冲击荷载下层状板岩拉伸破坏及能耗规律研究  

Study on tensile failure and energy consumption law of layered slate under impact loading

作　　者：刘运思[1,2] 何楚韶 王世鸣[2] 牟天光 彭亚雄 Liu Yunsi;He Chushao;Wang Shiming;Mou Tianguang;Peng Yaxiong(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,411201,Xiangtan,China;School of Civil Engineering,Hunan University of Science&Technology,411201,Xiangtan,China)

机构地区：[1]湖南科技大学岩土工程稳定控制与健康监测湖南省重点实验室,湘潭411201 [2]湖南科技大学土木工程学院,湘潭411201

出　　处：《应用力学学报》2021年第4期1373-1382,共10页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(51704109,51604109);湖南省自然科学基金(2020JJ5179);岩土工程稳定控制与健康监测湖南省重点实验室开放基金(E22119)。

摘　　要：为探究层状板岩动态破坏机理及能耗规律,通过分离式霍普金森压杆(Split Hopkinson Pressure Bar)系统和高速摄像仪开展了巴西劈裂试验。研究了不同层理角度和加载率下板岩动态拉伸能量耗散规律以及岩体破坏模式、破坏过程与能量耗散之间的关系。通过研究得到如下主要结论:(1)随着加载率的提高,板岩动态拉伸强度和耗散能密度均呈现指数增长的趋势;(2)当层理角度θ为0°时,岩体主要是沿层理面拉伸破坏,破裂面形成破裂带,耗散能低;当层理角度θ为15°时,破裂面为剪切破裂带,而θ为30°和45°是拉剪复合破坏,两者耗散能较高;当层理角度θ为60°、75°、90°时,岩样主要是沿非层理面拉伸破坏,破裂面形成环状和中心起裂两种,耗散能最大;(3)随着加载率的提高,岩体耗散能密度越大,岩体吸收的能量越多,分形维数D值越大,岩体越破碎。In order to explore the dynamic failure mechanism and energy consumption law of layered slate,the Brazilian split test is carried out by Split Hopkinson Pressure Bar system and high-speed camera.The dynamic tensile energy dissipation laws of slate and the relationship between rock failure mode,failure process and energy dissipation under different bedding angles and loading rates are studied.The main conclusions obtained by studying this paper are as follows:Firstly,with the increase of loading rate,the dynamic tensile strength and dissipated energy density of slate all show an exponential growth trend.Secondly,when the bedding angle is 0°,the rock mass is mainly stretched and broken along the bedding plane,and the fracture surface forms a rupture zone,and the dissipation energy is low.When the bedding angle is 15°,the fracture surface is a shear rupture zone,and the bedding angles of 30° and 45° are tensile and shear composite failure,and both have higher dissipation energy.When the bedding angle is 60°,75° and 90°,the rock mass is mainly tensile failure along the non-layered surface,and the fracture surface forms two kinds of ring shape and central cracking,and the dissipated energy is the highest.Thirdly,with the increase of loading rate,the greater the dissipative energy density of rock mass,the more energy the rock mass absorbs,the larger the value of fractal dimension D and the more fractured rock mass.

关 键 词：层状板岩 冲击荷载 拉伸 破坏 能量耗散 分形维数 

分 类 号：TU45[建筑科学—岩土工程]