大直径中空孔直眼掏槽爆破的空孔应力集中效应研究  

Study on Stress Concentration Effect of Large-Diameter Empty Hole in Burn Cut Blasting

作　　者：孟海利 孙鹏昌 薛里 康永全 MENG Hai-li;SUN Peng-chang;XUE Li;KANG Yong-quan(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;State Key Laboratory for Track Technology of High-Speed Railway,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中国铁道科学研究院集团有限公司高速铁路轨道技术国家重点实验室,北京100081

出　　处：《爆破》2023年第4期60-65,153,共7页Blasting

基　　金：中国铁道科学研究院集团有限公司院基金课题重点项目(2021YJ066);北京市科协青年人才托举工程项目(BYESS2022219)。

摘　　要：为了探明大直径中空孔直眼掏槽爆破的力学机理,采用理论分析和数值模拟方法研究了大直径中空孔直眼掏槽爆破的空孔应力集中效应。建立了空孔应力集中效应的力学模型,基于弹性力学和波动力学理论阐明了空孔应力集中效应的力学机理;开展了典型工况下大直径中空孔直眼掏槽爆破的数值模拟,并基于应力波传播、岩体损伤和岩体第一主应力峰值等结果分析了空孔的应力集中效应。研究结果表明:空孔应力集中效应主要源自孔洞应力集中效应和应力波叠加效应;大直径中空孔直眼掏槽爆破过程中,应力波在空孔壁处发生反射并与入射波产生叠加,叠加多位于空孔邻近区域以及掏槽孔间区域;岩体损伤程度较高的区域主要为掏槽孔周边、空孔周边以及相邻掏槽孔与空孔形成的三角区域,掏槽孔周边以外的损伤区域与应力波叠加区域基本对应;空孔附近存在显著的应力集中效应,且距空孔壁越近的位置应力集中效应越明显。研究成果拟为隧道工程大直径中空孔直眼掏槽爆破设计提供理论基础。To explore the mechanical mechanism of burn cut blasting with a large-diameter empty hole,the stress concentration effect of the large-diameter empty hole was studied by theoretical analysis and numerical simulation.Firstly,a mechanical model for the stress concentration effect of the empty hole was established.Furthermore,the empty hole′s stress concentration effect was clarified based on the elasticity theory and wave dynamics.A numerical simulation under a typical working condition was then carried out,and finally the stress concentration effect of the empty hole was investigated based on the numerical results of stress wave propagation,rock damage,and the first principal stress.The results show that the stress concentration effect of the empty hole is mainly derived from the stress concentration around the cavity and the stress wave superposition effect.During the blasting process,the stress wave is reflected at the empty hole wall and superposed with the incident wave,which is mostly located in the vicinity of the empty hole and the region between the cut holes.The regions with high damage degree are mainly around the cut hole,near the empty hole,and within the triangle regions formed by adjacent cut holes and the empty hole,and the latter two regions correspond to the stress wave superposition regions.There is a significant stress concentration effect near the empty hole,and the closer the rock is to the empty hole,the more obvious the effect is.

关 键 词：隧道工程 掏槽爆破 数值模拟 应力集中效应 中空孔 

分 类 号：U25[交通运输工程—道路与铁道工程]