Proceedings Template - WORD€¦ · Web viewAlternatively, the use of multi-utility tunnels proposed by some researchers [7] would eliminate the need for detection equipment in

12th International Conference on Ground Penetrating Radar, June 16-19, 2008, Birmingham, UK

Extending GPR Utility Location Performance - The Mapping The Underworld Project

Rogers1, C.D.F., Zembillas2, N., Metje1, N., Chapman1, D.N. and Thomas1, A.M.1 School of Engineering (Civil Engineering), University of Edgbaston, Birmingham, B15 2TT, United Kingdom

2 The TBE Group, 380 Park Place Blvd., Suite 300, Clearwater, Florida, FL33759, USAemail [email protected]

Abstract - The lack of accurate, and all too often any, prior knowledge of the location of buried utilities causes signifi-cant problems for any construction project involving excava-tion. Consequently, over recent years much effort has been expended to mitigate this situation through attempting to de-tect and locate utilities using geophysical techniques, primar-ily based on ground penetrating radar (GPR). However, such methods do not yet provide consistency of detection and/or accuracy suitable for all stakeholders needs: a problem which is the subject of much current research. This paper considers the overall process of managing and recording data on utility installations based on the extensive work of the Mapping the Underworld (MTU) project. MTU’s out-comes are shown to be appropriate for integration into an in-ternationally standardized Sub-surface Utility Engineering (SUE) practice, modelled around that used in North Amer-ica. In so doing, the paper will present a vision of how the management of utility mapping and location can be signifi-cantly enhanced through the integration of tried and tested best-practice guidance and much improved location equip-ment. It will conclude that an ad-hoc approach to utility lo-cation is simply a continuation of current practices, but that a holistic methodology provides the way forward if the so-cial, financial and environmental impacts of poor utility lo-cation data are to be properly mitigated and 100% detection rates without local proving excavations are to be ap-proached.

Keywords - Mapping the Underworld (MTU), Sub-surface Utility Engineering (SUE), utility location and mapping.

I. AN INTRODUCTION TO MAPPING THE UNDER-WORLD

The location of buried utilities is of significant con-cern primarily due to the large costs associated with sur-face excavation for utility installation or repair. This has been estimated as £7 billion per annum in the UK alone [1,2], comprising £1.5 billion in direct construction costs and as much as £5.5 billion in social costs. Therefore, it is not surprising that poorly recorded utilities are problem-atic, as they can lead to lengthy delays to construction works, either for the purpose of locating their positions during project planning or when unexpectedly found dur-ing excavation. For these reasons, the use of geophysical methods for utility location has become popular in recent years.

Ground Penetrating Radar (GPR), in particular, has become a central technology in the field of geophysical utility location, largely due to its flexibility in operating through a variety of ground conditions and due to the speed at which it can traverse a survey area. However, de-spite its advantages, it suffers from two significant adverse influences: the depth at which it can detect utilities is lim-ited by attenuation in clay soils and attempts to mitigate this, such as through reduction in signal frequency, can make smaller targets much harder to identify.

To address these limitations, a number of projects in Europe have been working on the overall problem of util-ity location: Mapping The Underworld (MTU, see [3] and www.mappingtheunderworld.ac.uk), VISTA ('Visualizing Integrated Information on Buried Assets to Reduce Street-works' - see www.vistadtiproject.org), and ORFEUS ('Op-timizing Radar to Find Every Utility Under the Street', see www.orfeus-project.eu). While all of these projects are important to utility location research, this paper will de-scribe the role of MTU.

MTU came about after congestion on urban highways, in the UK and worldwide, was identified as one of six key issues by the NETTWORK project (Network in Trench-less Technology, see ttn.bham.ac.uk), a collaboration be-tween industry and academia set up to debate the prob-lems and research needs related to trenchless construction practices. NETTWORK was funded by the UK Engineer-ing and Physical Sciences Research Council (EPSRC) and hosted workshops and stakeholder meetings that included consideration of potential solutions to the problems of util-ity congestion in the sub-surface [4]. An international workshop consisting of delegates from the UK, US and Holland further established research needs and the out-come was a consensus that a number of related projects were necessary to improve the situation now and in the long-term [1].

