Project Detail

West Wall Santee Basin Bulkhead Repair


Scope of Work

The West Wall Santee Basin Bulkhead Repair Project included the complete rehabilitation of a 410 linear feet bulkhead. The existing bulkhead was built shortly after World War II and became structurally deficient over time, which allowed sediment to pass into the basin, creating multiple sinkholes along the bulkhead. Due to the complexity of the project, as well as the design-build delivery method, Cianbro had a close working relationship with both the prime contractor and designer which led to a project completed on schedule and under budget.

Project Details

  • Demolished and disposed 350 linear feet of existing concrete bulkhead cap and backfilled with compacted GAB for paving and striping
  • Installed 350 linear feet of new sheet pile wall to -49.0 elevation, which was built outboard of the existing wall
  • Installed a new Double C-10 water system with two-inch tie backs
  • Placed tremie concrete between new and existing sheet walls and placed 145 cubic yards of concrete cap
  • Placed 125 cubic yards of underwater concrete wall to reinforce the bulkhead at Pier 225, which remained in use during construction
  • Pier 225 required approximately 400 cubic yards of underwater excavation and backfill utilizing a mix of aggregate & flowable fill

Lean, Innovative, and Unique Project Solutions

The project utilized the Dawson Capping Formwork System to form the bulkhead cap. Per the specifications, the bulkhead was constructed with the soffit elevation below the waterline, which led to the utilization of divers. The Dawson System is a modular form system which was easier to install underwater rather then using traditional overhang brackets.