断裂构造体系的形成和扩展过程的力学分析及应用

本文运用断裂力学的原理和方法,研究了地壳断裂构造体系形成的力学机制和过程。对地球广泛存在的两组X型剪切断裂体系的方向进行了分析计算,认为地球转动和内部热活动是形成X型剪切断裂系的主要原因。X型剪切断裂系形成后由于总体和局部应力场变化,它们中的部分逐步固结闭锁,部分更加活动,从而发生进一步的扩展和相互作用。本文根据单条孤立断裂和断裂系扩展过程的分析计算,对剪-张型和剪-压型锯齿状断裂的形成过程进行了研究。最后还举例讨论了断裂体系及其扩展在地震预报方面的应用。     

横向非均匀性对地壳应力场的影响

本文将地壳模拟成一个受地幔弹性恢复力作用的薄壳,用有限单元法分析了地壳横向温度及厚度变化引起地壳应力场的变化,并采用薄板模型对应力的特点和数值进行了估计和讨论.在温度和厚度变化的地区会产生较大的附加应力,可达几十巴至百巴.与观测对比,发现这些地区与地壳运动和地震活动区是密切相关的.     

MECHANICAL ANALYSIS OF THE FORMATION AND PROPAGATION PROCESS OF FRACTURE SYSTEMS AND ITS APPLICATION

In this paper, the mechanical mechanism and propagation process of crustal fracture system are studied by using the principle and method of fracture mechanics. The trendings of two pairs of the X-shaped shearing fracture networks existing widely on the crust are calculated and the main causes to form them from the earth's rotation and thermal activity are considered. After the formation of X-shaped shearing fracture system, parts of them became a closed one but parts of them became more active and propagated further or interacted on each other since the stress field changed in the whole or regionally. Based on the propagating processes of single fracture and fracture systems, the formation process of the zigzag fractures of shear-tension and shear-compression are studied. Some examples showing that the propagating processes of fracture system can be applied to the research of earthquake prediction, are also indicated in this paper.