裂隙岩体的变形模量及强度特性是工程界关注的焦点,其关键是岩体变形模量及强度的尺寸效应和表征单元尺寸(REV)。根据锦屏二级水电站大理岩裂隙统计分布规律及岩块和结构面力学特性试验成果,确定岩块和结构面的本构模型,建立考虑无厚度裂隙面力学响应的分析模型。研究不同尺寸、不同统计窗裂隙岩体的力学响应特征,并重点研究裂隙岩体变形模量和单轴抗压强度的尺寸效应、REV特征以及各向异性特征。该研究方法为裂隙岩体的宏观力学参数取值提供参考,研究成果也为锦屏二级水电站工程岩体参数取值提供了依据。
Deformation and strength characteristics of fractured rock masses are always the focus in geotechnical engineering. The key for determining deformation modulus and strength parameters is to study representative elementary volume(REV) and scale effects of fractured rock mass. Based on field investigations of fracture distribution in rock mass of Jinping Ⅱ Hydropower Station, fracture network and meshes considering zerothickness fractures for numerical simulation are generated. Mechanical models of rock and fractures are established separately based on laboratory triaxial and shear test results. Scale effects, REV and anisotropic properties of rock mass are studied by FEM considering different scales and orientations in site. The achievements will benefit parameter determination in Jinping Ⅱ Hydropower Station; and the method can offer important reference for other practical engineering.