基于空孔效应的坚硬岩石涨裂破岩力学特性研究  

Research on Mechanical Characteristics of Rigid Rock Spallation and Fracturing Rock based on Empty Hole Effect

作　　者：冀玉豪 李文杰 康兰方 唐刚 梁斌 JI Yu-hao;LI Wen-jie;KANG LAN-fang;TANG Gang;LIANG Bin(School of Civil Engineering,Henan University of Science and Technology,Luoyang 471000,China;CCCC-SHEC Forth Engineering Co.,Ltd.,Luoyang 471000,China)

机构地区：[1]河南科技大学土木工程学院,洛阳471000 [2]中交二公局第四工程有限公司,洛阳471000

出　　处：《爆破》2023年第2期54-61,共8页Blasting

基　　金：国家自然科学基金项目(U1604135);中交第二公路工程局有限公司重点科技研发项目(项目编号2020-5-20);河南省科技厅产学研合作项目(2015HNCXY011)。

摘　　要：为了提高坚硬岩石定向涨裂破岩效率,从坚硬岩石涨裂定向破岩机理出发,基于空孔效应理论对200 mm、250 mm、300 mm、400 mm空孔间距以及20 mm、40 mm、90 mm、120 mm空孔半径下空孔孔壁的应力变化规律展开研究,将理论计算与数值模拟进行对比分析验证。研究结果显示:空孔的存在使得空孔靠近涨裂孔一侧产生应力集中,随着空孔间距增大、空孔半径减小,空孔效应应力集中现象越弱;空孔圆周上受拉区为±40°以内,最大拉应力出现在空孔与涨裂孔圆心连接线上,最大压应力出现在空孔圆周±70°附近。孔间连线上I型岩石应力强度因子与应力变化规律相对应,在孔间距达到400 mm时,应力强度因子K_(I)小于岩石的断裂韧度K_(IC),无法达到形成贯通裂纹的条件。依据研究成果设置空孔参数,并在深圳市铁岗-石岩水库石岩北清水引水隧洞进行涨裂破岩试验。试验结果显示:空孔对于裂纹扩展方向具有引导作用,能够促使空孔与涨裂孔连线方向产生贯通的主裂纹,有利于提高坚硬岩石的涨裂破岩效率,能够为相似工程提供借鉴和参考。In order to improve the efficiency of the directional cracking of hard rocks,starting from the mechanism of cracking from hard rocks to breaking rocks,based on the empty hole effect theory,the stress variation law of the empty hole wall under the 200 mm、250 mm、300 mm、400 mm hole spacing and the 20 mm、40 mm、90 mm、120 mm hole radius is studied,and the theoretical calculation and numerical simulation are compared and analyzed to verify.The results show that the existence of empty hole makes the stress concentration near the expansion hole,with the increase of empty hole spacing and the decrease of empty hole radius,the stress concentration of empty hole effect becomes weaker.The maximum tensile stress appears on the connection line of the empty hole and the expansion hole.The maximum pressure stress appears near the empty hole circle 70°.The stress intensity factor of type I rock on the inter-hole connection line corresponds to the law of stress variation.When the hole spacing reaches 400 mm,the stress intensity factor K_(I) is smaller than the fracture toughness K_(IC) of rock and the condition for formation of through cracks cannot be reached.According to the research results,set the parameters of the empty hole and in Shenzhen Tiegang-Shiyan reservoir Shiyan North clear water diversion tunnel to carry out the rock breaking test.The test results show that empty holes play a guiding role in the direction of crack propagation,which can cause the main crack to form on the connecting line between the empty hole and the expansion hole and is beneficial to improving the efficiency of the breaking rocks in hard rocks,which can provide reference for similar projects.

关 键 词：坚硬岩石 定向破岩 空孔效应 数值模拟 静力爆破 

分 类 号：TV542[水利工程—水利水电工程]