层状岩体隧道爆破对支护体系的振动影响研究  

Study on Vibration Influence of Layered Rock Mass Tunnel Blasting on Support System

作　　者：于建新[1] 刘文金 王金星[1] 刘焕春 周志彬 YU Jianxin;LIU Wenjin;WANG Jinxing;LIU Huanchun;ZHOU Zhibin(College of Civil Engineering,Henan Polytechnic University,Jiaozuo 454003)

机构地区：[1]河南理工大学土木工程学院,焦作454003

出　　处：《现代隧道技术》2023年第5期99-110,119,共13页Modern Tunnelling Technology

基　　金：国家自然科学基金项目(42107200);河南省博士后科研项目(202101036);河南理工大学杰出青年基金项目(J2023-4)。

摘　　要：为分析层状岩体隧道爆破引起的围岩稳定性问题,采用LS-DYNA数值模拟方法对不同层理倾角下隧道支护体系的动态响应特性进行研究。研究结果表明:(1)围岩层理倾角为60°时,掌子面后方25 m处拱顶水平切向峰值振速出现1.74倍的增大现象;(2)不同围岩层理倾角下左右拱腰和边墙位置处均呈现质点非对称振动特征;(3)不同层理倾角下,左右拱腰和边墙位置处水平径向和垂向峰值振速随与掌子面距离的增大呈现先减小后增大的变化趋势;(4)拱腰位置横向和竖向压应力非对称受力系数在围岩层理倾角为60°时出现明显转折,呈现先快速增大后又快速减小变化趋势;(5)随着围岩层理倾角从0°变化到90°,锚杆动态拉应力峰值呈现先增大后减小变化趋势,在隧道环向上的分布也不同。现场监测结果显示:30°围岩层理倾角下隧道爆破引起的锚固支护结构质点振动规律与研究结果具有一致性。In order to analyze the stability of surrounding rock under drilling and blasting excavation of layered rock mass tunnel,the dynamic response characteristics of the tunnel support system under different bedding angles are studied with the LS-DYNA numerical simulation method.The results show that:(1)When the bedding angle of sur⁃rounding rock is 60°,the peak vibration velocity along horizontal tangential direction of the vault at 25 m behind the tunnel face increases by 1.74 times.(2)The asymmetric vibration mechanism of particles is present at left and right hances and side walls under different bedding angles of surrounding rock.(3)The horizontal radial and vertical peak vibration velocities at left and right hances and side walls under different bedding angles show a U-shaped change trend with the increase of the distance from the tunnel face.(4)The asymmetric stress coefficients of lateral and ver⁃tical compressive stresses at the hance position show a significant turning point when the bedding angle of the sur⁃rounding rock is 60°,showing a trend of rapid increase at first and then rapid decrease.(5)As the bedding angle of surrounding rock layer changes from 0°to 90°,the peak dynamic tensile stress of the bolt shows a trend of increase at first and then decrease.The circumferential distribution of the peak dynamic tensile stress of the bolt shows incon⁃sistency with the change of the bedding angle of surrounding rock.The on-site monitoring results show that the par⁃ticle vibration law of the anchor support structure caused by tunnel blasting at a 30°bedding angle of surrounding rock is consistent with the research results.

关 键 词：层状岩体 隧道爆破 支护体系 数值模拟 振动监测 

分 类 号：U451[建筑科学—桥梁与隧道工程]