Relationships and Responsibilities Frequently, projects for which ground improvement may be applicable are structured to take advantage of the specialized engineering and design knowledge of Ground Improvement Contractors. To take advantage of the specialty contractor’s knowledge, the ground improvement scope of work is engineered and designed by the specialty contractor. This “design-build” framework blurs the boundaries of design responsibility between the Owner’s engineer/designer and the Contractor. Consequently, a well-written ground improvement specification will clearly establish these boundaries. Of particular importance is defining who is responsible for selecting/determining the soil properties at bid time. Will data be provided in the form of a data report or will contractually-defined soil properties to be used by all ground improvement designers be specified? If soil parameters are not explicitly provided in the specification, the characterization of the soil properties and the assessment of the likelihood of a design event (e.g., earthquake, flood, etc.) by bidders may result in substantially different approaches, different levels of ground improvement to be performed, and associated variation in costs. It is important that the drafter of the specification clearly appreciate that these parameters characterize the subsurface conditions of the Owner’s property and will be used to develop ground improvement programs to improve the Owner’s property, for the Owner’s benefit. If soil properties and parameters are not explicitly provided, the author of the specification must ensure the Owner is comfortable in accepting a design based on less conservative parameters and/or design conditions in the interest of saving time or money. The specification should define if the Ground Improvement Contractor’s preliminary design is to be submitted with the bids. This may allow the Owner and his/her engineering team to determine the extent to which the low bidder has or has not met the minimum specified design requirements. If the preliminary ground improvement design is to be submitted as part of a bid package, it must be established how the Ground Improvement Contractor’s exclusive design will be protected during scope reviews/ comparisons, in the event all bids are rejected, or if all bids are made public. The intellectual property of each of the specialty contractors is valuable and must be recognized and protected. The specification must define who is responsible for the review and acceptance of the final design. The Owner has three possible roles: 1. The Owner makes no technical review of the Contractor’s design and the contractor is responsible for code compliance and relevant agency reviews and approvals. 2. The Owner reviews the contractor’s design for compliance with the requirements of the specifications but the contractor is responsible for code compliance and relevant agency reviews and approvals. 3. The Owner is responsible for review for specification compliance and design intent and is responsible for agency review, approval and issuance of permits. 86 • DEEP FOUNDATIONS • MAR/APR 2016 In all cases, the Ground Improvement Contractor is to provide a design that intends to meet the requirements of the specifications and/or the requirements of the permitting Agency. The author of the specification and the Owner should determine if a peer review of the Contractor’s design is required, depending on the complexity of the design and the nature of the project. Finally, the specification should address the relationship not only between the Ground Improvement Contractor and the Owner/Designer, but also between the Ground Improvement Contractor and the Prime Contractor/Construction Manager and other parties to the project. Geotechnical Information The specification must adequately convey all available project information to be used for preparation of proposals and for ground improvement design. It must also define the form in which the information will be provided. For example, will samples be stored and made available for inspection by the bidders along with the exploration logs? Will digital files for CPT soundings (as an example) be made available to the bidders? Additionally, is a site visit planned or required? Do opportunities exist for the contractor to conduct independent investigations? At a minimum, the information provided to potential Ground Improvement Contractors must include: 1) The geotechnical report. 2) Exploration logs. 3) Available laboratory and in situ testing results. 4) The project datum elevation and coordinate system. 5) Existing and planned grades and slope geometries. 6) Existing and planned utilities. 7) Available information on the groundwater regime, along with existing and planned surface drainage features. 8) Available information on the site history: a) What grade changes have been made and when? b) Has the site experienced quarrying, surface mining or underground mining? c) Is there history or documentation of karstic activity or solution features or pinnacled rock? d) What structures existed, where and when? e) Did previous structures experience any distress associated with geotechnical conditions (e.g., excessive settlement, differential settlement, etc.)? 9) Existing and/or potential sources of contamination (soil, ground water, etc.). 10) The planned construction sequence. Additional guidance can be found in GeoConstructability – An Owner’s Guide to Obtaining Essential Geotechnical Information for Construction, Report of the Geotechnical Constructability Task Force, Geo-Institute of ASCE, American Society of Civil Engineers, 2011.
