Serving as the geotechnical consultant, we developed the subsurface exploration program for the project, which included over 180 borings that explored to 200 feet deep. Geotechnical analyses included seismic evaluations, soil liquefaction, development and evaluation of design phase pile load test program, and comprehensive soil/structure modeling of rock-socketed drilled shaft foundations. Challenges included soft soil conditions, environmental concerns and a tight schedule.
The Solutions Unearthed
- We provided preliminary and final geotechnical reports including recommendations for foundation design, construction, and minimization of excavation for the foundations to avoid environmental contingencies. In addition to the main span, the project included roadways, retaining walls, temporary and permanent embankments, and temporary bridges.
- Eight-foot shaft diameter steel cased shafts to rock with rock sockets were drilled to depths over 200 feet. The Western Approach Viaduct is the first in Connecticut to use 20-inch square precast concrete friction piles.
- Consulting services during construction included review of submittals for cofferdams, temporary work trestles, piles and drilled shaft analysis of testing results and implementation of design changes.
- Work also included the geotechnical aspects for design and installation for the relocation of twin 48″ OD HDPE pipes. The pipes spanned 1,800 feet across the New Haven Harbor.