Photo Credit: Alex Mead
Featured in this photograph is a worker placing tiebacks for an auger cast retaining wall system. Such retaining wall systems are designed to resist all the lateral loads imposed by the sides of an excavation. To place tiebacks the worker first drills into the earth behind the wall using the machine shown, and secures cables with grout in the hole. After the grout has cured and the cables are secure they are pulled tight using jacks and fastened to the wall to hold it in place. Excavation then continues deeper until the next layer of tiebacks is needed. The process is then repeated until the desired depth of the excavation is reached.