1976年唐山地震地下工程震害的分布规律
DISTRIBUTION OF UNDERGROUND SEISMIC INTENSITY IN THE EPICENTRAL AREA OF THE 1976 TANGSHAN EARTHQUAKE
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摘要: 本文通过对1976年唐山7.8级地震地下工程内部宏观现象的调查分析, 指出高烈度区地下工程震害是随深度增加而呈指数曲线迅速衰减的, 约到500米深处呈一常数.极震区地下平面烈度, 受发震构造控制, 向两侧衰减迅速, 超过同位置地面烈度的衰减速度.Abstract: Based on results of underground observations (in coal mines) in the epicentral area of the 1976 Tangshan Earthquake magnitude 7.8, it can be seen that beneath zones of higher seismic intensity of the area destructions attenuate rapidly with depths exponetially, becoming nearly constant at about 500 m below the surface. The distribution of seismic intensity in the horizental plane underground is controlled by the earthquake generating faults. Seismic intensity attenuates much more rapidly on both sides of a fault than on the surface vertically above.