This led to acknowledgement by the UK Government of the general research needs and EPSRC subsequently chose this topic for its first IDEAS Factory, or sandpit (see www.epsrc.ac.uk), which is a novel means of awarding funding to the UK academic community involving a highly multidisciplinary mix of academic and industry participants. This drives lateral thinking and results in novel methods for the formulation of solutions to research problems. The Mapping the Underworld (MTU) sandpit


identified that a multi-sensor location tool would be essen-tial for comprehensive location of buried infrastructure, because it could compensate for the weaknesses of any one method and allow cross-corroboration of location data for utilities identifiable by more than one method.

However, it was further identified that parallel re-search projects were required to cover precision mapping (even in urban canyons), data integration from various records and sources, and asset tagging to ensure that new or repaired utilities could be made more visible to location equipment. Therefore, based on these requirements, MTU was funded by EPSRC to investigate the feasibility of sev-eral novel approaches in parallel with improvements to existing technologies. The results of this are intended to provide a single multi-modal approach to the remote loca-tion, and ideally the identification and ultimately possibly even condition assessment, of buried assets. It was de-cided that the system should be deployable not only from above ground, but with support from GPR equipment in-serted into exiting utility conduits.

The mapping and data integration elements of MTU spawned a follow-on project entitled VISTA, which is funded jointly by the UK government (see www.dti.gov-.uk/technologyprogramme) and industry. VISTA aims to bring together existing paper and digital records with data from satellite- and ground-based positioning systems to formulate the means of creating a three-dimensional elec-tronic map of buried utilities. This is a pressing goal, given the requirement of the UK Traffic Management Act that all utility providers be able to exchange digital utility positions by June 2008.

Figure 1. Delegates at the first MTU workshop.

An important element of MTU is collaboration, which requires intimate interaction between all aspects of the re-search programme: a difficult goal to aspire to given the highly multi-disciplinary nature of the research topic. In-ternally, MTU manages this element through regular meetings involving all researchers and, externally, it is managed through the MTU Network, which actively seeks to engage with other research programmes and draw in new project partners in academia and industry. Such close collaboration with industry stakeholders has been facili-tated by five different workshops, each well attended and

illustrated in Figure 1, and a widely distributed question-naire [5] on the accuracy and depth requirements of stake-holders.

The questionnaire also resulted in MTU gaining a unique insight into the problems faced by these stakehold-ers, through the additional comments they provided in their responses, some of which being included throughout this paper to illustrate their needs. The active partner-seeking has been very successful, and has allowed a fur-ther important element of utility management to be incor-porated into the work of MTU. This element provides the focus for the rest of this paper and is the answer to one simple question: how should one manage the use of the new location, positioning and validation outcomes in a co-herent manner and in a way that provides location and recording outcomes that are entirely relevant to the needs of all stakeholders? Through collaboration between MTU, in the UK, and the TBE Group, in the USA, a method of achieving the answer to this question is being developed based on a practice known as Sub-surface Utility Engi-neering (SUE). This paper summarizes the main elements, and benefits, of SUE and details ways in which MTU in-tends to integrate their research outcomes into it such that both are improved and a sophisticated methodology for utility location is created.

II. SUB-SURFACE UTILITY ENGINEERING

2.1 The Central Elements of SUESUE (see e.g. Figure 2) developed in North America

as a solution to the common practice of either ignoring utilities until found in excavations, or using single-utility location services, both of which could result in problems for developers due to the unexpected encountering of utili-ties during construction work.

Figure 2. SUE in Action in North America.

SUE therefore arose as a system that allows utility re-lated risks to be properly managed and potential impacts on safety, construction costs and the environment to be mitigated (for more detail see [6] and www.tbegroup.-com). It contains five central elements: Defining the scope of the works.


Site-based designating activities. Locating geophysically detected utilities. Managing and communicating data. Managing conflict and risk.

2.2 Defining the Scope of WorksDefining the scope of utility location works simply in-

volves asking questions such as what does the client want using alternative methodologies, and how can it be achieved, and to what extent can it be achieved? This en-sures that all involved parties are working toward a com-mon goal and in so doing maintains confidence in the SUE system. While such simple questions may seem to have obvious answers, this cannot be assumed as clients often do not fully understand the limitations of utility location equipment and their performance potential in a site-spe-cific context.

