Bridge over the Androscoggin River, Bethel, Maine
Status: Construction Completed 2005
SA evaluated shore (abutment) and river (pier) geotechnical conditions and designed pile foundations for this 400-foot, 3-span river crossing bridge owned by the City of Bethel, and funded by Maine Department of Transportation, Multimodal Division. SA evaluated subsurface conditions at river piers using a barge-support drill rig and performed borings for the new abutments by truck-mounted drill rig. Using the data obtained, and AASHTO guidelines, SA designed foundations for this large bridge traversing the Androscoggin - one of Maine’s most destructive rivers - to resist scour and large ice forces. These issues governed design and construction recommendations. The Bridge is adjacent the existing US Route 2 Bridge and carries an existing recreation (bicycle, pedestrian and snowmobile) trail over the Androscoggin River at this dangerous location.
MassHighway Bridge Over Stillwater River, Sterling, Massachusetts
Status: In design
The Massachusetts Highway Department is evaluating and replacing the bridge carrying Muddy Pond Road over the Stillwater River. Home of a gaging station operated by the United States Geological Survey, the bridge deck will be widened and the deck will be replaced to accommodate current standards. Stephens Associates was retained by the prime consultant to perform a geotechnical and seismic evaluation of the existing abutments and provide geotechnical design of new integral abutments by MassHighway and AASHTO Standards. View the bridge and check out USGS water flow data at: http://ma.water.usgs.gov/projects/Stillwater/stillwater.htm
New Radar Air Traffic Control Tower/Facility, Brunswick Naval Air Station, Brunswick, Maine
Status: Under construction
SA performed preliminary geotechnical engineering in preparation of the design-build bid package for the new 7-story radar air traffic control facility for the United States Navy.
Dam Engineering, Greenough Pond Dam, Carlisle, Massachusetts
Status: In design
The town of Carlisle has retained SA to evaluate the existing Greenough Dam, a 400-foot-long embankment dam impounding Greenough Pond. Massachusetts Department of Environmental Management classifies the Dam as Intermediate in size. SA will inspect and evaluate the Dam, design repairs and prepare an Operation and Maintenance Plan when repairs are completed. Construction will commence in 2004.
MBTA Copley Station Renovations, Boston Massachusetts
Status: Final design
The Massachusetts Bay Transportation Authority is updating its Stations to comply with the requirements of the Americans with Disabilities Act (ADA). SA was retained to provide geotechnical engineering of foundations, excavation support and dewatering recommendations for installation of elevators and associated below-grade facilities near movement-sensitive historic structures such as the Boston Public Library and Old South Church. Station renovations are estimated at to be about $8M.
Brockton Area Transit Authority (BAT) Parking Garage, Brockton, Massachusetts
Status: Under construction
The Brockton Area Transit Authority is increasing its parking capacity by constructing a new parking Garage. The new garage will be about one acre in footprint, and is being designed for up to 3 stories of parking. SA is performing geotechnical engineering for the new garage, and associated structures.
MASSPORT Logan Express Parking Garage, Framingham, Massachusetts
Status: In design
The Massachusetts Port Authority (MASSPORT) has run out of parking space during weekly peak usage at the Logan Express Site in Framingham, Massachusetts. The solution to the problem is construction of a new parking garage. The new structure will be 4-stories high and about 2-acres in footprint area, and capable of parking about 1200 cars. The construction will consist of precast concrete. Construction costs are estimated to be more than $15M. The site soils include un-engineered fills and loose, liquefaction-susceptible natural sands, as well as buried wood and other organics. Stephens Associates Consulting Engineers (SA) was retained to provide geotechnical design. Because of the poor site soils and the heavy loads imposed by the precast concrete and cars, SA recommended pile foundations.
Livingston Street Reconstruction Research, Tewksbury, Massachusetts
Status: Underway
Stephens Associates Consulting Engineers (SA) was retained by the civil engineer, at the request of the Town of Tewksbury, to provide a value-engineered design for the first-ever use of tire shreds as lightweight fill in a roadway embankment in Massachusetts. At the request of the Massachusetts Highway Department (MassHighway), SA submitted a separate proposal, and was awarded the funding, for the study of pre- and post-construction performance of the roadway embankment reconstructed using tire shreds. Research objectives include predicting and measuring pre- and post-construction behavior of organic foundation soils, embankment materials (soil and tire shred fills) and pavement. The project includes an exhaustive literature search, extensive exploration, laboratory testing and geotechnical instrumentation plans, geotechnical instrument installation (e.g. vibrating wire piezometers, multiple (4) position Borros Point rod extensometers, inclinometers, etc.), detailed finite element modeling, and roadway performance monitoring over 2 years. As a requirement for the funding, SA will use the research to prepare Standard Design Details and Construction Specifications for the use of shredded scrap tires as lightweight fill on future MassHighway projects.
