石质铁路隧道初期支护优化研究  

Study on primary support optimization for railway tunnel in rock

作　　者：黄海昀 仇文革[1] 黄黆[1] 李冰天 李思 田明杰 HUANG Haiyun;QIU Wenge;HUANG Guang;LI Bingtian;LI Si;TIAN Mingjie(Key Laboratory of Tunnel Engineering,Ministry of Education,School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室土木工程学院,四川成都610031

出　　处：《铁道科学与工程学报》2019年第1期152-161,共10页Journal of Railway Science and Engineering

基　　金：蒙西华中铁路股份有限公司资助项目(MHHTZX[2016]0002;TKKY201601002);国家自然科学基金资助项目(U1434206;51678497)

摘　　要：以蒙华铁路九岭山隧道为工程背景,运用强度折减法计算围岩强度储备并将其作为围岩稳定性的参考指标。依据现场监测,得到初期支护的受力特征。基于围岩强度储备指标与初期支护的受力特征,对初期支护进行优化设计,并应用于现场。研究结果表明:在围岩具有足够强度储备的前提下,初期支护主要承受形变压力;系统锚杆未发挥作用,喷射混凝土抗压性能未被充分利用,格栅钢架钢筋难以发挥其抗拉和抗弯性能;可将现有初期支护"喷射混凝土+格栅钢架+系统锚杆"的结构形式优化为"喷射混凝土+格栅钢架"。对原有设计和优化方案进行数值模拟,对比其锚杆轴力与喷射混凝土应力分布,同时应用现场试验验证该优化方案的安全性与可行性。该优化方案已在蒙华铁路应用推广。This paper took the Jiulingshan tunnel of Menghua railway as the engineering background,the strength reserve of surrounding rock was used as a reference index for the stability of surrounding rock which was calculated by the strength reduction method.The stress characteristic of primary support was obtained according to the in-site monitoring.Based on the strength reserve of surrounding rock and the stress characteristic of primary support,the primary support was optimized and applied to the site.The results show that,under the premise that the surrounding rock has sufficient strength reserve,the primary support is mainly subjected to the pressure of deformation.The systemic anchor bolts do not play an role.The compressive properties of concrete are not fully utilized.The tensile and bending behavior of the rebar in steel frames is difficult to deform.The structure of the existing primary support"shotcrete+steel frames+systemic anchor bolts"can be optimized into"shotcrete+steel frames".The original design and optimized scheme are numerically simulated,and the axial force and the stress distribution of shotcrete are compared.At the same time,the safety and feasibility of the optimized scheme are verified by in-site test.Now it has been popularized and applied in Menghua railway.

关 键 词：初期支护 围岩强度储备 现场监测 优化设计 现场试验 

分 类 号：U25[交通运输工程—道路与铁道工程]