Tunnel projects are linear and can extend for miles We prepare a Geotechnical Baseline Report to • Describe the anticipated subsurface conditions and how they will influence the construction • Describe how they influenced the design • Identify the key subsurface risks on the project • Describe how those risks are allocated between the The use of a GBR must be associated with express contract provisions to deal with changed conditions, or the parties will face an uncertain recourse to the governing law of the contract to resolve disputes, defeating the purpose of defining both what is considered ‘unforeseeable’ and the remedies available under the contract. Introduction The Big Sand Wash Reservoir Enlargement project forms a major part of the Lake Fork Section 203(a) Uinta Basin Replacement Project. Pre-bid reports prepared for contractors preceded the advent of GBRs. in case of disputes. Report, the Environmental Baseline Report, or the Geotechnical & Environmental Data Report as set forth in Section 5.7.2 or a foundation type for a Structure that is substantially different from the foundation type identified in TR Appendix S for When the GBR is included in the contract, becoming the contractually accepted interpretation of the site data, the baselines serve as contractual references to establish where conditions encountered during construction that are materially more adverse, onerous and time consuming, may be considered as ‘unforeseen’. It is difficult to write an appropriate GBR linked with DSC that define in clear terms those circumstances that ought to be foreseen and provide a practical mechanism to measure differences, meting out the relevant remedies. %PDF-1.5 %���� The Geotechnical Baseline Report (GBR)is intended to form the basis for establishing the ground related risks in the design and construction for the execution of Underground Works, and as such is critical in providing a balanced allocation of risk between the Parties. Submitted herewith is the Phase 1 Geotechnical Baseline Report for the proposed improvements to LBJ Freeway. The comments in this report relate to those alignments. GEOTECHNICAL INVESTIGATION CITY OF HOUSTON SURFACE WATER TRANSMISSION PROGRAM CONTRACT 74A-1 WATERLINE COH WBS NO. General Planning Consultant Six Managed by HDR The GBR ‘carries clear definition of risks and their allocations’ and ‘contains an effective means to settle disputes as risks materialise’ (H. Tang, 2001). Final Geotechnical Baseline Report November 28, 2018. Finally, the GBR can make the parties lay out clear conditions that prevent ‘the “pinch points” that provide fertile ground for the growth of legal risk …’ (Capper, 1994). �n��V�i�b��w�ݬ���z�3p�e��t��Z�^�ų�,�q�m��k�}�tJ�����)gs�`��ށ{o���D*��̮�D�eS���y�?˰�t�s� ������d֖�:�*��խ7��n��C��>q�9�r�*7�zWY�p��������+�Yݕ�,��-����I��c��G\�R���Xc/%�A��w�Zq���:�H��2��$I�����%#h)=�Y�@g��Bv/x_������~�����B��".zL�9Ƃ�4 ��|�y8��{b$ 0�W*@��|�z��#�HH4�+�B�I��د@�;G�p��x�@;t���e. The GBR included characterization of the geotechnical parameters and ��%l8:X�; ���Q٨,$���A��@�@F�� ��|���3g&!�b�z&w�g� ۼ�$l��yإ�jf0��z�"��H�d`�� �� February 26, 2020 . The description should be detailed enough to encompass the range of conditions that might occur in a project. A similar definition is included in A Code of Practice for Risk Management of Tunnel Works, prepared by ITIG in May 2012, which used the term of ‘Ground Reference Conditions’. Dallas, Texas . Contract Documentation (as well as subcontract documentation for Tunnel Works as appropriate) shall include Ground Reference Conditions or Geotechnical Baseline Conditions prepared by the Client (or prepared on his behalf) or shall require each tenderer to submit with their tender their own assessment of Ground Reference Conditions or Geotechnical Baseline Conditions, the … Final Geotechnical Baseline Report 1.0 - Introduction REGIONAL CONNECTOR TRANSIT CORRIDOR PROJECT April 20, 2012 Page 2 1.2 Scope of the Geotechnical Baseline Report This GBR pertains to the underground portions of the RCTC project. A potential weakness of the GBR lies in this very point. A connected purpose of GBR is risk management during contract implementation, since it can be used as the starting point to prepare a risk assessment and management plan as far as geotechnical conditions are concerned. Description (cont’d) • Contractor proposed a self-built open face This report details proposed work for the Waller Creek inlet tunnel, inlet shaft, and debris channel. California High-Speed Rail Authority, 2016, San Jose to Merced Project Section, Draft Preliminary Geotechnical Data Report for Tunnel Subsection, September. The Ground Risk and Geotechnical Baseline Reports: A Legal Perspective, A Unified Industry-Wide Voice for the Future of Tunneling, Proving Ground: Twin Bores Provide Perfect Test Bed for BTrenchless, NUCA Calls On New Administration To Keep Its Focus On Infrastructure, Hobas Pipe USA Supports Critical San Antonio Infrastructure Project, NHEO Institute, Bechtel Partner To Advance Innovative Safety Practices, Bouygues-Barletta JV to Build Pawtucket Tunnel. Revision A . 