南北地震带应力场演变的数值模拟研究

STUDY OF SIMULATION FOR THE EVOLUTION OF STRESS FIELD ON NORTH-SOUTH SEISMIC BELT IN CHINA

摘要:

应用有限元方法,考虑主要地质构造情况,就粘弹介质状态下南北地震带及其相邻区域的应力场时空演变过程进行了数值模拟研究.计算了10万零10年累积载荷作用下模型的应力场演变,发现在周边板块不断推挤作用下,当整个南北带的应力松弛趋于稳定后,带上应力场的总体扰动大小取决于印度-澳大利亚板块、菲律宾板块和太平洋板块的共同作用.南北地震带上呈现出的"地震南北呼应"现象,就是区域应力场达到平衡态后,整个南北带对外载荷(板块边界力)作用的总体反应.

Abstract:

Using finite element method, the time-space evolution of stress field on North-south Seismic Belt and adjacent region is simulated,considering the geological structures and designing the model with viscosity characteristic. Through simulated calculation of evolution of stress field affected by 100, 010 years accumulated loading,it is found that the joint continuous effect from India-Australia plate, Philippine plate and Pacific plate determines the disturbance quantity of the stress state on the belt after the creep deformation has approached steady state. The phenomenon of seismic echo on North -south Seismic Belt is a synthetic reaction to the external loads (plate boundary force) after the regional stress field reaches a equilibrium state.