多次冲击荷载作用下石灰岩损伤特性与力学性能研究_中国煤炭行业知识服务平台

多次冲击荷载作用下石灰岩损伤特性与力学性能研究

Title

Study on damage characteristics and mechanical properties of limestone under multiple impact loads
作者

许光义李海艳吴磊张凯
Author

XU Guangyi;LI Haiyan;WU Lei;ZHANG Kai;
单位

河北政法职业学院建筑工程与法务系石家庄铁道大学工程力学系北京交通大学土木建筑工程学院天津大学土木工程系
Organization

Department of Construction Engineering and Legal Affairs, Hebei Vocational College of Political Science and Law
Department of Engineering Mechanics, Shijiazhuang Railway University
School of Civil Engineering,Beijing Jiaotong University
Department of Civil Engineering, Tianjin University
摘要

为研究石灰岩在多次冲击荷载作用下的安全性,采用直径为50mm的分离式霍普金森压杆装置对石灰岩试件开展不同应变率及不同冲击次数下的单轴冲击压缩试验,并结合超声波检测装置测量多次冲击荷载作用下岩体纵波波速,分析岩体纵波波速、损伤因子、峰值应力及能量耗散变化规律。结果表明:石灰岩试件纵波波速随冲击次数的增加而降低,波速降幅不断增大,损伤因子随之增大;0.25MPa冲击气压作用下试件破碎需要6次,0.35、0.40MPa冲击气压作用下试件破碎需要4次,冲击气压的增大使岩体产生破坏所用冲击次数减少;0.40MPa冲击气压第2、3、4次冲击作用下试件峰值应力降幅分别为6.23%、14.00%、25.92%,冲击作用使试件峰值应力降低,且后期冲击作用下试件应力降幅增大;冲击荷载作用下岩体能量时程曲线分为3个阶段,岩体破碎耗能密度与冲击次数之间呈现良好的二次线性正相关关系,0.40MPa冲击气压第2、3、4次冲击作用下岩体耗能密度是第1次的1.06、1.38、1.78倍,后期冲击作用对岩体的破坏作用更加显著。
Abstract

In order to study the safety of limestone under multiple impact loads. The split Hopkinson compression bar devicedecreases by 6. 23%,14. 00% and 25. 92% respectively. The impact reduces the peak stress of specimen,and the stress of the specimen decreases greatly under the later impact. The energy time history of rock mass under impact load is divided into three stages. There is a quadratic linear positive correlation between the energy consumption density of rock mass crushing and the impact times. When the impact pressure is 0. 40 MPa,the energy consumption density of rock mass under the second,third and fourth impact is 1. 06,1. 38 and 1. 78 times that of the first impact. The damage effect of impact on rock mass in the later stage is more significant.
关键词

石灰岩多次冲击荷载纵波波速损伤因子峰值应力能量耗散破碎耗能密度
KeyWords

limestone;multiple impact loads;longitudinal wave velocity;damage factor;peak stress;energy consumption;energy consumption density of crushing
基金项目(Foundation)

国家自然科学基金项目(52078032)
DOI

10.19835/j.issn.1008-4495.2023.05.010
引用格式

许光义,李海艳,吴磊,等. 多次冲击荷载作用下石灰岩损伤特性与力学性能研究[ J]. 矿业安全与环保,2023,50(5):63-69.
Citation

XU Guangyi,LI Haiyan,WU Lei, et al. Study on damage characteristics and mechanical properties of limestone under multiple impact loads[J]. Mining Safety & Environmental Protection,2023,50(5):63-69.