文献类型：期刊文献

中文题名：饱水冻结花岗岩动态力学性状的应变率效应

英文题名：Strain Rate Effect of Dynamic Mechanical Characteristics of Saturated Freezing Granite

作者：王建国 雷振 杨阳 李祥龙 郭延辉

第一作者：王建国

机构：[1]云南农业大学建筑工程学院;[2]昆明理工大学国土资源与工程学院;[3]贵州理工学院矿业工程学院;[4]云南农业大学水利学院

第一机构：云南农业大学建筑工程学院,昆明650201

年份：2018

卷号：14

期号：5

起止页码：1292-1297

中文期刊名：地下空间与工程学报

外文期刊名：Chinese Journal of Underground Space and Engineering

收录：CSTPCD;;北大核心:【北大核心2017】；CSCD:【CSCD2017_2018】；

基金：国家自然科学基金(51664007;51564027);云南省科技厅基础研究青年项目(2016FD029);云南省教育厅科学研究基金(2016ZZX108)

语种：中文

中文关键词：冻结花岗岩;应变率效应;SHPB;动力响应;能量耗散;损伤

外文关键词：frozen granite;strain rate effect;Split Hopkinson Pressure Bar;dynamic response;energy dissipation;damage

摘要：从某场地钻取典型花岗岩岩芯试样,借助75 mm直径SHPB装置和低温冻结设备,分别对-15℃和25℃饱水花岗岩试件施加应变率大小近乎相等的4种冲击荷载,以探究饱水冻结花岗岩动力学特性的应变率效应。试验结果表明:同等应变率冲击加载下,饱水冻结花岗岩的峰值强度更高,抗剪切强度增加,动态弹性模量变为近似直线型增长;相比25℃饱水花岗岩,-15℃饱水冻结花岗岩破坏需要更高的冲击应变率,破坏时的峰值应变减小。饱水冻结花岗岩内部复合结构裂纹的形成与耗散能紧密相关,耗散能越大,裂纹越多,用耗散能表征的损伤变量值可以判断岩石的破碎程度,-15℃冻结饱水花岗岩破坏时的损伤变量值为0.22。研究方法为确定高寒地区冻结岩体的动力学参数提供依据。
In order to study the dynamic characteristics of granite under complex environment,a typical granite core sample was drilled from a site. The dynamic mechanical tests were conducted under different strain rates on fully saturated granite under the temperature of-15℃ and 25℃ with a Φ75 mm SHPB device and cryogenic equipment.Then the strain rate effect on the dynamic characteristics of the frozen granite were analyzed. The test results show as follows：（ 1） Under the load of equal strain rate,the peak strength of the frozen granite was higher,the shear strength increased,and the growth patterns of dynamic elastic modulus changed to approximate linear.（ 2） To compare with25℃ saturated granite,the destruction of-15℃ saturated frozen granite requires a higher impact strain rate but low peak strain.（ 3） Impact incident energy is mainly used for breaking the original structure and freezing effect of frozen granite to form internal cracks. The formation of the crack is closely related to the dissipation energy. The larger the dissipation energy,the more the cracks,the value of the damage variable represented by the dissipation energy can determine the fracture degree of the rock. The damage variable value is 0.22 of saturated frozen granite under-15℃temperature state. The research method provides the basis for determining the dynamic parameters of frozen rock mass in high cold region.