基于现场试验的岩体变形模量尺寸效应研究

岩体力学参数具有随机性和不确定性，合理确定岩体力学参数是岩土工程稳定性分析的基础和关键。以某水电站前期研究的110个钻孔弹模测试数据为研究样本，对其进行了统计特征分析，确定变形模量的概率分布特征更符合Weibull分布。以钻孔弹模仪承压板尺寸为岩体变形模量研究的样本尺度，岩体由该尺度的岩样叠加而成，建立了不同尺寸的立方体岩体数值分析模型，按照Weibull分布随机给出各岩样的变形模量，在此基础上对不同尺寸的岩体分别进行5 000次单轴压缩试验的数值模拟，得到了不同尺度岩体等效变形模量的变化特征，确定了岩体等效变形模量的REV。基于现场实测岩体变形模量与概率统计理论相结合研究岩体变形模量是一个新的尝试，可为该水电站工程岩体力学参数的合理取值提供依据。

Study of size effect of rock mass deformation modulus based on in-situ test

It is the key step for geotechnical engineering stability evaluation to determine suitable mechanical parameters of rock mass due to random distribution of its parameters. The statistical analysis of 110 data from borehole jack tests conducted from earlier research of a hydropower station shows that the deformation modulus more closely matches the Weibull distribution. Then the cube rock masses of various sizes, each of which comprises a number of cube elements, are simulated numerically. The size of each element is identical with that of bearing plate of borehole jack test instrument; and the deformation modulus of each cube element is given randomly by Weibull distribution. Each of rock masses is simulated by 5000 uniaxial compression tests; and then the change of equivalent deformation modulus with rock mass size is obtained, which determines the REV of equivalent deformation modulus. It is a new attempt to survey the macro parameters of rock mass by combination of in-suit test and probability statistics theory, so as to provide a useful reference for the parameter determination of rock mass in this hydropower station.