The October 3, 1974, earthquake caused severe damage to buildings of adobe and quincha construction, and also to masonry, reinforced masonry, and reinforced-concrete structures in Lima and vicinity. Most of the damage to well-built structures was due, in part, to the lack of lateral resistance in the original design and to the fact that this earthquake had more energy around 0.4 seconds period than prior destructive earthquakes. Water tanks on the roofs of structures with four or five stories were damaged. Well-engineered single-story buildings were less affected than taller structures.
Considerable structural damage to reinforced-concrete structures occurred in the districts of Barranco, La Campiña Molina, and Callao. In La Campiña three-story building partly collapsed and other buildings sustained considerable damage. In La Molina, the buildings of the Agrarian University sustained severe damage, and some collapsed. In Surco, the district adjacent to La Molina, there was no appreciable damage. In Callao, a four-story building collapsed, and the upper half of a concrete silo collapsed. In reinforced-concrete structures, column ties were frequently small in diameter, widely spaced, and not well connected. Usually, the reinforcement of resisting elements had no relation to their stiffnesses. Front columns in school buildings were restrained by high brick walls and had rather short effective lengths to allow building displacement in that direction. The windows in the rear walls gave the rear columns a much greater effective length. Therefore, a longitudinal displacement induces large shear forces in the front columns where most of the severe damage occurred. This problem was not considered in the design of these structures.