For instance, in the MTU questionnaire one respon-dent said that ‘First hand experience of ground radar has shown it to be either very useful or totally useless, a mid-dle ground needs to be reached’. From such comments is can be seen that the complexity inherent in undertaking an effective utility location survey can result in confusion over the efficacy of a survey if clients are not aware of the quality of data, and potential variations, at an early stage.

The agreed scope of works are formalized into a writ-ten document that specifies what will be done and what can be realistically achieved from it. In our increasingly cost-conscious world it is also important to note that the agreed activities may largely be derived on a cost-benefit basis, so the agreement of levels of risk associated with the agreed level of utility location must be made clear.

The MTU/SUE Goal: To make geophysical utility location a transparent operation where all stakeholders are aware of what can be achieved on a cost-benefit ba-sis, and thus what cannot be expected in each case.

2.3 Site-based designation activitiesDesignating is the process of using a surface geophys-

ical method, or methods, to interpret the presence of a subsurface utility and mark its approximate plan position at ground level. It currently involves choosing the most appropriate geophysical location technologies, on a job-specific basis, and using them to attempt to find all utili -ties detectable within the site area. In US SUE, planning of this element is critical as, to show that an appropriate standard-of-care has been applied, location professionals must be able to demonstrate that they have made use of the latest geophysical techniques and the appropriate com-bination of technologies applied sequentially to assure ac-curacy and completeness. Therefore, while GPR is the central technology, simple use of it in isolation would not necessarily constitute an appropriate action. The MTU philosophy, which is dependent on Phase 2 of its planned programme for its realization, is to combine the various

geophysical techniques into a single device such that intel-ligent data fusion techniques can be applied to the outputs to improve detection rates.

Also, as one questionnaire respondent said, ‘There are many types of utility detection equipment available in the market. No information is available about their perfor-mance accuracy’. This is an important factor in undertak-ing a utility location survey as the surveyor must choose from a range of technologies based on experience. Con-versely, for less experienced personnel, it provides the po-tential for the selection of inappropriate, sometimes ‘over-sold’ location equipment, together with potentially re-duced detection rates.

For this reason, the MTU work includes two elements that will help ensure that location personnel are ade-quately able to plan their surveys. Firstly, through the work of Leeds University, the potentially difficult task of collating all available utility record data for a site will be simplified through development of an internet-based por-tal. This will provide a ‘one-stop-shop’ for obtaining all relevant records and so will allow improved advance plan-ning through greater knowledge of the types and sizes of utilities likely to be present and, perhaps only approxi-mately, where they might be.

Secondly, through progression of a proposal for a test site by Sheffield University, incorporating a wide range of real-life streetscapes over realistic buried utility layouts, it will become possible to provide geophysical utility loca-tion training and certification. This should help ensure a greater consistency of expertise and will be accompanied by equipment testing to determine the level of accuracy they can achieve, which will help ensure that answers can be given to stakeholders comments, such as the one quoted at the start of this section.

MTU also plans to take advantage of the greater prac-tical knowledge of surveyors, obtained through the in-tended training opportunities at the test site, by providing them with a number of new technologies for use in utility location. For instance, a novel in-pipe GPR unit is being developed that will allow surveys to be carried out directly through the soil, thereby removing the need to detect re-flected signals. Also, a new acoustic technique is being developed that will make use of vibrations produced either at ground level or by directly coupling to a pipe. This will provide a significant extension to GPR as acoustic tech-niques can work well in wet clays in which electromag-netic signals are often quickly attenuated.

While GPR and acoustics are not entirely new, two other MTU systems are more novel: the application of low frequency electric and magnetic fields. The proposed use of electric fields is based on the field produced by actively injected low-frequency electric current through soil, and the variations that occur when it is measured above ground over pipes and cables. It shows promise for use in wet clays and for detecting small plastic pipes. The low frequency magnetic field system is intended to aid in the


location of utilities through detecting variations in the magnetic fields produced by nearby electricity cables.

The MTU/SUE Goal: To allow geophysical utility location to be planned and instigated based on the best possible planning data and deploying simultaneously and intelligently fusing the outputs from the best of a wide range of location techniques to complement GPR and operated using accredited operatives.

2.4 Are Utilities Adequately Detectable? An important question associated with the difficulties of locating buried utilities is: why are they not designed to be easily found? As one questionnaire respondent said ‘I am concerned about the use of plastic pipes for services such as gas and water nowadays which are generally more difficult to detect’. Therefore, should we not be us-ing all techniques at our disposal to ensure the detectabil-ity of the utilities we bury?

