大理岩岩体力学特性的水压-应力耦合试验研究

为研究裂隙水压力与应力条件对大理岩裂隙岩体力学特性的影响，利用MTS815 Flex Test GT 岩石力学试验系统，采用特殊的试样制备和地质过程模拟方法，制备成与试验机围压系统、渗压系统融为一体的大理岩裂隙岩体试件，并对其进行了不同水压、不同围压下的水压 应力耦合三轴压缩试验。试验结果表明：大理岩岩体强度性能与变形性能均具随水压升高而减小，随围压升高而增大的特征；水压从0到4 MPa的变化过程中，强度参数f 减小了20%左右，内聚力C大幅降低，变形模量E₀及E₅₀分别减小了7.7%和5.9%；围压从5 MPa到30 MPa的变化过程中，f 值略有降低，C值增大了2倍多，变形模量E₀及E₅₀分别增大了58%和50%。这些成果揭示了大理岩裂隙岩体力学特性的裂隙水压效应与围压效应，对实际工程问题的研究具有重要的参考价值。

Water Pressure-Stress Coupling Tests on the Mechanical Properties of Marble Rock

To investigate the effect of fracture water pressure and confining pressure on the mechanical properties of fractured marble rock,we produced marble rock specimens which fit with the confining pressure and osmotic pressure of testing machine system(MTS815 Flex Test GT) via special techniques and geological process simulation.We then carried out water pressure-stress field coupling triaxial tests under different water pressures and different confining pressures.Results showed that the strength and deformation properties of the rock decreased with the increase of water pressure,and increased with the rise of confining pressure.During water pressure changed from 0 to 4 MPa,the strength parameter f decreased by 20%,the cohesion C decreased remarkably,and the deformation modulus E0 and E50 decreased 7.7% and 5.9% respectively.During confining pressure changed from 5MPa to 30MPa,f decreased a little,C increased more than 2 times,E0 and E50 increased 58% and 50% respectively.These conclusions reveal the marble rock’s mechanical properties under different water pressures and different confining pressures,and offer important reference to solve practical engineering problems.