Saiful Bouquet was retained in 2002 to seismically retrofit the 537-bed Main Hospital Building at the Martin Luther King, Jr. / Drew Medical Center, the largest of the six medical centers operated by the County of Los Angeles. The Main Hospital building, which is a six-story non-ductile concrete structure designed in 1968, comprises of three separate buildings separated by seismic joints. The buildings have non-ductile concrete shear walls as the seismic bracing system and drilled piles as foundation system. The hospital did not comply with OSHPD’s SB 1953 SPC-2 (life safety) criteria and thus needed to be seismically retrofitted by 2008 or removed from acute care services.
A prior study by another structural firm proposed a seismic retrofit scheme which was very expensive, highly intrusive and required extensive move management. Saiful Bouquet developed an alternate seismic retrofit solution that was not only much less expensive, it was also primarily an exterior solution that could mostly be implemented from the outside and thus was much less intrusive and cut down the move management by more than 80%. This was huge as the county needed to keep as much of the hospital open and functioning through the entire construction process.
Saiful Bouquet utilized advanced state-of-the-art non-linear seismic analysis combined with the latest thinking in soil-structure interaction to develop the structural retrofit scheme. This included explicitly incorporating soil-structure interaction effects to predict displacement demands on the piles and keeping them within acceptable limits. The results allowed for a significant reduction in the extent of foundation retrofit work. The state-of-the-art nonlinear analysis of the non-ductile concrete building and explicit consideration of the soil-structure interaction effects required an intensive effort by the structural engineers which included elaborate technical discussion with OSHPD and getting their buy in. Although such analysis was very trying, the reduction in construction and move-management and the fact that 95% of the hospital could remain operational during construction made the engineering effort extremely worthwhile. Saiful Bouquet obtained OSHPD approval for the SB 1953 SPC-2 retrofit of the project. However, the project was put on hold after the permit was obtained and the county decided to use a different building on the campus for acute care beds (which Saiful Bouquet served as the structural engineer as well).