2 Page 6, Field Trip Guide "Tunneling Through a Miocene Plate Boundary" by Chris Risden and Ivy Morrison. GE‐004 Tunnel Soil Interpretative Report ... superseded by the Geotechnical Baseline Report (GBR). The contents of the GBR should be balanced and realistic, since ‘overly conservative baselines for items such as obstructions (…) can result in overly conservative and costly bids’ (SME, 2008). The use of Geotechnical Baseline Reports (GBRs) for contractually de ning anticipated ground conditions has become a widely accepted practice in the tunneling industry. Tunnelling in Difficult Ground: How the Geotechnical Baseline Report Helps R. Perlo, M. Swales and T. Kane More details are available in the paper presented by the authors at the June 2017 RETC conference in … RELATED: Risk Management Professionals Convene in DC. Technical Specifications Report. the project geotechnical engineer and prepared the Geotechnical Data Report and Geotechnical Baseline Report. foundations, utilities or other geotechnical hazards Engineering Group of the Geological Society 15th September 2009 Example of a baseline statement (1) • Tunnel in glacial till • Boulders of rock are to be anticipated • Estimated 100 to 300 boulders • Set baseline at 300 boulders – the risk of unforeseen ground conditions is removed S-000900-0109-3 HOUSTON, TEXAS 1.0 INTRODUCTION 1.1 General The report submitted herein presents the results of Aviles Engineering Corporation’s (AEC) geotechnical As such, it is an effective tool for the management of differing ground conditions, provided that the GBR is incorporated in the contract as a warranty and without disclaimers. Thank you and be well. Geotechnical Baseline Report . The above definitions provide the synthesis of the purposes of GBR, i.e. Therefore, the first question is what conditions are expressly or impliedly foreseen under the contract. Debunking the baseline conundrum Dec 2015 Dr. Peter J. Tarkoy, USA. 12374.001 -4- 2.0 GEOTECHNI CAL CONDITIONS Presented below are “baseline” site geologic/geotechnical conditions based on review of pertinent literature and the site-specific field exploration (Leighton, 2020). What is foreseen in the contract must be included in the price, but the obligations under changed conditions depend on the contract stipulations and the law governing the contract. �U�{�!�� ���� In addition to the reservoir enlargement, the Then, the contractor does not need to be predictive and include further contingencies in his price beyond the limit of the conditions defined in the contract baseline. That is the reason why ground conditions are best expressed in terms of characterization and probability. Historical Perspective Assessing Geotechnical Risk Risk Sharing Philosophy GBR Fundamentals Case Histories 2 ... borings and profile showing tunnel outline • Interpretive Geotechnical Report in the Contract • Over-consolidated clays - the Cretaceous Patapsco formation. If the contractor comes across a more adverse condition If a ground conditions report is not expressly incorporated in the contract, it is not considered a term of the contract on which rights and obligations are measurable by reference to it, but ‘would require an unambiguous wording to give rise to such a result’ and ‘it does not contain any statement sufficiently definite and unqualified to amount to a representation upon which [the parties](…) could reasonably have relied.’ Under the circumstances, the stringent performance requirements of Thorn v London Corporation apply to the contractor. tunnel and facilitate installation and future maintenance of the pipeline. Road tunnel, highway tunnel, geotechnical investigation, geotechnical baseline report, cut-and-cover tunnel, drill-and-blast, mined tunnel, bored tunnel, rock tunneling, soft ground tunneling, sequential excavation method (SEM), immersed tunnel, jacked box tunnel, seismic consideration, 100 pp. Specific details of the current vertical alignments are shown on Geological Section Drawings 252-255, 258-262 and 326-337 which are contained in Appendix B. Geotechnical Baseline Conditions or Report (GBR) is a single ‘contract document containing measurable contractual descriptions of the geotechnical conditions to be anticipated (…) during construction’, (D. Page, 2009). Disputes Review Board . Shield Tunnel Boring Machine (TBM), highlighting the use of detailed geotechnical characterisation as the primary driver for offsetting risk from unforeseen or changing ground conditions during tunnelling. Copyright 2019 Benjamin Media, Inc.     |. 0064‐M06‐032 Virginia Department of Transportation. Finally, since ‘for the success of any construction contract the risk must be acknowledged and clearly allocated’ (CIRIA, 1983), the GBR provides an answer as to what ground conditions are allocated to the contractor, thus contributing to the successful management of a contract. When the parameters of ground conditions that ought to be foreseen cannot be reasonably obtained by the contractor through his site investigations, the information provided by the employer at tender stage becomes essential to define what is foreseeable under the contract, as shown below. Geotechnical Baseline Reports (GBRs), John was co-author of many of the first GBRs written for underground projects in Ontario. 1.1 General. Independent geotechnical consultants have prepared these (pre-bid) reports for the last 70 years or more. Properly drafted GBRs reduce construction costs and set clear terms between the parties in the event of more adverse ground conditions, thus contributing to dispute avoidance. Over cautiously drafted baselines may cause the Contractor to bear the total responsibility of the ground risk, resulting in a higher bidding price. 2 Page 6, Field Trip Guide "Tunneling Through a Miocene Plate Boundary" by Chris Risden and Ivy Morrison. Escrow Bid Documentation . For example, geotechnical investigations may include many reports that may be difficult to integrate in a single interpretative work. ... Geotechnical Baseline Report. Conversely, site conditions differing from those considered in the GBR are deemed to be ‘unforeseen’ under the contract and ae carried out at the employer’s risk. advance rate of excavation, as they may ambiguous and lead to discussions. If the method of work is linked to the baseline conditions established in the contract, it becomes evident when changed site conditions lead the parties into a variation. Figure 1 shows the approximate location of the crossing. 0 ... Geotechnical Data Report. As described in more detail in the following sections, the underground portions of the project include the bored 1756 0 obj <> endobj The Joint Code of Practice for Risk Management of Tunnel Works (2003) defines Geotechnical Baseline Conditions as follows: Definitive statements about (…) the ground (…) and groundwater together with geotechnical properties of the ground which serve as the basis for construction Contract tendering purposes and for subsequent application of the contract with respect to the conditions actually encountered during Tunnel Works. Geotechnical Baseline Report for 20% Design . 1764 0 obj <>/Filter/FlateDecode/ID[<59B38C246B2FF440950F57BF29236683><1DB92ECBFE83A2449A4790C454B598D6>]/Index[1756 16]/Info 1755 0 R/Length 58/Prev 376390/Root 1757 0 R/Size 1772/Type/XRef/W[1 2 1]>>stream the site data to be considered and relied upon, a measure of the risks to be included in the contract price, the watershed for risk allocation under the contract, and the basic list of hazards to be considered for ground risk management. This report includes: w��Y. The rationale of this common law principle lies in the contract since, where the contractor has undertaken to complete a work and comply with contract drawings and specifications he bears the cost of performing the promises, irrespective of changed conditions, without entitlement to variations. For instance, in tunneling, this document could identify the expected geotechnical classification, the method of classification, and the distribution of the types of rock classes along the tunnel profile. Furthermore, an undefined scope for ground conditions that are to be expected under the contract is an open door to disputes, and the remedy is finding a way to define the parameters of what is or ought to be included in the contract