唐山地震引起北京地区烈度异常区的原因分析

唐山地震导致北京地区出现烈度异常区的主要地质因素是砂土液化、断层和潜山。砂土液化分布于地势低洼、新近沉积的饱和砂层地区,并位于地下水埋藏浅和迳流滞缓地区。断层控制异常区呈带状分布。潜山的影响主要在于其形态引起的地震动“放大”作用。几次地震对某些地区的影响,常重复出现烈度异常,反映在该地区具有长期起作用的地质因素

ON DISTRIBUTION OF INTENSITY ANOMALIES IN THE BEIJING REGION CAUSED BY THE TANGSHAN EARTHQUAKE

This paper deals with the geological factors affecting the distribution of seismic intensity in the Beijing region during the Tangshan earthquake. It is suggested that the geological factors leading to the intensity anomalies in the Beijing region include mainly liquefaction of sandy soil, faults and buried hills. As the liquefaction of saturated sandy soil caused by the earthquake is related with the permeability of groundwater, earthquakes tend to build up easily the pressure in the region wit