A number of traditional techniques exist to deal with detection problems, most notably the use of metallic tracer wires. These allow transmission of a signal through the ground that can be detected at surface level, assuming the ends can be found. Alternatively, the use of multi-utility tunnels proposed by some researchers [7] would eliminate the need for detection equipment in some cases by exactly defining in advance where services will be installed. More novel systems could also be based around intelligent se-lection of backfill materials to provide a contrast in GPR surveys.

Figure 3. Tags for Improving GPR Visibility of Utilities.

Even more novel is the development of new tags by Oxford University that could be attached to pipes either during manufacture or when exposed during excavation. These small circuit boards, early prototypes of which are illustrated in Figure 3, require no power supply, instead passively amplifying GPR signals and so increasing the strength of reflected signals. Being cheap, simple and durable they provide significant scope for improving the visibility of utilities to GPR signals.

Of interest also is that the collaboration aspect of MTU brings with it the advantage of links to other aca-

demic projects. One such project, being undertaken at the University of Birmingham, is known as Smart Pipes and involves the investigation into the potential for installing wirelessly connected sensors on plastic pipes. As well as monitoring flows and assessing the condition of the pipe, it is possible in the future that these sensors will also be able to detect metallic excavation equipment and warn the utility operator of the potential danger; it is even conceiv-able that such sensors could communicate with a radio re-ceiver in the excavator cab to warn the driver.

The MTU/SUE Goal: To ensure that, in future, no newly installed buried utility is invisible to geophysical utility location devices.

2.5 Soil-Signal InteractionsThere is one central factor that is common to the in-

terpretation of all GPR utility location surveys, that being the soil through which signals must travel between the transmitter and receiver. As soils have a significant effect on the strength and velocity of GPR signals, which can vary significantly with frequency as a result of the phe-nomenon known as electromagnetic dispersion, a full un-derstanding of its electromagnetic properties must be con-sidered central to an understanding of the difficulties in-herent in geophysically detecting buried utilities.

Therefore, for the soils aspects of MTU, a novel ap-proach has been taken. A new measurement methodology has been devised to obtain full data on the relevant elec-tromagnetic (EM) properties of soils over a wide range of water contents and signal frequencies. Also, as soil EM properties need to be measured in the laboratory and in the field, testing apparatus has not been limited simply to the use of coaxial measurement cells. Instead, probes com-monly used for Time-Domain Reflectometry have been adapted to provide directly measured frequency-domain data in the field. An example of one of these probes is il-lustrated in Figure 4.

Figure 4. Modified TDR soil probe.

The resulting data are illustrated in Figure 5, which shows full velocity spectra for a naturally occurring Lon-don Clay. Two important geotechnical features are in-cluded in the figure: WP being the water content below which the soil becomes friable and non-plastic (known as the plastic limit), and WL being the water content at which


the soil begins to behave as a liquid (known as the liquid limit).

These two limits highlight a particular feature of the MTU research: rather than simply studying the geophysi-cal properties, consideration is being given to how they re-late to other soil properties, particularly those associated with geotechnics. This is an important factor as few data are available in the literature relating to EM properties over the full range between the plastic and liquid limits, yet these limits form the upper and lower bounds of water contents that can be expected for soils under most field conditions [8].

Also, by studying the EM properties within these wa-ter content ranges, field applicable relationships between the EM properties, water content and such geotechnical parameters as dry density and particle density have been found to simplify velocity prediction in comparison to the large number of mixing models available for lower water contents. This, and related research outcomes, are being taken advantage of to construct a methodology for esti-mating GPR signal velocities based on geotechnical data [9,10].

Figure 5. Measured velocity spectra of a London Clay.

While these advances could make geotechnical re-ports, such as those commonly commissioned for con-struction projects, a useful source of data for planning GPR surveys, they also provide a further significant op-portunity. In the UK, geotechnical datasets are maintained by the British Geological Survey (BGS). While they do not currently contain high resolution data for all areas of the UK, they represent a significant source of information that could be used for soil EM predictions. Therefore, the MTU research team is collaborating with the BGS with the intention of working toward geo-spatially mapping GPR relevant soil properties in a manner that allows their use for desk studies and the planning of properly informed GPR surveys.

