抽水蓄能电站大型地下厂房区初始应力场反演

Inversion of Initial Stress Field in Large Underground Plant Area of Pumped Storage Power Station

地应力场特征及分布规律对地下厂房围岩稳定及工程设计具有重要影响。根据某抽水蓄能电站地下厂房地表深钻孔及工程地质条件,建立三维数值分析模型,通过多元线性回归分析,实现了初始地应力场的反演重构。研究表明,深孔实测最大水平主应力为6.7~17.6 MPa;反演模型的量值大小和方向与实测值吻合较好,地下厂房区水平应力为主导,最大水平主应力为16.2~17.4 MPa,应力水平属于中应力水平;厂房区域应力场最大主应力方位角主厂房轴线夹角小于30°,对于厂房围岩稳定有利。应力分布及方位角符合设计要求。研究成果可为类似工程提供参考。

The characteristics and distribution of in-situ stress field have an important influence on the stability and engineering design of the surrounding rock of underground power house.According to the deep surface drilling hole and engineering geological conditions of the underground power house of a pumped storage power station,a three-dimensional numerical analysis model was established,and the inversion reconstruction of the initial in-situ stress field was realized through multiple linear regression analysis.The results show that the maximum horizontal principal stress measured in deep holes is 6.7-17.6 MPa.The magnitude and direction of the inversion model are in good agreement with the measured value,and the horizontal stress in the underground workshop area is dominant,and the maximum horizontal principal stress is 16.2-17.4 MPa.The maximum principal stress azimuth of the stress field in the plant area is less than 30°,and the stress distribution and azimuth angle meet the design requirements.The research results provide a reference for similar large-scale underground projects.