断裂扰动区隧道初始地应力场数值反演

Numerical reversion of tunnel initial stress field in fault disturbed zone

初始地应力场是隧道及地下工程关注的核心问题之一,特别是在断裂构造区域,地应力分布受到扰动,出现量值与方向的改变。目前初始地应力反演主要基于地应力实测值,但大量的隧道工程缺乏地应力测试数据。针对这一问题,提出了无地应力实测值条件下基于断层产状与断距的初始地应力场反演方法:拓展位移不连续法数值方法,利用断裂构造自身特性,引入断层变形模型,建立断裂构造的位移不连续法数值解法,利用该计算内核实现初始地应力场回归反演。工程案例分析表明,断层断距反演值与实测值基本吻合,地应力反演值与实测值较为接近,断裂构造周边地应力场呈现不均匀特性。

Initial stress field is one of the key problems in tunnel and underground projects,especially in the fault zone.At present,the initial stress inversion is usually based on the measured in-situ stress,but a large number of tunnel projects are lack of measured in-situ stress data. To solve this problem,the initial stress field inversion method based on the attitude of fault and fault throw was proposed,which can be conducted without measured in-situ stress data: the displacement discontinuity method( DDM) is devised for using fault characteristics,the fault deformation model is considered in the new DDM program,and then the DDM computational kernel was used for the initial stress field regression inversion. Case analysis shows that the stress field around the fault is not uniform,the inversion of the fault throw is basically consistent with the measured values,the measured in-situ stress is close to the calculated value.