某水电站地应力场数值模拟与工程区稳定性分析

Modeling of in-situ stress field in a hydropower station and stability analysis of its project region

根据黄河上游某水电站地下厂房区工程地质勘探资料和原地应力测量资料,用Marc Mentat软件建立了有限元计算模型。利用应力回归分析方法模拟该地区地应力场:首先确定自重和构造应力因素为待回归因素,然后采用回归法原理计算待回归因素的系数,从而模拟出工程区地应力场。对比实测值和模拟值,表明两者在数值和方位上差距均不大。厂房区附近最大主应力值为8MPa左右,最大水平应力近东西向。重力作用对该区地应力的影响要大于构造应力的作用。反演获得的规律与预先推测的结果基本一致。反演结果表明该水电站地下厂房的稳定性较好。

According to the data from engineering geological exploration and in-situ stress measurement of a hydropower station at the upper Yellow River,we establish a finite element model using Marc Mentat software.With stress regression analysis method,we model the stress field in the study region： Firstly,we confirm self-gravity and tectonic stress as the undetermined regression parameters;then regress the correlated coefficients according to regression theory;finally calculate the stress field of project region.Comparing in-situ measurement data and the calculated results,we find out that there are little difference between them both in magnitude and orientation.The maximum principle stresses near powerhouse are about 8MPa.The orientation of maximum horizontal stress approaches E-W.The effect of self-gravity on the stress field is more than that of tectonic stress in the region.The features displayed in our inversion results are broadly in line with our expectation.The inversion results show that the stability of powerhouse is great.