Although initial work has focussed on velocity mea-surements, research is also ongoing to use the data to pro-vide estimates of signal loss over distance (i.e. attenua-

tion), over the same wide water content and frequency ranges.

The MTU/SUE Goal: To ensure that advances in geophysical utility location are accompanied by ade-quate knowledge of the media through which signals travel - particularly the soil - and that prior informa-tion on this can be obtained in order to allow improved planning and data interpretation.

2.6 Locating Utilities There are two very important aspects of utility loca -tion that cannot be summarized better than through the words of one questionnaire respondent: ‘It’s extremely im-portant to know as accurately as possible the depth, plan position and also if possible the type of service that is be-ing detected. The accuracy of the detection through regu-lar calibration testing of the detection machine is also vi-tal.’

While the need for regular calibration and testing of equipment will be addressed through the proposed MTU test site, that equipment must then be able to determine, as accurately as possible, the location of any detected utility. Also, this location must be suitable for use in utility data-bases and for future site re-location activities. In the past, location data would have been recorded relative to ground features which, as well as having limited accuracy, can become obsolete when the features used for location are removed. Therefore, current systems rely on global posi-tioning systems (GPS), as illustrated in Figure 6, which are capable of providing absolute (X, Y and Z) coordi-nates that remain valid regardless of surface features and which are more suitable for easy inclusion in computer aided design (CAD) software and utility databases.

Figure 6. Using GPS to find the exact position of a utility.


However, GPS systems suffer from difficulties in ac-curately determining positions where there are large obsta-cles around them, such as tall buildings, reducing the number of satellites visible to the GPS system. Areas where this problem occurs are known as ‘urban canyons’. MTU seeks to alleviate this problem through the work of Nottingham University and VISTA, who are investigating two potentially helpful methods: integration of available satellite constellations to increase the number of satellites useable for location, and use of ground-based transmitters.

There are four main satellite constellations, these be-ing US GPS, Russian Glonass, Chinese Compass and EU Galileo, but location devices are generally based on one constellation, so there are obvious advantages to using more than one as the number of visible satellites in urban canyons is thereby increased. Ground-based transmitters, mounted for instance on tall buildings and whose position is accurately established, will appear to location devices as satellites, further increasing visible satellite numbers.

However, while GPS systems can accurately record the plan positions of utilities, they cannot record the Z co-ordinate without excavation. As current geophysical utility location systems are not considered suitably accurate in terms of depth estimation, minimally intrusive vacuum ex-cavation, as illustrated in Figure 7, is widely used in US SUE practice to determine depth.

Figure 7. Vacuum Excavation.

As a questionnaire respondent stated ‘For critical sup-ply situations, or where there is detection ambiguity due to utility congestion, then some degree of vacuum excavation is essential...’. However, MTU does not agree that vac-uum excavation is absolutely essential to Z determination, rather that it is required due to the limitations of current location technologies. For instance, common-midpoint measurement techniques can be used to determine depth, but this is time consuming for utility location where there may be many utilities to record. However, through use of antenna arrays with their GPR equipment, MTU intends to allow greater accuracy in determining depth. Also, through their research into soil electromagnetic properties,

they hope to greatly improve the quality of velocity pre-diction from soil data.

The MTU/SUE Goal: To ensure that records of utility locations are as accurate as possible, both during recording and in the future, and that data are fully three-dimensional.

2.7 Managing and Communicating Data Managing and communicating data is generally achieved through use of utility databases and CAD draw-ings. However, a questionnaire respondent was clear that this may not be the whole story in stating that ‘It is not only important to obtain the correct information with re-gards to location and depth of utilities, but to present that information in a clear and user friendly format.’ Clearly, the way in which the data are represented is a significant element in the success of any data management system.

One way of improving upon current data communica-tion methods is to supplement traditional use of 2D plans, illustrated in Figure 8, with 3D data visualized using vir-tual reality, as illustrated in Figure 9. The approach being undertaken in this regard by MTU is twofold: firstly data will be available for virtual 3D visualization in real-time during the survey and, back in the office, it will be possi-ble to use the survey data, and utility records, as the essen-tial data sources for visualization during project planning. This will allow much improved interpretation of data, par-ticularly in terms of visualizing depths.

