Publication Abstract

Proceedings of the Deep Mixing 2015 Conference, (DFI)

Cement Deep Soil Mixed Walls/Grout Plug for Groundwater Cut off and Excavation Support at the Bart Warm Springs Extension
Douglas R. Jenevein, Schnabel Foundation Company, United States; Mitchell L. Fong, Parsons Brinckerhoff, United States; Thomas S. Lee, Parsons Brinckerhoff, United States; Harry Schnabel, Schnabel Foundation Company, United States

The Warm Springs Extension (WSX) is one of a series of projects that will eventually extend the Bay Area Rapid Transit System (BART) from Fremont to San Jose, California. A cut and cover tunnel was used for a portion of the extension that runs through Fremont Central Park to minimize the impacts that an at-grade railway would have on the Park. A cement deep soil mix (CDSM) wall was selected by the engineer as the preferred method of providing structural support and groundwater cut-off for a portion of the tunnel where it passes through an important aquifer and near Lake Elizabeth. In addition to the CDSM wall, a jet grout plug was constructed at the base of the tunnel to provide a complete groundwater cut-off. This paper will discuss the unique quality assurance and quality control measures taken for the soil mix wall and jet grout plug as well as the methods used to repair leaks and mitigate water seepage through the exposed wall and grout plug.

 article #2070; publication #1013 (DM-2015)