In the largest Design-Build Project MassDOT has ever awarded, Stone Pillar Engineering Limited reconstructed 4 miles of I-95 and 10 bridges in a joint venture with Walsh. This encompassed two distinct 1400’ Whittier bridges to replace the aging original bridge, all while never limiting traffic to less than 6 lanes during peak hours. During the RFP phase and into the design phase after the award, the Project Team worked to develop a cost and resource-loaded Critical Path Method schedule and a robust NET TCP Quality Control Plan. The design integrated safety, constructability, and cost with the owner’s concerns for maintenance and life cycle, as well as the other stakeholders’ concerns with environmental protection, traffic flow, and the classic appearance of this signature bridge. One element of this project includes reducing the length of the Evans Place Bridge by over 20’ and converting it to a precast next-beam bridge from a steel girder bridge.

Additionally, relocating over 1000 feet of duct bank to the median from the right-hand lane minimizes the impact on the traffic. It creates a cleaner utility corridor with drainage in the median. To solve settlement issues due to unsuitable soil under the roadway, we employed a 40-foot-high Expanded Polystyrene (EPS) block wall under the highway. This required developing a seldom utilized utility corridor carved into the EPS blocks for the drainage system at the road’s edge. The design and reconstruction of 8 miles of stormwater management system entailed over 500 drainage structures up to 8’ in diameter and over 20’ deep, over 50,000’ of drainage piping up to 48” in diameter, over 24,000’ of water quality swale, and 16 infiltration basins. In addition to the reconstruction of the highway, over 2 miles of shared-use paths were built along the highway to carry pedestrians and bicyclists across the river.