The Virginia Department of Transportation (VDOT) has achieved a major milestone on the Woodrow Wilson Bridge Project with the completion of its first major landside contract. Strengthening the ground between Telegraph Road and U.S. Rte. 1, essential to supporting the wider future Capital Beltway, was completed in late April--on schedule and under budget. The $35 million Ground Improvement Contract, completed by Shirley Contracting Corp., was a necessary part of Virginia's $1 billion portion of the Wilson Bridge Project due to weak soil that exists where Virginia's new Capital Beltway, ramps and bridges will be built. Completion of this time-sensitive work is critical to the schedule and success of the overall project, as it ensures the soil's readiness for new construction by literally laying the groundwork for multiple construction activities in Virginia to occur.
"The Ground Improvement Contract was a necessary first step on the Woodrow Wilson Bridge Project, as soil that would support the future Beltway was too weak and unstable," said Ronaldo "Nick" Nicholson, P.E., Woodrow Wilson Bridge Project Manager for VDOT. "By strengthening the soil through the use of a variety of innovative geotechnical engineering techniques, we are able to ensure the future roadway will have the necessary foundations in place. The completion of this effort exemplifies VDOT's commitment to the on-time delivery of this important transportation facility."
Virginia's ground improvement work started in late 2001 and showed steady progress each week. To ensure the contract's success, two separate engineering techniques were used, with the primary goal of strengthening the underlying weak soil by accelerating settlements of existing soil, rather than removing and replacing soil. One technique used involved inserting "PV or Wick Drains" up to 40 ft deep into the ground. The other method, called "Deep Soil Mixing" involved strengthening soil by mixing cement with existing soil.
