岩石孔径分布特征对其力学性质的影响规律研究

Research on the Influence Law of the Pore Size Distribution of Rock on Its Mechanical Properties

摘要: 岩石是一种天然的多孔物质，孔隙结构会改变岩石的物理力学性质，从而影响岩石整体结构的稳定性。不同孔隙率岩石的力学性质不同，而孔隙率相同，孔径大小分布特征不同，也会对其力学性质造成影响，因此，本文着重研究孔隙率和孔径分布特征2方面对岩石单轴压缩下力学性质的影响规律，主要内容如下：1) 根据不同温度下花岗岩孔径分布结构的压汞试验结果，建立了孔隙率为2%、5%、10%，孔径分布分形维数为2、2.5、3的九种花岗岩试样的数值模型；2) 研究了不同孔径分布特征下岩石力学性质的差异，获得了孔隙率和孔径分布分形维数对岩石全应力–应变曲线、抗压强度、弹性模量、裂纹扩展路径、破坏方式等的影响规律。

Abstract: Rock is a natural porous material. Its pore structure will change its physical and mechanical properties, thus affecting the stability of the overall structure of the rock. Rocks with different porosity have different mechanical properties. The rocks with the same porosity and different distribution characteristics of pore size have different mechanical properties. Therefore, this paper focuses on the influence of porosity and pore size distribution on rock mechanical properties under uniaxial compression. The main contents are as follows: 1) Based on the mercury injection test results of the granite pore size distribution structure at different temperatures, numerical value models were established for nine granite samples with porosity of 2%, 5%, and 10%, and pore size distributions of 2, 2.5 and 3 fractal dimensions. 2) The differences in rock mechanical properties under different pore size distributions were studied, and the influence laws of the fractal dimension of porosity and pore size distribution on the stress-strain curve, compression strength, elastic modulus, crack propagation path and failure mode of the rock were obtained.