基于离散元法的含层理砂岩细观力学特性研究  

Micromechanical characteristics of layered sandstone based on discrete element method

作　　者：吕文茂 孟凡贞 钟林华 王忠昶[2] LÜWenmao;MENG Fanzhen;ZHONG Linhua;WANG Zhongchang(Yankuang Energy Group Company Limited,Zoucheng,Shandong 273500,China;School of Traffic Engineering,Dalian Jiaotong University,Dalian,Liaoning 116028,China)

机构地区：[1]兖矿能源集团股份有限公司,山东邹城273500 [2]大连交通大学交通工程学院,辽宁大连116028

出　　处：《中国科技论文》2025年第3期207-217,共11页China Sciencepaper

基　　金：国家自然科学基金资助项目(51774199)。

摘　　要：为探究砂岩力学特性与其自身层理倾角之间的关系,通过室内单轴试验并结合离散元仿真软件——PFC(particle flow code),利用单轴压缩试验结果标定了离散元模型中的细观参数,研究了不同层理倾角下砂岩的细观力学行为与微裂纹演化特征。结果表明:随着层理倾角的逐渐增大,砂岩的弹性模量呈现出显著上升的规律,同时层理倾角对其抗压强度也具有显著影响,抗压强度呈浅“V”形变化,在层理倾角为60°时达到最低值60.1 MPa。砂岩的破坏模式随着层理倾角的变化而显现出不同特征,当层理倾角为0°和90°时,破坏主要表现为单斜面切向破裂,裂纹集中于加载区域,并沿斜向扩展;当层理倾角为30°、45°和60°时,由于层理面粘结力较弱,裂纹更倾向于沿层理面扩展,特别是在60°时,裂纹几乎完全沿层理面传播。试样破坏后,内部的微裂纹以剪切型为主,占比均超过75%,张拉型微裂纹的占比相对较低。In order to investigate the relationship between the mechanical properties of sandstone and its bedding dip angle,uniaxial compression tests conducted in the laboratory,combined with discrete element simulation soft-ware PFC(particle flow code)were empolyed to calibrate the micromechanical parameters in the discrete ele-ment model using the uniaxial compression test results.Sandstone’s micromechanical behavior and microcrack evolution characteristics under different bedding dip angles were analyzed.The results show that as the bedding dip angle increases,the elastic modulus of sandstone exhibits a significant upward trend.Meanwhile,the bedding dip angle notably impacts the uniaxial compressive strength in a shallow“V-shaped”variation manner,which reaches a minimum value of 60.1 MPa at 60°.The failure modes of sandstone also vary with changes in bedding dip angle.When the bedding dip angles were 0°and 90°,the failure is characterized by single-plane shear frac-tures,with cracks concentrating in the loading area and propagating diagonally.However,at bedding dip angles of 30°,45°,and 60°,due to the weaker cohesion of the bedding planes,cracks tends to propagate along the bed-ding planes.Specifically,the crack propagation is almost entirely along the bedding plane at the bedding angle of 60°.After failure,the microcracks within the samples were predominantly shear-type,accounting for over 75%,while tensile-type microcracks were relatively less prevalent.

关 键 词：层理砂岩 单轴压缩 裂纹扩展 颗粒流程序 力学特性 

分 类 号：U414[交通运输工程—道路与铁道工程]