摘要
本文提出在研究地震烈度衰减规律时应考虑区域地形地貌背景的观点。文中首先以海城地震为例,利用该地震的等震线和区域地形地貌资料阐述了山区烈度衰减快而平原烈度衰减慢的观点。然后,对华北地区近代历史地震等震线资料进行平原和山区类型划分,并用各条等震线的等效半径分别按地形地貌类型作统计分析,给出了平原和山区的烈度衰减规律。统计结果进一步证实了上述规律性。例如,对于华北地区的破坏性地震(震级为6、7、8),当地震烈度衰减一度时,平原和山区的相应震中距增加的距离之比平均约为3/2。本文提供的初步研究结果表明,考虑地形地貌对地震烈度衰减规律的影响是一个值得注意的问题,进一步研究这一问题对工程场地的地震危险性估计有一定的实际意义。
Importance of regional background of topography and geomorphy is stressed for studying attenuation of the Seismic intensity. This viewpoint is first illustrated by that the attenuation in the mountainous area is faster than that in the plain area in terms of data from the Haicheng earthquake, 1975. The historical isoseismals in the northern China are then classified into two types according to the fact that the isoseismal belongs to the plain or the mountainous area in the region. The average attenuation laws are finally obtained by regressive analyses in terms of data of equivalent epicentral distances for each type of isoseismals in that region. The statistical results further prove the above viewpoint, and the ratio of epicentral distance increments in the plain and in the mountainous area in northern China is about 3/2, on average, as the Seismic intensity decreases one degree.
出处
《地震工程与工程振动》
CSCD
北大核心
1990年第1期35-40,共6页
Earthquake Engineering and Engineering Dynamics
基金
地震科学联合基金
