断层带岩体变形模量对坝基稳定性影响

Influence of Deformation Modulus of Fault Rock Masses on Dam Foundation Stability

变形模量是表征断层带岩体力学性能的一个重要参数，而断层带岩体变形模量与其所处的环境有密切关系。以理论分析和现场试验为基础，以三维数值分析技术为主要研究手段，结合大型水电工程实例，对断层带岩体变形模量对坝基整体稳定性影响进行了分析研究。研究结果表明：大坝建成水库蓄水以后，在未受到库水渗透影响的前提条件下，位于坝基部位的断层带岩体变形模量会有一定程度的增大。断层带变形模量从0．6 GPa 一直增加到4．0 GPa，使得断层带岩体所在坝段关键点水平位移降低0．544～0．846 mm、垂直位移降低1．190～2．232 mm、最大拉应力降低0．06 MPa，有利于提高大坝的整体稳定性。

The deformation modulus of fault rock mass is an important parameter to denote its mechanical characteristic,and it is obviously related to the environment.A large scale hydropower project was taken as an example to analyze the influence of deformation modulus of fault rock masses on dam base stability based on site test and theory and 3D-numerical analysis.Result indicates that if the deformation modulus of fault rock mass increases from 0.6 Gpa to 4.0 GPa,the horizontal displacement at key point in the dam will decrease 0.544 0.846 mm,the vertical displacement at key point in the dam will decrease 1.190 2.232 mm and the maximal tensile stress at key point in the dam will decrease 0.06 MPa because of the increase in the deformation modulus of fault rock mass after impoundment of hydropower station and without influence of water infiltration,which is advantageous to stability of dam base.