price. In fact GBR should be included as a representation, and not be merely provided ‘for information’. This would create fertile ground for denial of responsibility and disputes, especially when there is an expensive bill to pay as a consequence of adverse ground conditions. The court upheld the principle of certainty of price and performance. Another controversial point is when the DSC includes terms that are related to performance, e.g. Eugenio Zoppis is a PhD Researcher at King’s College in London. Tunnel projects are linear and can extend for miles We prepare a Geotechnical Baseline Report to • Describe the anticipated subsurface conditions and how they will influence the construction • Describe how they influenced the design • Identify the key subsurface risks on the project • Describe how those risks are allocated between the Geotechnical Baseline Report Table of Contents WESTSIDE SUBWAY EXTENSION PROJECT A mendment 3 October 15, 2013 Page i May 22, 2013 Table of Contents In Thorn v London Corporation, the court dismissed the contractor’s allegation that there would be an implied warranty as to plans and specifications providing the use of caissons that were not buildable due to adverse ground conditions, as ‘although it was the engineer who suggested building those caissons, the builder promised he would’. When the GBR is part of the contract, it sets the range of adverse physical ground conditions that ought to be provided for and included in the contract price. During construction, the baseline may be compared with actual conditions, in order to determine if and how much these circumstances are more unfavorable than expected, and to evaluate the appropriate compensation. If the contractor’s concern is that the employer may disclose this information to other tenderers, a means to dispel it is that of depositing the bidding documents as Escrow Bidding Documents, or EBD to be used only when necessary, e.g. Road tunnel, highway tunnel, geotechnical investigation, geotechnical baseline report, cut-and-cover tunnel, drill-and-blast, mined tunnel, bored tunnel, rock tunneling, soft ground tunneling, sequential excavation method (SEM), immersed tunnel, jacked box tunnel, seismic consideration, INTRODUCTIONIn recent years, the use of geotechnical baseline reports (GBRs) on microtunneling projects has become increasingly popular. As the contract progress unfolds, the parties can measure the difference between the reference conditions included in the GBR and the actual conditions met on the ground. h��TMo�0�+�,($Y�X�`��EZ�%F;�U���#eYs� �m$Q��IG�L��2M��ܯ91���P��R)���]��=����m���)�}9Zv��d�;����墲[;O�y�/��wϮ��������zk�{SF&���/�=�̮ On the other hand, a vague or broad description of ground conditions would not eliminate uncertainties on risk allocation but, after any event, it would leave room for its interpretation with inevitable hindsight knowledge. 7 8 Underground “Facts of Life” means, methods, and . ... volume of soil excavated along the length of the tunnel alignment will consist of cobbles and boulders." Next, we turn our attention to the fossils recovered during tunnel construction. This information is coupled with construction methods and geology of the construction site, as well as considerations for construction. GEOTECHNICAL BASELINE REPORT FOR OUTLET WORKS CVO/BSW GEOTECHNICAL BASELINE REPORT.DOC 1-1 1. Differing Site Conditions Clause . In reading this report it is important to remember that in all of the major Crossrail Civil Engineering contracts Contractor design activities were limited to temporary works only. Although originally developed for use on large diameter tunneling projects, GBRs have been implemented on a number of microtunneling projects. A geotechnical investigation program for a tunnel project must use appropriate means and methods to obtain necessary characteristics and properties as basis for planning, design 1 Page 69, Caldecott Improvement Project: Geotechnical Baseline Report, prepared by Jacobs Associates, June 2009. Bill Wang (Senior Geotechnical Engineer – Golder Associates), who assisted with preparation the report titled, West Gate Tunnel Project Technical Report D, Appendix A – Ground Movement Modelling Prediction – Tunnels and Portals 1521107-211-Rev0. Through his career John has been retained to undertake forensic investigations of geotechnical failures and expert reviews of underground construction claims on more than 50 projects. Above all, since GBR is the formal representation