摘要
大空孔直眼掏槽技术常应用于岩巷掘进,为探究掏槽孔与空孔间距对空孔附近有效应力分布规律及掏槽效果的影响,采用数值模拟对不同孔距系数K下的单孔掏槽进行研究,分析了空孔围岩有效应力演化规律及损伤范围,并在单孔掏槽基础上研究了多孔掏槽有效应力的分布规律。研究表明:空孔对应力波具有导向作用,掏槽爆破在爆源与空孔壁的切线方向形成应力集中。当K=1.0~1.6时,单孔掏槽在孔心连线方向形成连续贯通损伤,K越小,空孔壁附近形成裂隙贯通区范围越大,但K过小使掏槽空间过小且钻孔难度也会增大,综合现场情况,建议大空孔直眼掏槽最佳K值为1.3~1.6。多孔掏槽在空孔壁附近的有效应力并非单孔掏槽有效应力的简单叠加,多孔掏槽能够避免低峰值区的出现增强掏槽效果。
Large hollow hole straight hole cutting technology is often used in rock tunnel excavation,in order to explore the effect of the distance between the cutting hole and the hollow hole on the effective stress distribution law near the hollow hole and the cutting effect,numerical simulation is used.On the basis of single-hole cutting,the effective stress evolution law and damage range of the surrounding rock of the hollow hole are analyzed,and the distribution law of the effective stress of the multi-hole cutting is studied on the basis of single-hole cutting.The research shows that the hole has a guiding effect on the stress wave,and the undercut blasting forms a stress concentration in the tangential direction between the blast source and the hole wall.When K value is between 1.0 and 1.6,single-hole undercutting forms continuous penetration damage in the direction of the connection line of the hole center.The smaller K is,the larger the range of crack penetration area is formed near the hole wall,but if K is too small,the undercutting space is too small and drilling the difficulty will also increase.Based on the on-site situation,it is recommended that the best K value for large-hole straight-hole cutting is between 1.3 and 1.6.The effective stress of the porous groove near the empty hole wall is not a simple superposition of the effective stress of the single-hole groove,and the porous groove can avoid the occurrence of low peak areas and enhance the grooving effect.
作者
蒋克文
王海亮
郭建
谷志民
缪玉松
JIANG Kewen;WANG Hailiang;GUO Jian;GU Zhimin;MIAO Yusong(School of Safety and Environmental Engineering,Shandong University of Science and Technology,Qingdao 266590,China;School of Science,Qingdao University of Technology,Qingdao 266525,China)
出处
《煤炭技术》
CAS
北大核心
2023年第7期30-34,共5页
Coal Technology
基金
国家自然科学基金项目(10672091)。
关键词
直眼掏槽
大空孔
孔距系数
有效应力
数值模拟
straight hole cutting
large hollow hole
aperture coefficient
effective stress
numerical simulation
