多孔岩石中应力波传播特性及震源函数

建立了两种着重描述多孔岩石的塑性压缩(孔隙坍塌)机理的弹塑性本构模型,分别为将孔隙压实过程计入P-V关系的变模量理想塑性包络面模型和将孔隙演化行为计入帽盖的双屈服面帽盖模型.在此基础上,对地下球形药包起爆引起的弹塑性波在多孔凝灰岩中的传播过程进行计算,揭示了多孔岩石中应力波传播的一些基本特性.并采用改进的帽盖模型,研究了多孔凝灰岩中地下爆炸震源函数的特性,着重分析了孔隙度对震源函数的稳态值、拐角频率以及过冲特性的影响.

Stress waves and seismic source function in porous rock

Firstly,two elasto-plastic constitutive models were proposed to describe the complex mechanical behavior of porous rock,especially,pore collapse. One is variable modulus Drucker-Prager criterion which considers the effect of pore collapse on mechanical behavior of porous rock,and the other is modified cap model which introduces porosity evolution based on mixture theory and general cap model. Secondly,spherical elasto-plastic wave propagation in porous tuff induced by underground explosion was numerically simulated by FDM,and some basic characteristics of stress waves in porous rock were illuminated. Lastly,based on the numerical calculations on the stress waves in porous tuff,the main characteristics of seismic source function in underground chemical explosion were studied,and the influences of porosity on seismic source function were analyzed.