冲击动载作用下含界面裂纹岩体破坏特征试验研究  

Experimental study on failure characteristics of rock mass with interfacial cracks under impact loading

作　　者：闻磊 冯文杰[1] 李明烨 石召龙 于俊红 赵小虎 WEN Lei;FENG Wenjie;LI Mingye;SHI Zhaolong;YU Junhong;ZHAO Xiaohu(Department of Engineering Mechanics,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Hebei Research Center of the Basic Discipline Engineering Mechanics,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Hebei Polytechnic Institute,Shijiazhuang,Hebei 050091,China;PowerChina Hebei Engineering Corporation Limited,Shijiazhuang,Hebei 050021,China)

机构地区：[1]石家庄铁道大学工程力学系,河北石家庄050043 [2]石家庄铁道大学河北省工程力学基础学科研究中心,河北石家庄050043 [3]河北工程技术学院,河北石家庄050091 [4]中国电建集团河北工程有限公司,河北石家庄050021

出　　处：《岩石力学与工程学报》2024年第7期1662-1679,共18页Chinese Journal of Rock Mechanics and Engineering

基　　金：河北省自然科学基金重点项目(A2020210008);国家自然科学基金资助项目(11872257)。

摘　　要：以含预制界面裂纹的板状试样为研究对象,借助分离式霍普金森压杆系统施加不同强度的冲击动载,使用高速摄像系统记录裂纹扩展过程,分析不同冲击强度下3种界面倾角试样的宏观动态力学性质、裂纹扩展规律及破坏机制。研究结果表明,不同种类试样动态应力-应变曲线形态差别较大,在应力峰值处呈现单峰或双峰的形态,入射波峰值越小时,试样动态压缩强度受节理面角度的影响越大。根据裂纹形态、起裂位置和断裂机制共获得6种裂纹类型,随着入射能量增大,试样裂纹数量增多,试样由单一的劈裂拉伸破坏模式变为复杂的拉伸-剪切复合破坏模式。在试样界面处形成一个材料强度的“过渡区”,界面倾角以及两侧岩石弹性模量、泊松比等因素决定了“过渡区”的应力状态及强度特征。试样在预制裂纹端部首先开裂,预制裂隙端部的新生裂纹一般会跨越弱侧强化区、弱侧基体扩展,且随入射波峰值应力的增大,从Ⅰ型拉伸裂纹转变为Ⅱ型或Ⅲ型剪切裂纹,远场型裂纹相对更多的在弱侧基体出现,强侧基体一般只出现拉伸裂纹。界面和预制裂纹造成了试样复杂的应力环境和不同区域的强度条件,使得裂纹出现界面、裂尖共同主导裂纹路径的典型特征。含界面裂纹岩体破坏特征的试验研究是工程尺度层状岩体裂纹传播计算的试验基础,对于解决层状岩体工程稳定性问题具有重要意义。This study explores the macroscopic dynamic mechanical properties,crack propagation rules and failure mechanisms of plate specimens with prefabricated interface cracks.A separate Hopkinson pressure bar was used to apply impact dynamic loads of different strengths to three specimens with different interface inclination angles,and a high-speed camera system was used to record the crack expansion process.The research results show that the dynamic stress-strain curve shapes of different types of samples are quite different,showing single or double peaks at the stress peak.The smaller the incident wave peak,the greater the influence of the joint plane angle on the dynamic compressive strength of the sample.A total of 6 crack types were identified based on the crack shape,crack initiation position and fracture mechanism.As the incident energy increases,the number of cracks in the sample increases,and the sample changes from a single splitting tensile failure mode to a complex tensile-shear composite failure mode.A“transition zone”of material strength is formed at the specimen interface.Factors such as the interface inclination,the elastic modulus of the rock masses on both sides,and Poisson's ratio determine the stress state and strength characteristics of the transition zone.The sample cracks first at the end of the prefabricated crack and the new cracks will generally expand across the weak-side strengthening zone and the weak-side part.As the peak stress of the incident wave increases,they will transform from type I tensile cracks to type II or type III shear cracks.Far-field cracks appear relatively more on the weak side,while tensile cracks only appear on the strong side.The interface and prefabricated cracks create a complex stress environment and strength conditions in different areas of the specimen,making the crack interface and crack tip jointly dominate the typical crack path.Experimental research on the failure characteristics of rock masses containing interface cracks is the basis for the calculation o

关 键 词：岩石力学 动态压缩试验 层状岩体 界面裂纹 力学性质 裂纹路径 

分 类 号：TU45[建筑科学—岩土工程]