摘要
本文主要目的在于研究唐山地震中期前兆的形成机制。采用二维非线性有限元模型,对穿过唐山的剖面结构进行模拟计算,研究剖面结构的不均匀性与震源区内应力集中的关系,岩石膨胀与地面隆起,以及其他震前异常的关系。研究结果表明,在震源体内存在坚固体的条件下,在地下几公里至十几公里处发生岩石膨胀是可能的,由此在地面造成隆起,并为地震活动异常,波速异常,深部物质上涌提供条件,故岩石膨胀可能是唐山地震中期前兆的基本机制。
The main purpose of this paper is to study the mediumterm precursory mechanism of the 1976 Tangshan earthquake. We use 2-D nonlinear finite element model, to simulate the structure of the profile across Tangshan region, to analyse the relationship between the nonhomogeneousity of profile structure and the stress concentration in the source region, between the rock dilatation and the ground -uplifting, and other anomalies before the event. It is shown that if there is a solid body under the ground surface for a few or more than 10km in the source region, the rock-dilating is possible. It makes the ground upheaval, and causes seismicity and wave velocity anomaly, deep material up-welling. So the rock-dilatation may be the basic medium-term precursory mechanism of the 1976 Tangshan earthquake.
出处
《中国地震》
CSCD
北大核心
1989年第2期27-34,共8页
Earthquake Research in China
基金
地震科学基金资助的项目
