Twenty-story High Rise Medical Research Center
Massachusetts
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 Development of 20-story high-rise research center with up to six levels of underground parking in a congested urban setting has presented SHA with numerous geotechnical engineering and geoenvironmental challenges. Solutions have included reinforced concrete diaphragm (slurry) walls to provide permanent wall foundations and temporary excavation support, heavily loaded spread footings bearing on the dense glacial till, permanent groundwater control, protection of numerous adjacent utilities and geotechnical instrumentation to monitor soil and wall movements and groundwater levels during construction.
Photo courtesy of William A. Berry, Inc.; Tsoi, Kobus & Assoc., Inc. and Neoscape.
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Fast-tracked Contaminated Site Development
BJs Wholesale Club - Tilton, New Hampshire
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 SHA provided complete geotechnical and geoenvironmental services during design and construction of this fast-tracked project at the site of a former 40-year old asphalt plant built in a wetland and with petroleum soil and groundwater contamination issues. Geotechnical design challenges included determining extent of compressible organic soils buried beneath historic fill soils located in proposed building areas; improvement/densification of thick existing uncontrolled fill soils and waste asphalt so that they could support buildings, roadways and parking areas; and, sequential free-product removal followed by construction phase dewatering to allow identification and removal of buried organic soils. Further complicating the project was the need to find, site and permit a water supply well within the constrained 5-acre site.
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Contaminated Site Redevelopment
Retail Store - Quincy, Massachusetts
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 SHA provided geotechnical and geoenvironmental services for redevelopment of a site for a new 119,000 sf retail store. Key project components included: design and construction of a shallow structural mat foundation to allow for construction of the building over existing fill material and old building foundations left in-place, and to reduce the client's liability associated with excavation and disposal of contaminated soil and groundwater. The project involved the installation of utilities through heavily contaminated areas below the groundwater table, design of a subslab ventilation system with geomembrane beneath the building slab plus negotiation and coordination with the potentially responsible party.
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Site Development in Unsuitable Bearing Soils
Best Buy - Dedham, Massachusetts
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 This 48,000 sf retail store was constructed in a historically-filled wetland using concrete-filled steel pipe piles and a structural concrete slab in order to transfer building loads through thick unsuitable fill, organic peat and very soft clay down to glacial till at depths of 75 feet or greater. SHA performed detailed feasibility studies to assess various foundation options; however, due to time constraints for a fast-track construction schedule the pile foundation alternative was most viable. SHA saved significant time and money by conducting dynamic pile load tests during production pile driving using a pile driving analyzer (PDA). SHA provided geotechnical design services, oversight of dynamic pile load tests and pile driving inspection services.
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Earth Dam Design and Construction
Maplewood Development - Nashua, New Hampshire
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 This project involved design, permitting and construction of a new earth dam approximately 500 feet long and 16 feet high as part of a stormwater detention system for this 241-lot residential development. The design included a low permeability compacted soil core and pond liner to control seepage through the dam and extend seepage paths to reduce upward seepage pressures to acceptable levels. SHA provided geotechnical design services, prepared the application to NHDES for a Permit to Construct a Dam, and provided quality control field monitoring and testing during dam construction.
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Six-story Office Building
Waltham, Massachusetts
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Geotechnical and geoenvironmental services were provided for design of a six-story class A office building with four levels of below grade parking for this high profile site. Significant geotechnical issues included major blasting and rock excavation in a highly developed area that needed to be coordinated with assessing and remediating soil and groundwater contamination issues.
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Pile Foundation Design
776 Beacon Street, Newton, Massachusetts
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 SHA performed a subsurface exploration program and provided design phase geotechnical engineering services for this two-story retail building. Subsurface conditions in the building area encountered 15 feet of loose and petroleum contaminated fill, overlying soft clayey silt overlying glacial till. SHA provided foundation alternatives and comparative cost estimates. The recommended foundation system included 12-inch diameter Pressure Injected Footings (PIFs) with an allowable load of 40 tons installed to a depth of 25 feet in the top of the glacial till soils. SHA prepared technical specifications for the PIF installation contract; provided technical oversight, monitored and logged PIF installation for compliance with the project specifications and the Massachusetts Building Code; conducted a preconstruction videotape survey of adjacent structures; and, conducted vibration monitoring during the PIF installation work.
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Main Access Roadway Widening
New Hampshire International Speedway - Loudon, New Hampshire
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 Expansion of the raceway required a widening of the main roadway and installation of a 48" diameter culvert over an area of highly compressible organic soils more than 15 feet thick. Potential failure of the culvert due to anticipated excessive settlement resulting from the weight of the additional roadway fill required SHA to design a pre-loading scheme to surcharge the organic soils with fill soils and then monitor the settlement rate. The project was successfully completed within a tight time schedule.
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Site Redevelopment
Proposed Retail Store - South Burlington, Vermont
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 SHA provided design phase geotechnical engineering and environmental site assessment services for this proposed 121,300 square foot retail building. Explorations indicated that the site is underlain by 30 to 50 feet of soft clay. To avoid damaging differential settlements across the building area, it was necessary to design a surcharge program to preload the appropriate portions of the site area together with wick drains to accelerate the settlement process. Geogrid reinforcement has been added to slopes and the fill progression has been divided into stages to maintain the stability of the slopes during and after construction. Instrumentation will be installed to monitor settlement and the stability of the slopes during construction.
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Characterization and Remediation of Former Plating Facility, and Geotechnical Design Services
Somerville, Massachusetts
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A former plating facility was being considered for commercial redevelopment. Site soils contained elevated concentrations of chromium, cyanide, nickel, lead and other inorganics, as well as polynuclear aromatic hydrocarbons free product oil and volatile organic compounds. Groundwater contained elevated concentrations of chromium and nickel. Groundwater chemistry was complicated by high pH (up to 12). Following the completion of the remedial effort, SHA was requested by the new owner and proponent to provide geotechnical design services to the project team. The project will involve construction of a very large underground parking garage below two mixed-use buildings, two other free-standing buildings, and an above ground parking structure. All of the structures will be pile supported. Given the nature of the residual soils at the site, a detailed soil management plan will also be required during construction.
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