深埋黄土隧道系统锚杆对弹性抗力的影响分析  

Analysis of the Influence of Systematic Bolt on the Elastic Resistance of Deep-buried Loess Tunnel

作　　者：刘勇[1] 徐强 马凯蒙 LIU Yong;XU Qiang;MA Kaimeng(Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China)

机构地区：[1]石家庄铁道大学,石家庄050043

出　　处：《铁道工程学报》2020年第11期77-82,89,共7页Journal of Railway Engineering Society

基　　金：国家重点研发计划(2018YFC0808704);中铁十二局集团第四工程有限公司科研项目(201794-5)。

摘　　要：研究目的:围岩弹性抗力系数对衬砌结构的受力状态影响很大,本文从系统锚杆与围岩抗力特性的角度出发,对深埋黄土隧道系统锚杆的作用进行分析。通过对锚杆施作处围岩变形的分析,由静力等效推导出系统锚杆与弹性抗力系数的关系式,并基于现场试验与理论计算进行对比分析,对关系式进行修正,分析锚杆长度、锚杆间距、隧道开挖影响范围以及围岩的弹性模量对系统锚杆作用的影响,最后通过数值模拟进一步分析系统锚杆的作用效果。研究结论:(1)大断面深埋黄土隧道系统锚杆受压状态下,可显著提高围岩的弹性抗力系数,进而优化结构的受力,控制结构的变形,提高支护结构的安全性;(2)锚杆的长度越大,锚杆环向间距、隧道开挖影响范围和围岩弹性模量越小,受压状态锚杆对围岩弹性抗力系数的改善效果越明显;(3)围岩条件越差时,锚杆的作用效果越明显,相反当围岩条件越好,锚杆对结构的改善作用越小,可以适当地减少系统锚杆的施作;(4)本文研究方法及结论可为以后类似系统锚杆作用分析提供借鉴和参考。Research purposes:The elastic resistance coefficient of surrounding rock has a great impact on the stress state of lining structure.The function of systematic bolts in deep-buried loess tunnel was analyzed from the perspective of the resistance characteristics of bolts and surrounding rock in this study.Based on the analysis on the surrounding rock deformation at the anchorage,the relationship between bolt parameters and elastic resistance coefficients was obtained by force equivalent derivation,and then was modified by comparing field test and theoretical calculation.The influence of bolt length,bolt spacing,tunnel excavation influence scope and the elastic modulus of surrounding rock on the effect of systematic bolts was analyzed.Finally,the effect of systematic bolt was further analyzed by numerical simulation.Research conclusions:(1)When the systematic bolts in large-section deep-buried loess tunnel are in compressive,the elastic resistance coefficient of surrounding rock can be significantly improved,then the stress and deformation of structure can be optimized and controlled,and the safety of the supporting structure can be improved.(2)The improvement is more obvious when increasing the length of bolts,or decreasing the circumferential spacing of bolts,tunnel excavation influence scope and the elastic modulus of surrounding rock.(3)The worse the surrounding rock condition is,the more obvious the effect of bolt is.On the contrary,the improvement effect is smaller when the surrounding rock condition is better,and the construction of systematic bolt can be reduced appropriately.(4)The research method and conclusion can provide some reference for the analysis of similar systematic bolt action in the future.

关 键 词：弹性抗力系数 深埋黄土隧道 系统锚杆 现场试验 数值模拟 

分 类 号：U451[建筑科学—桥梁与隧道工程]