

90% of underground utility damage during construction is attributable to (1) incomplete, inaccurate and out of date records maintained by utilities and telecoms and (2) data format issues including paper, digital ink (pdf) and raster (imagery) records. As one customer said, existing records are typically 15-30% off the mark. Another contractor reported that records are not updated after relocation of assets. The result of these and other issues is that excavators are often working blindly.

AVUS is a recent startup that has been incubated by Vinci Group , a French construction company with annual revenue of €48.1 billion. In 2019 Vinci ran 290 000 construction worksites. AVUS is a service company providing services for capturing accurate as-builts and visualizing underground infrastructure.   Recently I had a chance to chat with Sebastien Magat, the entrepreneur behind AVUS.

As-built service

AVUS have developed a reality capture solution that allows the creation of as-builts accurate to ± 5 centimetres from a video taken with an Android smartphone. Currently in use at 30 construction sites, the workflow is very simple; open the AVUS app on a smartphone, connect to a local RTK base station or use known control points, enter project and site information, use the app to create a video by walking along the open trench after installation of the utility, upload the video to the AVUS cloud site where a point cloud is created, georeferenced and scaled using RTK or known or recorded ground control points, and receive the as-built in the form of point cloud (.las), orthophoto, and CAD drawing (.dwg). A similar process can be used with utilities exposed during construction to amend and correct existing records.

The process of generating a DWG file from the point cloud is currently a manual process, but with the rapid advances in feature extraction technology, aided by machine learning algorithms and the compilation of training data by EPRI and others, in the future this process is expected to be increasingly automated.

A benefit of the AVUS as-built services is that it provides reliable records of underground infrastructure certified to ±5 centimetres horizontally and vertically. For new infrastructure this provides a reliable record of what was installed in the ground, in other words, "as-constructed" instead of "as-designed".  For existing infrastructure this enables discrepancies and omissions to be reported back to asset owners. The as-built records are PAS 256 compliant and integrate with existing utility GIS databases.

Another important benefit of the AVUS as-built service is that it does not add significantly to construction costs. It is very efficient compared to the time required to call a surveyor to the site - the AVUS video recording takes less time than it would take for the surveyor to drive to the site. Furthermore, the video approach works in every weather condition, even at night in artificial lighting. This enables the construction crew to continue with their work, instead of having to wait for the surveyor to get to the site and conduct the survey.

Augmented reality

AVUS compiles existing 2D and 3D records and site investigation results into a 3D model that can be visualized in augmented reality on a handheld.  An Android app has been developed that uses Google AR Core to project highly accurate holograms on a smartphone. Accurate positioning is achieved by connecting to a local RTK base station or by calibrating to known features in the field of view.

The app is easy to implement and use and it integrates with existing utility GIS databases. The benefits of this AR approach is that increases productivity by enabling more rapid location of underground networks and results in reduced risk of underground utility damage.

AVUS provides an important service that captures the location of underground infrastructure efficiently, improves the quality of location data, and makes the data easily accessible to engineers and contractors in an augmented reality view in the field.

First substation built using full life-cycle BIM construction goes live one month early

Hubei Electric Engineering Corporation (HEEC) was this year's winner of the Bentley Year in Infrastructure Communications and Utilities award.  One of the key objectives of the ground-breaking CNY 120 million (US$16.8 million) Miluo Western 220kV substation project was to reuse the design BIM model and data during construction and to provide a virtual reality BIM model to the owner on completion of the project to improve operations and maintenance procedures. As a result of the application of digital technology including reality modeling using UAVs, full life-cycle building information modeling (BIM), integrated BIM and geospatial, construction monitoring, and construction simulation, construction was completed 30 days ahead of schedule saving CNY 6.3 million (US$ 895,000).

Hubei Electric Engineering Corporation (HEEC) began applying 3D design to projects beginning in 2013. In 2017 the State Grid Corp began to promote 3D design and held a competition to select the best design companies to carry out 3D demonstration projects. HEEC came in first in this competition and was awarded the Miluo Western 220kV substation project. In addition 3D design standards for China's electric power industry had been developed and HEEC was a leading contributor to six of these standards. On this project HEEC strictly implemented these standards during design.

The Miluo Western 220kV substation supplies power to 160,000 customers in a 16 km² area. The total investment in the 10 month project was CNY 120 million ($16.8 million).

Digital technology including reality modeling using UAVs, building information modeling (BIM), integrated BIM+geospatial, construction monitoring, and construction simulation, enabled collaboration between site preparation, mechanical design, electrical design, protection, and communications design teams.  The challenges that HEEC targeted on this project were several.

First of all, the site was constricted because of existing houses and a key objective was to minimize impact on the existing buildings. By scanning the area and using geospatial reality modeling techniques, the area occupied by the substation was reduced by 22% saving CNY 2.5 million and avoiding the demolition of six houses.

Secondly, the project was the first to apply the 3D standards mandated for the entire Chinese utility industry. The Miluo Western 220kV substation is among the first batch of 3D demonstration projects based on 3D standards.  This is the first of the 3D demonstration projects to go into operation, in June 2019.

Third, because the site chosen for the substation was constricted, cables and equipment were closed together than in other substations. HEEC reengineered the design process and developed a series of system processes to ensure the quality of 3D design by collaborative design between mechanical, electrical, protection, communication, and site preparation teams. During design, clash detection between these different elements avoided 30 instances of rework during construction saving CNY 800,000.

Fourthly, from the beginning the objective was to find a way to reuse the design BIM model during construction. Typically a separate BIM model is developed by construction contractors to be used during construction. HEEC investigated ways that 3D pdfs, mobile handhelds, cloud storage, and other technologies could be used to enable the 3D design BIM to be used to schedule construction.

Fifth, HEEC used reality capture techniques including UAVs to monitor construction progress on a daily basis. Due to uncertain factors factors in the construction process, there will necessarily be deviations between planned and actual construction. By monitoring these on a daily basis ensured that these do not hold up the project. At YII2019 HEEC showed an amazing video with actual and planned construction side by side where each frame represented a day.

Finally, an important goal was to use digital technology to improve operations and maintenance procedures. At the end of the project HEEC was able to hand over to the State Grid a virtual reality BIM+geospatial model designed to improve operations and maintenance procedures.

In summary digital technology including reality capture, construction simulation, and full-lifecycle BIM resulted in tangible benefits; avoiding the demolition of 6 houses and reducing the area required for the substation by 22% for a saving of CNY 2.5 million; significant savings in materials saving CNY 210,000; avoided rework saving CNY 800,000; reducing design time by 65 days; and completing construction 30 days ahead of schedule generating economic benefits of CNY 1.5 million. Taken together the total investment was reduced by CNY 6.3 million (US$ 895,000). In addition by providing a virtual reality model to the owner on completion of the project it is expected that substantive savings will be achieved during operations and maintenance.