Figure 8. Survey ‘data’ only become ‘information’ if they are properly communicated.

Also, the way in which data are stored is of significant importance. The development by MTU of a new ‘one-call’ internet portal will allow all relevant data on utilities at a particular location to be collected through a single query, thus significantly reducing confusion due to incompatibil-ity between utility operators’ records. For UK stakeholders this will provide much improvement in the communica-tion of utility data. Furthermore, it should be noted that advancements in data communication also come from the data output of modern location equipment. For instance, through use of towed sensor arrays, as illustrated in Figure


2, 3D data are easily obtained, an example being given in Figure 10.

Figure 9. Visualizing 3D utility data using virtual reality.

Figure 10. An example of three-dimensional survey data.

That advancements in both sensor arrays and computer technology facilitate three-dimensional imaging is of par-ticular importance to MTU, as it intends to incorporate several different sensors into a towed unit that will radi-cally improve on the current best practice of sequential deployment of geophyical techniques by combining data, using data fusion techniques, from each location technol-ogy used such that the ‘best of all worlds’ scenario can be achieved. Also, through data fusion and integration of the positioning and mapping elements into the towed array as an automated process, it is anticipated that large areas will be traversed in a relatively short time. This will allow quick geophysical mapping of utilities with only minimal human intervention.

The MTU/SUE Goal: To make data both accessible and understandable to stakeholders and to ensure that those data are suitable for appropriate visualization that allows the third dimension to be included and eas-ily appreciated.

2.8 Managing and Communicating Risks Managing and communicating risks is essentially the whole purpose of SUE as a utility location practice. For

project managers, the time and financial risks associated with encountering unexpected utilities in excavations, or expected utilities in unexpected locations, are largely miti-gated as designs can be based on accurate position data in the X, Y and Z directions. In terms of highway users, the risks of encountering delays is significantly reduced, largely due to the ability of designers to anticipate, and so design out, conflicts between construction works and utili-ties. Also, the reduced potential for contractual over-run due to unexpected utilities means that inconvenience to road users, and the associated financial, social and envi-ronmental issues, are kept to the absolute minimum.

However, as a respondent to the MTU questionnaire stated 'What concerns me first is the risk to the operator/worker, secondly the cost of repair and lastly the inconve-nience to the utility company', which in simple terms means that we must ensure our principal priority is the health and safety of field workers. The difference between undertaking adequate SUE or leaving utility problems un-til they are encountered is illustrated by Figure 11: essen-tially, it means either being in control of utility planning or gambling with potentially serious hazards.

Figure 11. A possible dangerous scenario where a utility is either located properly (a), or located too late (b).

The MTU/SUE Goal: To allow all stakeholders to adequately predict, manage and mitigate safety, finan-cial, social and environmental risks associated with poorly recorded utility location data.

III. CONCLUSIONSAny problem that can be considered to have annual

social costs of the order of £5.5billion can only be de-scribed as serious. That much of this cost could be miti-gated through adequate utility location data only serves to make the issues surrounding that problem all the more pressing. Therefore, the work of the MTU project in the UK, and the SUE practice of the US, have been shown in an integrated context as an example of how best-practice in academia and industry can be brought together to pro-vide a holistic methodology suitable to significantly im-prove on current location technologies. The essential dif-ference between the US SUE and MTU approaches is that vacuum excavation for proving purposes is adopted under SUE’s highest level of service in which all utility services are guaranteed to be located, whereas MTU is seeking to detect and locate every utility service without excavation.


Nevertheless the two approaches have much to learn from each.

It has been shown that MTU will necessitate wide-ranging changes to utility management, from improved detection of utilities to improved detectability, and from significantly enhanced equipment to much improved loca-tion and data management systems. In so doing it provides a step change in our ability to manage buried utilities, whereas with each element used in isolation it could be considered only as an ad hoc improvement in the applica-tion of technology. When combined with SUE, the result-ing methodology can be considered holistic and fully en-compassing of the challenges faced by today’s utility man-agement stakeholders. Obviously, applying such a change in utility management practices will be a challenge in it-self. Therefore, the authors hope that interested stakehold-ers will take the opportunity to contact them through the online contact form at www.mappingtheunderworld.ac.uk. Only together can we improve utility location data and practices and move towards 100% detection rates.