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Livingston Street Reconstruction Design, Tewksbury, Massachusetts
Status: Construction completed 2002
Stephens Associates Consulting Engineers (SA) was retained by the civil engineer, at the request of the Town of Tewksbury, to provide a value-engineered design for the first-ever use of tire shreds as lightweight fill in a roadway embankment in Massachusetts. The Town has experienced problems with Livingston Street for more than 40 years. The roadway traverses a wetland underlain by organic silt and peat. It was reconstructed in the late 1970’s, but the Town has applied 7 to 8 overlays to various portions of this section since then. Significant portions of the existing roadway embankment are petroleum-contaminated. SA recommended the use of tire shreds as lightweight roadway embankment fill and provided environmental guidance in addressing the petroleum contamination. SA designed the tire-shred-fill embankment. The Roadway reconstruction was funded under Massachusetts Highway Department (MassHighway) Chapter 90. The Town received approval from MassHighway to use those funds with this unique solution. The Contractor’s bid for the total reconstruction was about $500,000. The savings to the Town by using the tire shreds as lightweight fill are estimated to be more than $220,000. The construction provided for the beneficial use of about 200,000 scrap tires.
[Click for Press Release]
MASSPORT Airfield Lighting Vault, Logan International Airport, East Boston, Massachusetts
Status: Construction completed 2002
The Massachusetts Port Authority (MASSPORT) needed additional capacity for electrical supply for Airport field lighting at Logan International Airport. The solution to the problem is a large addition to the existing field lighting vault. The new structure will be about 60 percent as large as the existing field lighting vault, and will cost more than $2M to construct. The site soils include un-engineered hydraulic fills, loose, liquefaction-susceptible natural sands, organics including silt and peat, as well as compressible Boston Blue Clay. Stephens Associates Consulting Engineers (SA) was retained to provide geotechnical design and structural design of foundations. Because of the poor site soils and the fact that the existing structure is pile supported, the foundation design called for pile foundations.
Northeast Refrigerated Distributing, Tewksbury, Massachusetts
Status: Construction completed 2001
The Northeast Refrigerated Distributing Company needed a new, $3.6M, 35,000 sf, 40-foot-high refrigerated warehouse for storage of frozen foods. Stephens Associates Consulting Engineers (SA) provided geotechnical design and consultation for this large specialty structure constructed under a Design-Build Contract. SA planned and coordinated exploration program, and used data gathered in the exploration program to evaluate foundation support for new facilities. The evaluation was concerned with the silty, frost-susceptible native and reused (fill) subgrade soils beneath the structure, potentially subject to long-term subfreezing temperatures. Also of concern is the loading dock area, which will be subject to traffic loads from large trucks.
New Water Pumping and Treatment Facility, Connecticut Water Company, Enfield Connecticut
Status: Design completed 2001
Connecticut Water Company is considering constructing a new water supply using a groundwater pumping and treatment facility. The new facility will include a two-story pumping and treatment building and two 84-foot-diameter, 500,000 gallon storage tanks (Clearwells). Construction costs are estimated to be about $1M. Stephens Associates Consulting Engineers (SA) was retained by the prime engineering consultant to provide geotechnical design for the new facilities. SA’s investigation revealed the presence of soft clays beneath the Clearwells, and designed a load-compensated (“floated”) foundation system to reduce differential settlement while saving substantial construction costs over a deep foundation alternative.
Steel-frame Residence with 20-Foot High Basement Retaining Wall, Methuen, Massachusetts
Status: Construction completed 2001
The residence is a new 4-story steel and wood-frame structure on the north bank of the Merrimac River. The two lower stories are below grade on the up-hill side. The owner retained Stephens Associates Consulting Engineers (SA) to evaluate construction impacts on an old sewer, and to provide structural and geotechnical design for the new structure. A review of the site conditions and project objectives resulted in an integrated approach to geotechnical and structural engineering. Design required a 20-foot high retaining wall with a garage to be located within the structure on the third floor. To reduce footing size and wall thickness, SA’s design used architectural features and novel geotechnology to stabilize the wall and support the garage. The design incorporated exterior concrete driveway retaining walls to anchor the 20-foot high basement wall, and backfill with tire shreds to reduce earth pressures. Interior and exterior basement walls were incorporated to buttress the 20-foot high wall. SA designed steel beams and columns to support the garage floor slab. SA’s overall design approach made possible a project that would otherwise not have been constructed or required much higher construction costs. The Town of Methuen mandated that the Owner retain SA to verify the construction as designed.
Watertown Arts Center, Charles River Square, Watertown, Massachusetts
Status: Design completed 2001
The Town of Watertown is constructing a new Arts Center, including offices, a theater and classrooms in an existing warehouse at the Watertown Arsenal. Construction costs are estimated to be about $4.5M. Stephens Associates Consulting Engineers (SA) was retained by the Architect to provide geotechnical design for the new facilities, to estimate groundwater mounding beneath the proposed soil absorption system (leach field), and to provide consultation and site observation during geotechnical construction.
New Clubhouse and Golf Cart Storage Buildings, Brookmeadow Country Club, Canton, Massachusetts
Status: Construction completed 2001
The Brookmeadow Country Club is modernizing facilities, including demolition of existing structures and construction of a new, two-story Clubhouse and Golf Cart Storage Building. Construction costs are estimated to be about $3M. Stephens Associates Consulting Engineers (SA) was retained by the Architect to provide geotechnical design for the new facilities, to estimate groundwater mounding beneath the proposed soil absorption system (leach field), and to provide consultation and site observation during geotechnical construction.
Additions to Trinity Episcopal Church, Topsfield, Massachusetts
Status: Construction completed 2001
Trinity Episcopal Church in Topsfield, Massachusetts is modernizing and enlarging its facilities. Construction will include new two-story offices, classrooms and amenities. Construction costs are estimated to be about $1M. Stephens Associates Consulting Engineers (SA) was retained by the Architect to provide geotechnical design for the new facilities.
