Seismic Resilience Design for a Concrete Box Reservoir

The proposed 110-million-gallon reinforced concrete Headworks Reservoir structures are planned by the Los Angeles Department of Water and Power (LADWP) to be part of the water supply system of the City of Los Angeles, and resilience of the water supply system is crucial for continued water supply in the event of a disaster, such as an earthquake. The seismic resilience of the reservoir structure is a function of the cracking and associated leakage that would be expected due to static loading and during the design level earthquake. Evaluation of the seismic deformation of the structure was accomplished utilizing a soil-structure interaction (SSI) model to evaluate performance of the reservoir structure in an earthquake, after the initial design based on standard code-based design procedures. SSI was used to provide information on the structural behavior of the reservoir, and to understand relative movement of inlet and outlet pipelines. In addition, a leak detection system was incorporated into the design. PROJECT DESCRIPTION AND GEOLOGY The proposed Silver Lake Complex Replacement Project consists of the Headworks Reservoir Complex (East and West Reservoirs), a Hydropower Plant to be constructed on approximately 12 acres within the Headworks Spreading Grounds, and a series of new water conveyance pipelines to and around the existing Silver Lake Reservoir (not at the location of the proposed reservoir site). The current proposed location of the reservoir complex including major project components planned are