In conclusion, the main goals of MTU covered in this paper, and so illustrating its vision, can be summarized as follows: Making geophysical utility location a transparent op-

eration where all stakeholders are aware of what can be achieved on a cost-benefit basis.

Ensuring that geophysical utility location can be planned and instigated based on the best possible planning data and using an optimum combination of a wide range of location techniques to complement GPR and operated using accredited operatives.

Ensuring that, in future, no newly installed buried utility is invisible to geophysical utility location de-vices.

Ensuring that advances in geophysical utility location are accompanied by adequate knowledge of the soil through which signals travel and that prior informa-tion on this can be obtained in order to allow im-proved planning and data interpretation.

Ensuring that records of utility locations are as accu-rate as possible, both during recording and in the fu-ture, and that these data are fully three-dimensional.

Making data both accessible and understandable to stakeholders and ensuring that those data are suitable for appropriate visualization that allows the third di-mension to be included and easily appreciated.

Enabling all stakeholders to adequately predict, man-age and mitigate safety, financial, social and environ-mental risks associated with poorly recorded utility location data.

ACKNOWLEDGMENTS The authors gratefully acknowledge the financial and other support provided by the UK’s Engineering and Phys-ical Sciences Research Council (EPSRC) and UK Water

Industry Research (UKWIR). The authors also gratefully acknowledge text and images provided by the US TBE Group and the University of Oxford for use in this paper.

REFERENCES[1] Burtwell, M., Faragher,, E., Neville, D., Overton, C.,

Rogers, C.D.F. and Woodward, T. “Locating Underground Plant and Equipment – Proposals for a Research Pro-gramme”, Report 03/WM/12/4, UK Water Industry Re-search Limited, London (2003).

[2] McMahon W, Burtwell MH and Evans M. “Minimising Street Works Disruption: The Real Costs of Street Works to the Utility Industry and Society”. UKWIR Report 05/WM/12/8. UK Water Industry Research, London (2005).

[3] Rogers, C.D.F., Chapman, D.N. and Metje, N. “Mapping the Underworld - UK Utilities Mapping”, Proc. of 11th Int. Conf. on Ground Probing Radar (GPR2006), Columbus, Ohio, USA, 19-22 June (2006).

[4] Rogers, C.D.F., Chapman, D.N. and Karri, R.S. “UK Engi-neering Network in Trenchless Technology (NETTWORK)”, Proc. of Int. Conf. on Plastic Pipes XII, Milan, Italy, April (2004).

[5] Thomas AM, Metje N, Rogers CDF and Chapman DN "Underground utility infrastructure: improving sustainabil-ity through improved detectability - the stakeholders' per-spective". Proc. of 24th International No-Dig Conference and Exhibition, Brisbane, Australia, 29th October-2nd No-vember (2006) (CD ROM).

[6] Rogers, C.D.F., Zembillas, N., Thomas, A.M., Metje, N. and Chapman, D.N. "Mapping the Underworld - Enhancing Subsurface Utility Engineering Performance", Transporta-tion Research Board 87th Annual meeting, Washington D.C., January 13 – 17 (2008).

[7] Hunt, D.V.L. and Rogers, C.D.F. “Barriers to sustainable infrastructure in urban regeneration”. Proceedings of the Institution of Civil Engineers: Engineering Sustainability, 158, No. 2, 67-81 (2005).

[8] Craig, R.F., “Soil Mechanics - Sixth Edition”, E & FN Spon, London (1997).

[9] Thomas, A.M., Yelf, R., Gunn, D.A., Self, S., Chapman, D.N., Rogers, C.D.F. and Metje, N., “The Role of Geotech-nical Engineering for Informed GPR Planning and Interpre-tation in Fine-Grained Soils”, 12th International Confer-ence on Ground Penetrating Radar, Birmingham, UK, June 16-19 (2008).

[10] Thomas AM, Metje N, Rogers CDF and Chapman DN., "Soil Electromagnetic Mapping for Enhanced GPR Utility Location”. Proc. of 25th International No-Dig Conference and Exhibition, Rome, Italy, 9th to 12th September (2007) (CD ROM).


Documents

Proceedings Template - WORD€¦ · Web viewAlternatively, the use of multi-utility tunnels proposed by some researchers [7] would eliminate the need for detection equipment in