of the ground conditions on which the contract price is founded, it should not be manipulated in any direction, to avoid allegations of misstatement or misrepresentation. Submitted herewith is the Phase 1 Geotechnical Baseline Report for the proposed improvements to LBJ Freeway. This paper intends to demonstrate that the incorporation of ground baseline conditions/report in contracts is an effective tool for managing the ground risk in construction projects, for reducing costs and for dispute prevention or settlement. INTRODUCTIONIn recent years, the use of geotechnical baseline reports (GBRs) on microtunneling projects has become increasingly popular. Tunnel projects are linear and can extend for miles . Another good reason to give a balanced position to the GBR is that of motivating each party to resolve the difficulties that eventuate during construction within their capability and in the interest of the project that should be completed on time and within the budget. endstream endobj 1757 0 obj <>/Metadata 168 0 R/OCProperties<>/OCGs[1765 0 R]>>/Outlines 243 0 R/PageLayout/SinglePage/Pages 1747 0 R/StructTreeRoot 320 0 R/Type/Catalog>> endobj 1758 0 obj <>/ExtGState<>/Font<>/XObject<>>>/Rotate 0/StructParents 0/Tabs/S/Type/Page>> endobj 1759 0 obj <>stream However, this is the very reason for putting the common seal to a single GBR, warranted and relied upon by the parties. • Preparation of a Geotechnical Baseline Report (GBR) to define the baseline conditions on which contractors will base their bids and select their means, methods and … As described in more detail in the following sections, the underground portions of the project include the bored The actual conditions then encountered are measured against this baseline. Please subscribe below to ensure delivery of future digital editions. Next, we turn our attention to the fossils recovered during tunnel construction. 1 Introduction and background 1.1 Introduction This document sets out to record Crossrail’s experience of the use of Geotechnical Baseline Reports (GBRs) in its construction contracts. Geotechnical Baseline Report Revised August 28, 2020 Murrieta Road Transmission Pipeline Project No. A Geotechnical Baseline Report (GBR) is a document included in the construction contract, which provides the parties to the contract with a mutual understanding of the subsurface site conditions (the baseline). As such, those conditions should be considered as the basis, or the baseline, for risk evaluation and pricing. Disputes Review Board . In the case Mitsui v Attorney General of Hong Kong under a remeasurement contract where actual quantities were in different proportions from those estimated in the B.o.Q, the judge quoted the definition of ‘variation’ from Hudson’s Building and Engineering Contracts (10th edition) at p. 506 as follows: ‘Works which are not expressly or impliedly included in the original contract and, therefore, are not included in the contract price, are generally termed variations, …’ [emphasis added]. %%EOF The BNSF railroadcrossing and the associated launch and reception pit and shafts arethe subject of this Geotechnical Baseline Report (GBR). By contrast, the GBR is a document that is known by all and, when used at the bidding stage, places all contenders on level ground, promoting a conscious and keen tender pricing. GPC6, C-2012668-02, Task Order #39 Dallas CBD Second Light Rail Alignment (D2 Subway) Concept Design . Present the results of geotechnical investigations conducted for the project in a factual manner. In conclusion, since ‘it is legitimate, and commercially desirable, that both parties should be able to measure the risk, and agree the price on the basis of the warranties which have been given and accepted’, data and reports on ground conditions may be considered a term or a warranty when they are expressly incorporated in the contract, as long as there is no uncertain language and there are no waivers or disclaimers. The Geotechnical Baseline Report (GBR) is a statement representing the known ground conditions in a project site. The GBR should take a practical approach in defining the site conditions; it should focus not only on the ground but also on the method of work. The associated launch and reception pit and shafts arethe subject of this Geotechnical Baseline for. Of many of the ground risk, resulting in a project site ( Appendix a ) seal to a Interpretative... 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