KCI provided value engineering and bridge design services to Lane Construction to replace the U.S. 176 bridge over the Broad River. The 89-foot-wide, 1,126-foot-long, 10-span superstructure consists of a cast-in-place deck on AASHTO 72-inch Modified Bulb-T Beams. The substructure consists of drilled shaft and rock socket deep foundations. KCI coordinated the efforts of the value engineering team to provide revisions to the stage two substructure design. The re-design of the substructure was proposed to provide reduced drilled shaft sizes and lengths from what was constructed in stage one of the project. Our teams design efforts led to a decrease in the foundation elements size for bents two through 10. The end result was a reduction in the amount of drilling, rock excavation, and in material quantities for concrete, reinforcing, and construction casing. These reductions were provided while still allowing similar stiffness of the substructure elements between stages one and two.
The re-design effort focused on making the bridge more constructible, while reducing overall material cost and increasing the speed of the construction process.
R. Eric Burgess, PEPractice Leader
The reinforcing cages were also modified to eliminate telescopic rebar at seven of the bents. In addition to the substructure re-design, engineers also revised the geometric design of the proposed pedestrian pathway traveling below the bridge, to ensure that maintenance vehicles would have the proper clearance.
The value engineering allowed the contractor to complete the construction of the substructure in a reduced amount of time and below their original budget. KCI’s innovative value engineering study and design saved the client and SCDOT more than $2 million.