原地应力对钻孔应变耦合系数的影响分析

Impact Analysis of Situ Stress on Borehole Strain Coupling Coefficients

利用4层介质耦合钻孔模型,研究该模型中耦合介质弹性参数变化对钻孔应变耦合系数的影响。计算结果表明:在钻孔耦合介质中,弹性层等效弹性模量变化对面应变耦合系数的影响大于对差应变的影响,与观测结果对比,分析发现面应变耦合系数观测值存在明显非均匀性,而且其大小与台站的背景应力场存在对应关系。

Using the established four layer medium coupled drilling model,we calculated the effect of elastic parameters variation of borehole coupling medium on coupling coefficients of borehole strain by stress function method.The calculation results show that the effect of equivalent elastic modulus change on the coupling coefficients of the plane strain is larger than that of the shear strain in the borehole coupling medium.Comparing with the observed data,the observation value of the coupling coefficients of the plane strain exhibits a significant heterogeneity,as well as its value may relate to the background stress field of the station.