Microtunneling, Open Shield Pipe Jacking, Hand Mining
As a subconsultant to Kimley-Horn, Bennett Trenchless Engineers provided trenchless design services for over 11,000 feet of trenchless casing installations for the San Antonio Water System through the San Antonio Military Medical Center base. Microtunneling was specified for much of the trenchless installation due to gravelly conditions below the water table that can be prone to flowing behavior. A significant challenge was working within the existing narrow right-of-way which was constrained by parallel overhead utility lines which complicated use of large equipment to excavate the launch and reception shafts. Unstable soil conditions also posed a significant challenge and required the use of microtunneling to stabilize the face and control groundwater inflows into the large diameter tunnels.