The American Society of Civil Engineers (ASCE) San Francisco Section honored Simpson Gumpertz & Heger (SGH) with its Outstanding Construction Project of 2017 award for the Shell Martinez Refinery Marine Terminal loading platform seismic mitigation project. As part of this effort, SGH developed an innovative system of fiber-reinforced plastic (FRP) wrap to existing piles, combined with external seismic dolphins to restrain lateral movements of two 450-ft long wharf structures, to prevent overstress of the existing plumb pile system that holds up the platforms. The design concept allowed Shell to continue operating during construction while minimizing environmental impacts on the surrounding sensitive marshlands.
The seismic assessment of the original wharves indicated that the existing 1960s-era prestressed concrete piles and batter piles were inadequate to resist the larger seismic displacement demands associated with new seismic performance standards. The existing piles were insufficiently detailed and vulnerable to damage as well as loss of function if lateral deflections of the wharf deck were too large.
An SGH team that included staff members Bill Bruin, Julie Galbraith, Justin Reynolds, Brian Phan, and Sam Cortes used displacement-based design techniques with nonlinear pushover analyses to demonstrate that the performance of the retrofitted wharves satisfied the requirements of California’s State Lands Commission. Professor Rakesh Goel of California Polytechnic State University, San Luis Obispo, performed an independent peer review of the analysis and design.