Caracas Venezuela Earthquake (1967) Tall Building Damage Review. Optimum Seismic Protection for New Building Construction in Eastern Metropolitan Areas

摘要

Damage from the earthquake was widespread throughout the Valley, but the Los Palos Grandes area was particularly hard hit. Four major buildings collapsed. Total loss of life exceeded 275 people. One major conclusion of studies made by a Presidential commission is that the action of the soil beneath a building heavily influences the amount of damage that a building sustains. The most important single measure of the soil effect is the depth-to-rock distance. The quality of the damage data dictated that the variability of the alluvium could be meanfully considered only by dividing the Caracas Valley into two areas; the Los Palos Grandes district, where the soil is more than 450 feet deep, and the rest of the valley, where tall buildings are constructed over relatively shallow soils. Most of the tall buildings were designed according to the 1955 Venezuela Standard for Building Design of reinforced concrete. Matrices were constructed for buildings in height ranges: five to eight stories; nine to fourteen stories; and fiftenn to nineteen stories. For buildings five to eight stories high, the spectral acceleration appears to have been smaller in the Los Palos Grandes area than the rest of the valley. This may be due to the filtering of higher frequency earthquakes components by the deep Los Palos Grandes soil. While buildings nine to fourteen stories high had similar spectral acceleration values in both areas, the fifteen to nineteen story high buildings in the Los Palos Grandes area had higher spectral acceleration values due to soil amplification.