冲击载荷作用下硬岩层裂破坏的理论和试验研究  

THEORETICAL AND EXPERIMENTAL STUDY OF HARD ROCK SPALLING FRACTURE UNDER IMPACT DYNAMIC LOADING

作　　者：李夕兵[1,2] 陶明[1,2] 宫凤强[1,2] 殷志强[1,2] 杜坤[1,2] 

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]中南大学深部金属矿产开发与灾害控制湖南省重点实验室,湖南长沙410083

出　　处：《岩石力学与工程学报》2011年第6期1081-1088,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展规划(973)项目(2010CB732004);国家自然科学基金资助项目(10872218;50934006)

摘　　要：理论分析半正弦冲击入射加载波形下的层裂破坏特性,推导产生层裂破坏的位置和层裂厚度。利用改进的霍普金森压杆装置产生的半正弦波形对花岗岩试件进行层裂破坏试验。采用高速摄像仪记录试件层裂破坏的全过程。试验结果表明:岩石试件在半正弦入射加载波形情况下,首先如理论推导结果一样只产生了一层层裂破坏,但是随着时间的推移,岩石试件后续又产生了多层层裂;高速摄影仪和动态应变仪所采集到的分析结果均表明后续产生的层裂是由于入射加载过程中已经对岩石试件产生了损伤,以致在很弱的残余反射波作用下继续产生破坏而出现多层层裂。因此,研究岩石等脆性材料的层裂破坏规律,不但要根据最大拉应力瞬间断裂准则分析入射加载波和反射卸载波相互作用所产生的破坏效应,而且要考虑损伤对材料的影响。理论分析和试验方法对研究岩石的层裂破坏及其他相关特性具有一定的指导意义。Through a theoretical analysis of the spalling characteristics of rocks under the impact loading of the half-sine wave incident,the location and thickness of rock spalling fracture are obtained.In the laboratory,the improved Split Hopkinson pressure bar device which produces the incident half-sine wave is applied to measure the spall characteristics of the granite specimens.The complete experimental process is recorded by a high-speed camera.Test results show that the rock specimens under the impact loading of the half-sine incident wave only produce one spalling layer initially,which is completely in accord with the theoretical analysis;and the rock specimens produce several spalling fractures with time.The analyses of both pictures from the high-speed camera and waveform recorded by dynamic strain gauges indicate that the reason of following small spalling fractures is the damages of rock specimens caused by the initial loading.For a damaged rock specimen,a very weak residual reflected wave spreading along the specimen will make it produce small spalling fractures.Hence,the investigation on the spalling characteristics of rock or other brittle materials should not only consider the dynamic tensile fracture caused by the interaction of incident and reflected waves,but also should take the influence of material damage into account.The research methodology of this paper based on the waveform theoretical analysis of the spalling characteristics and the experimental technique with high-speed camera will be helpful for the area of understanding the rock spalling process or other relevant characteristics.

关 键 词：岩石力学 硬岩 层裂 霍普金森压杆 高速摄影机 损伤 

分 类 号：TU45[建筑科学—岩土工程]