砂岩单轴压缩力学特性试验及数值模拟研究

Experimental and Numerical Simulation Study on Mechanical Properties of Sandstone Under Uniaxial Compression

为分析不同冻结温度下砂岩的力学特性,采用伺服试验机对砂岩试样进行单轴压缩,运用FLAC3D软件模拟砂岩破坏过程,详细分析了不同温度和不同粒径下各特征应力及位移变形。结果表明:砂岩应力峰值强度随试样温度的升高逐步降低,相同条件下,中粒、粗粒砂岩峰值强度应力差值随温度的增大逐渐减小,中粒、粗粒砂岩应力差值最大达19 MPa;数值模拟砂岩单轴压缩破裂过程应力集中区域,破坏时应力集中区域面积约为12 mm2;砂岩压缩呈三点式位移变形,随加载步数增加,三点式变形区域贯通连接成片导致岩石破坏。

In order to analyze the mechanical properties of sandstone under different freezing temperatures,a servo testing machine is used to perform uniaxial compression on sandstone samples,and FLAC3D is used to simulate the failure process of sandstone.The characteristic stresses and displacement deformations at different temperatures and particle sizes are analyzed in detail.The results show that the peak stress intensity of sandstone gradually decreases with the increase of sample temperature;under the same conditions,the difference in peak stress intensity between medium and coarse grained sandstone gradually decreases with the increase of temperature,and the maximum difference in stress between medium and coarse grained sandstone is 19 MPa;numerical simulation of the stress concentration area in the process of uniaxial compression fracture of sandstone,the area of the stress concentration area is about 12 mm2 when the sandstone is damaged;the compression of sandstone exhibits a three-point displacement deformation,and as the number of loading steps increases,the three-point deformation area is connected and connected into pieces,leading to rock failure.