论文部分内容阅读
一、前言最近十几年的地震观测资料表明,豫北及邻区的地震主要集中发生在某些特殊的构造部位,如:林县震区,磁县震区、菏泽震区等。这些地震集中区不仅有大量微小震发生,而且还发生了几次中强地震。如1980年8月2日林县Ms4.6级地震,1983年11月7日荷泽Ms5.9级地震等。这些地震活动,引起了有关人员的注意。不少同志就该区的地震活动背景和活动特征等问题进行了多方面探讨。本文采用有限元数值模拟的方法,即根据不同介质的物理参数和边界的作用方式模拟本区构造应力场模型;并根据最大剪应力破裂准则,将这些模型与本区近十四年来M≥3级的地震分布情况进行比较,选择计算模型中与实际地震分布情况吻合较好的物理条件和力学条件,以探求本区可能存在的相对高剪应力区,并模拟出本区介质的物理特征以及所受应力的状态。
I. Foreword Seismic observation data of the past ten years show that the earthquakes in the north of Henan and its neighboring areas mainly occur in some special tectonic positions, such as the Linxian earthquake zone, the Cxian earthquake zone and the Heze earthquake zone. These earthquake-concentrated areas not only have a large number of minor earthquakes, but also occurred several moderate earthquakes. Such as the Linxian Ms4.6 earthquake on August 2, 1980, the Ms5.9 Heze Ms5.9 earthquake on November 7, These earthquake activities have aroused the attention of relevant personnel. Many comrades conducted many discussions on such issues as the seismic activity background and activities in the area. In this paper, finite element method is used to simulate the tectonic stress field in this area according to the physical parameters of different media and the mode of boundary effect. Based on the maximum shear stress rupture criterion, these models are compared with the M≥3 The comparison of the distributions of earthquakes in this area and the selection of the physical and mechanical conditions which are in good agreement with the actual earthquakes in the calculation model can explore the possible high shear stress areas in this area and simulate the physical characteristics of the medium in this area and The state of stress.