王云飞, 董贺, 马勇超,等.含平行双裂隙白砂岩力学行为数值分析[J].河南理工大学学报（自然科学版）,2024,43(3):161-170.

WANG Y F , DONG H , MA Y C ,et al.Numerical analysis of mechanical behavior of white sandstone with parallel double fissures[J].Journal of Henan Polytechnic University(Natural Science) ,2024,43(3):161-170.

含平行双裂隙白砂岩力学行为数值分析

王云飞, 董贺, 马勇超, 张意文, 袁乐乐

河南理工大学 土木工程学院，河南 焦作 454000

摘要:   目的 为探究平行双裂隙对白砂岩力学特性、裂纹扩展和能量演化的影响， 方法 利用颗粒流软件PFC2D获取白砂岩细观力学参数，通过改变双裂隙倾角和双裂隙间距2个关键影响因素，进行多次单轴压缩试验并对模拟结果进行分析。 结果 结果表明：随着裂隙倾角增大，岩石的峰值强度、弹性模量变大；随着平行双裂隙间距增大，裂隙倾角为30°时，岩石的峰值强度和弹性模量大幅降低，裂隙倾角为60°时，裂隙间距对岩石的峰值强度和弹性模量无显著影响，即裂隙间距转变为影响力学特性的次要因素；裂隙倾角对岩石的微裂纹发育过程有着重要影响，在裂纹扩展初期以拉伸裂纹为主，最终破坏形式多为剪切破坏；裂隙倾角为45°时，裂纹发育至贯通最为彻底；随着裂隙倾角增大，耗散能开始出现应变节点逐渐后移现象，岩石的弹性储能极限随之增强，裂隙倾角为0°~15°时，储能极限会发生一次小幅度反弹。 结论 双裂隙倾角和间距对白砂岩力学特性、裂纹扩展和能量演化的影响至关重要。

关键词:平行双裂隙;离散元;声发射;裂纹扩展;裂隙倾角

doi:10.16186/j.cnki.1673-9787.2023030010

基金项目:国家自然科学基金资助项目 （U1604142）；河南省重点研发与推广专项项目（212102310405）

收稿日期:2023/03/06

修回日期:2023/05/06

出版日期:2024/05/15

Numerical analysis of mechanical behavior of white sandstone with parallel double fissures

WANG Yunfei, DONG He, MA Yongchao, ZHANG Yiwen, YUAN Lele

School of Civil Engineering，Henan Polytechnic University，Jiaozuo 454000，Henan，China

Abstract:   Objectives  In order to explore the influence of parallel double fissures on the mechanical properties， crack propagation， and energy evolution of white sandstone， Methods  the particle flow software PFC2D was used to obtain the mesoscopic mechanical parameters of white sandstone. By changing the two key influencing factors of double fissure inclination and double fissure spacing， multiple uniaxial compression tests were carried out， and the simulation results were analyzed.    Results As the inclination of the fissure increases， so does the peak strength and modulus of elasticity of the rock； With the increase in parallel double fissure spacing， the peak strength and elastic modulus of the rock are greatly reduced at a fissure inclination of 30°. The fissure spacing has no significant effect on the peak strength and elastic modulus of the rock at an inclination of 60°， indicating that the fissure spacing becomes a secondary factor in influencing characteristics； The inclination of the prefabricated fracture has an important impact on the micro-crack development process of the rock， with tensile cracks being predominant in the early stage of crack expansion， and the final destruction form being mostly shear failure. When the inclination angle of the prefabricated fissure is 45°， the crack develops to its most thorough penetration； With the increase in inclination， the strain node where the dissipative energy begins to appear gradually moves backward， and the elastic energy storage limit of the rock is enhanced， with a small rebound in the energy storage limit observed in the range of 0° to 15°.   Conclusions The inclination angle and spacing of parallel double fissures have a crucial impact on the mechanical properties， crack propagation， and energy evolution of white sandstone.    

Key words:parallel double-fissure;discrete elements;acoustic emission;crack propagation;fissure dip angle