孔洞形状对层状岩石力学特性影响的FDEM数值模拟研究  

Effect of hole shapes on mechanical behavior of layered rocks using FDEM numerical method

作　　者：刘平 刘泉声[1] 夏明锬[2] 罗勇 陈梓韬 黄兴[4] 伯音 LIU Ping;LIU Quansheng;XIA Mingtan;LUO Yong;CHEN Zitao;HUANG Xing;BO Yin(School of Civil Engineering,Wuhan University,Wuhan 430072,China;China Railway No.11 Construction Bureau Group Co.Ltd.,Wuhan 430072,China;The 5th Engineering Co.Ltd.,China Railway 11th Bureau Group,Chongqing 400030,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430072,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]中铁十一局集团有限公司,湖北武汉430072 [3]中铁十一局集团第五工程有限公司,重庆400030 [4]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430072

出　　处：《中南大学学报（自然科学版）》2024年第2期595-606,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(U21A20153);湖北省重点研发计划项目(2021BCA133);中铁十一局集团有限公司科技创新项目(22-AI-06)。

摘　　要：为揭示孔洞形状对层状岩石力学性质和破坏模式的影响,采用有限元-离散元耦合数值模拟方法(FDEM)开展系列数值模拟研究。首先,阐述FDEM模拟层状岩石的基本原理,然后,开展不同层理倾角完整试样的单轴压缩模拟,并与试验结果进行对比验证。最后,对含有圆形、椭圆形、三角形、矩形和方形孔洞的层状岩石试样(β为0°、30°、45°、60°和90°)进行单轴压缩模拟研究。研究结果表明:对于不同孔洞形状的试样,抗压强度和试样破坏程度随层理倾角的增大呈V字型变化趋势,且均在层理倾角为0°时抗压强度取得最大值,在90°时破坏程度最为严重;孔洞的存在严重削弱了试样的力学性能,且削弱幅度与孔洞形状密切相关,其中方形和圆形孔洞对抗压强度的削弱能力最弱。将含不同形状孔洞试样的破坏模式随层理倾角的变化主要分为穿层理面拉剪混合破坏(β=0°)、沿层理面与穿层理面混合拉剪破坏(β=30°)、沿层理面剪切破坏(β=45°和60°)和沿层理面拉剪劈裂破坏(β=90°)。To reveal the influence of hole shapes on the mechanical behaviors and failure modes of layered rocks,a series of numerical simulations were carried out using the combined finite-discrete element method(FDEM).Firstly,the basic principle of FDEM simulation of layered rocks was introduced,and then the uniaxial compression simulation of intact samples with different foliation angles was carried out,and compared with the experimental results.Finally,a series of uniaxial compression simulations were carried out for layered rock samples(β=0°,30°,45°,60°,and 90°)with circular,elliptical,triangular,rectangular,and square holes.The results show that for samples with different hole shapes,the compressive strength and the damage degree of samples show a V-shaped change trend with the increase of foliation angles,and the compressive strength reaches the maximum when the foliation angle is 0°,and the damage degree is the most serious when it is 90°.The existence of holes seriously deteriorates the mechanical properties of the samples,and the weakening extent is closely related to the shape of holes.The weakening ability to compressive strength of square and circular holes is the weakest.The failure modes of samples containing holes with different shapes are mainly divided into tensile-shear mixed failure across the bedding plane(β=0°),tensile-shear mixed failure along the bedding plane and across the bedding plane(β=30°),shear failure along the bedding plane(β=45°and 60°)and tensile-shear splitting failure along the bedding plane(β=90°).

关 键 词：有限元-离散元耦合数值模拟方法 层状岩石 孔洞形状 单轴压缩模拟 力学性质 

分 类 号：TU458[建筑科学—岩土工程]