City of Atlanta Department of Watershed Management
Cheshire Bridge Rd and Peachtree Creek
About the Project
Stability Engineering provided temporary shoring at the Diversion pump structure and the Jet Mix pump station. Design challenges included tight site clearances, inconsistent bedrock elevations, and difficulty installing wall tiebacks. The walls were tied back using a combination of deadman piles, helical piles, and grouted rock anchors. Due to the inconsistent bedrock depths and deep excavations, most piles did not have any embedment at the toe and relied solely on the tiebacks for stabilization. For this reason, each tieback on the entire project was load tested to ensure the design load was achieved with the proper safety factor. Installation of the tieback piles had to be constantly modified due to site conditions using a variety of installation heights, lengths, and angles. Several rows of helical tiebacks were changed to grouted rock anchors due to bedrock interference.
For a third component of this project, Stability Engineering designed and performed load tests on rock anchors to assist in achieving the desired hold down capacity for a large water storage tank. Over 350 vertical rock anchors were installed into underlying bedrock, and approximately 10% of the rock anchors were load tested per the instructions of the project Engineer of Record.