NEHRP Clearinghouse

Investigation of Reinforced Brick Masonry Buildings Undamaged by the San Fernando Earthquake.
Adham, S. A.
National Science Foundation, Washington, DC. Office of Planning and Resources Management., May 1981, 188 p.
Behavior of the buildings of the Sepulveda Veterans Administration Hospital during the 1971 San Fernando earthquake was examined. The study explored why these buildings sustained minimal structural damage while other buildings in close proximity sustained major damage. A literature review was conducted and seismic input motions at the site during the earthquake were estimated. Verifications of seismic analysis techniques, using a two-dimensional finite element model, were determined through studies of observed earthquake damage to a six-story building. Relative displacements were calculated at the expansion joints and compared to damage of the flexible joints. Also verified were seismic analysis techniques through a study of observed earthquake damage to the boiler house building. A two-dimensional finite element analysis was conducted, followed by simple hand calculations. Results of both analyses were compared to observed cracks from overstress conditions. The calibrated motions were used as input to a three-dimensional model of a reinforced brick masonry building. The building's behavior and the effects of expansion joints on its performance were evaluated. Performance criteria were developed for assessing the response of masonry buildings during the earthquake and evaluating the effect of expansion joints on relieving internal stresses. Conclusions and recommendations are provided.
San Fernando Earthquake (1971); Damage assessment; Earthquake resistant structures; Dynamic response; Buildings; Ground motion; Finite element analysis; Brick construction; Earthquakes