1976年唐山地震地表断裂反映的力学信息

Mechanical Information Reflected from the Surface Ruptures Produced during the 1976 Tangshan Earthquake

一、序言地震时发生的地表断裂,是震区应力场及其随地震而发生的动态变化所造成的地表宏观现象,对研究震时震区受力方式、地震发生机制和震区断层活动状况,都是很有价值的宏观记录。 1976年唐山地震,在东起渤海边西至通县,南起天津北至迁安的范围内,产生了大量地表断裂。这些地表断裂有的在土层中,有的在基岩内,有的在公路和机场跑道上。

Tremendous surface ruptures were produced during the 1976 Tangshan earthquake,most of which resulted from the sudden variation of the focal stress field.Therefore,they may provide useful mechanical information for a further study of the great event.In this paper we re—analyze previously investigated surface rupture data to study the stress pattern and relevant fault activity in bedrocks.