水电站大型调压井区初始地应力场反演分析

Regression Analysis of Initial Stress Field of Large Surge Tank Area for Hydropower Station

利用离散的有限个测点实测资料建立较为可靠的围岩初始应力场。结合丹巴水电站调压井区域的地质条件,基于地应力实测资料,引入灰色控制系统理论,在此基础上采用三维有限元法和静态的三因素灰色计算模型GM(0,3)对岩体初始应力场进行回归反演分析。计算结果表明:长廊式调压井区存在较大的水平向地质构造作用,岩体的地应力由自重和构造应力叠加而成。推荐方案三回归效果良好,测点的回归值与实测值无论在量值还是方向上都较为接近,从而获得了较为合理的初始应力场分布,为调压井的开挖模拟及稳定性分析提供了依据。

A relatively reliable surrounding rock initial stress field is established based on the observed data of finite discrete points. Combining with the geological conditions of surge tank area of Danba hydropower station,a regression analysis is made on the stress field through 3-D finite element method and the static three factors grey model GM（0, 3）based on in-situ measured data and the gray control system theory. The results show that the loggia surge tank area has great horizontal geological structure, whose rock body has a ground stress superposition by the gravity and tectonic stress. The third recommended scheme has good regression effect,whose regression value is more close to the mea-sured value in both the magnitude and direction. A reasonable distribution of initial stress field is obtained thereof, which provides a reference for excavation simulation and stability analysis of surge tank.