冲击荷载作用下岩石动态响应预测研究  

Prediction of dynamic response of rock under impact loads

作　　者：刘杰[1] 冯世国 李天斌[2] 王瑞红[1] 雷岚[1] 王飞[1] LIU Jie;FENG Shi-guo;LI Tian-bin;WANG Rui-hong;LEI Lan;WANG Fei(Key Laboratory of Geological Hazards in Three Gorges Reservoir Area,Ministry of Education,China Three Gorges University,Yichang 443002,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《岩土工程学报》2018年第11期2022-2030,共9页Chinese Journal of Geotechnical Engineering

基　　金：成都理工大学地质灾害防治与地质环境保护国家重点实验室开放基金(SKLGP2016K023);国家自然科学基金项目(51439003,51579138,51479102);湖北省教育厅项目(D20161202);湖北省杰出青年人才计划项目(2018CFA065);三峡大学硕士学位论文培优基金(2018SSPY024)

摘　　要：利用已有大理岩对冲击波的动态响应图,验证在0.1Hz不同加载方式下提出的岩石非线性动态响应预测模型及预测公式的适用性和合理性,提出加载速率波形曲线函数的适用条件。经研究表观弹性模量的拟合系数,提出了冲击压实系数a和冲击初始弹性模量b,以及岩样内部裂隙孔洞的压密效应系数a1和滑移错动效应系数a2,且有a=a1＋a2,a1〉0,a2〈0。指出当岩样受到荷载作用时,岩样的压密作用与滑移错动作用是同时存在的,在加载段,｜a1｜〈｜a2｜,在卸载段,｜a1｜〉｜a2｜,致使加载段a〈0,卸载段a〉0。定义了加卸载速率响应比β,表征卸载段平均切线模量与加载段平均切线模量的比值,β值越大岩石的破坏程度越大,不同频率下,砂岩在三角波和正弦波加载方式下均有β≈2。各应变片的应变、变形速率、能量值的实测值与计算值均吻合较好,证明了在低速荷载下提出的岩石非线性动态响应预测模型及预测公式在高速冲击波随时间的毫秒级变化规律情况下具有较好的适用性和合理性,拓宽了该预测公式和模型的应用范围,对位移控制严格的工程设计和施工有现实意义。The existing dynamic response diagram of marble to shock waves is used to verify the applicability and rationality of prediction model and prediction formula for the nonlinear dynamic response of rock under low velocity loading. The applicable conditions of the loading rate waveform function are proposed. Based on the study of the apparent elastic modulus of the fitting coefficient,the impact compaction coefficient a and the impact initial elastic modulus b,as well as the compaction action a1 and slip action a2 of the fractured voids in a rock sample, are proposed, and a=a1＋a2,a10,a20. When it is subjected to the action of loads, the compaction degree of the rock sample and slip action exist simultaneously. In the loading section,｜a1｜｜a2｜,and in the unloading section, ｜a1｜｜a2｜. That causes a0 in the loading stage and a0 at the unloading section. The loading-unloading rate response ratio β,which represents the ratio of the average tangent modulus of the unloading section to the average tangent modulus of the loading section, is defined. As the value of β increases, the degree of rock damage is also greater. At different frequencies, the sandstone has β≈2 in the loading mode of triangular waves and sine waves. The measured values of strain, deformation rate and energy value of each strain gauge are in good agreement with the calculated ones. It is proved that the nonlinear dynamic response prediction model and prediction formula for rock under low velocity loads have good applicability and rationality in the case of high-speed shock waves with millisecond time variation, which broadens the application range of the prediction formula and model. It is helpful to the designand construction of the project with strict displacement control.

关 键 词：冲击波 动态响应 拟合系数 加卸载速率响应比 预测公式 

分 类 号：TU45[建筑科学—岩土工程]