Located on the banks of the Ohio River, the Water’s Edge Sewer Separation Project directed by SD1 called for 1,200 feet of 42” diameter sewer pipe to be installed along with a headwall and several manhole structures. Portions of the project required installation of these items, to depths of 17’, parallel to the toe of an existing 15-foot-tall MSE retaining wall. This MSE retaining wall had already experienced one failure. Thus protecting this wall, with driveway and condo units above, was essential. Civil Solutions Associates (CSA) was contracted by ConnHurst Construction to design the temporary shoring system and backfill procedure for this portion of the project.

CSA devised a system, utilizing the coordination of trench boxes during excavation and backfill. This allowed for the sewer and manholes to be installed without compromising the integrity of the existing MSE wall. During implementation, CSA surveyed and monitored any settlement or deflection in the block retaining wall. Measurements were taken twice daily during work days and upon completion of work. No appreciable settlement or deflection was noted in the retaining wall. With the implementation of this procedure, ConnHurst Construction was able to meet the 15-day construction deadline with a presumed savings.

Due to the previous failures of the MSE wall, prompt remediation was essential. By involving CSA early on in the project, planning and designs were able to be discussed and finalized, within a short time frame, prior to mobilization to the site. The close proximity to the site allowed CSA to provide real time solutions if any issues arose.