单轴压缩下饱和裂隙红砂岩力学特性试验及PFC^(2D)模拟  

Mechanical properties test and PFC^(2D) simulation of saturated fractured red sandstone under uniaxial compression

作　　者：孙杰龙 陈锐 李晓敏 邱明明 曹雪叶 王银 SUN Jielong;CHEN Rui;LI Xiaomin;QIU Mingming;CAO Xueye;WANG Yin(School of Architecture and Civil Engineering,Yan’an University,Yan’an 716000,China)

机构地区：[1]延安大学建筑工程学院,陕西延安716000

出　　处：《延安大学学报（自然科学版）》2024年第4期114-120,共7页Journal of Yan'an University：Natural Science Edition

基　　金：国家自然科学基金资助项目(12102379,12462032);陕西省大学生创新创业训练计划项目(S202310719061);延安大学十四五中长期重大科研项目(2021ZCQ011)。

摘　　要：为研究饱和状态下裂隙红砂岩力学特性,对不同预制裂隙角度的饱和红砂岩进行了单轴压缩试验和PFC^(2D)数值模拟,结果表明,单轴压缩下饱和裂隙红砂岩变形可划分为五个阶段:孔隙压实阶段、弹性变形阶段、新裂纹产生和生长阶段、岩样裂纹发展加速阶段和断裂失稳阶段。在不同角度下,应力和应变均随着角度的增大逐渐增大,且试样破坏类型以剪切破坏为主。试样损伤程度随着角度逐渐增大,裂隙对试样的损伤呈现出先增大后减小的趋势,其中在45°时裂隙对试样的损伤最大。数值模拟结果表明模拟所得试样主要破坏形式与试验试样破坏形式相同,均为剪切破坏,裂纹主要分布于裂隙上下两个尖端,且以剪切裂纹为主,伴有少量拉伸裂纹。研究结果对富水地区地下岩柱稳定性的评价具有参考价值。In order to study the mechanical properties of fractured red sandstone under saturated conditions,uniaxial compression test and PFC^(2D)numerical simulation are carried out on saturated red sandstone with different prefabricated fracture angles.The results show that the deformation of saturated fractured red sandstone under uniaxial compression can be divided into five stages:pore compaction stage,elastic deformation stage,new crack generation and growth stage,rock sample crack development acceleration stage and fracture instability stage;At different angles,the stress and strain increase gradually with the increase of the Angle,and the failure type of the sample is mainly shear failure.With the increasing of the sample damage degree,the fracture damage to the sample showed a trend of first increasing and then decreasing,and the fracture damage to the sample was the largest at 45°.The numerical simulation results show that the main failure mode of the simulated sample is the same as that of the test sample,which is shear failure.The cracks are mainly distributed in the upper and lower tips of the cracks,and the shear cracks are mainly accompanied by a small amount of tensile cracks.The research results are of reference value for evaluating the stability of underground rock pillars in water-rich areas.

关 键 词：单轴压缩 裂隙红砂岩 损伤特性 PFC^(2D) 

分 类 号：TU458[建筑科学—岩土工程]