摘要
针对怀邵衡岩鹰鞍隧道F4断层段施工,围岩破碎、富水、易变形的问题,通过数值模拟分析了三台阶四步法进行开挖时,不同循环进尺长度、不同施工步之间错距长度对隧道围岩的位移变形和支护结构力学特性的影响.研究结果表明:隧道围岩变形对循环进尺的长度最为敏感,相较于错距长度改变所引起的围岩变形量,前者比后者高出3~4倍;加强开挖段中部的钢支撑强度、准确把握支护时机,以抵抗暴露围岩的变形.因此,在软弱断层隧道开挖过程中,隧道施工安全性应首先考虑循环进尺取值,其次考虑台阶错距长度以保证隧道施工便捷性及安全性.此研究成果可为类似工程提供参考和依据.
In view of the problems in F4 fault section of Yanyingan Tunnel in Huaishaoheng Railway, including the broken surrounding rock, rich water, easy deformation, the influence on mechanical characteristics was analyzed with numerical simulation about the supporting structure and the displacement and deformation of surrounding rock, in the aspects of different circular footage length and staggered distance length between different construction step by three-bench and four-step method. The results showed that the surrounding rock deformation of the tunnel was most sensitive to the length of circular footage, with comparison of the surrounding rock deformation caused by the change of stagger length, the former is 3 ~ 4 times higher than the latter, the steel support should be strengthened and the supporting opportunity should be accurately controlled in the middle of excavation section to resist the deformation of exposed surrounding rocks. Therefore, in the process of soft fault tunnel excavation, the cyclic footage should be taken into account first and the staggered distance length secondly, so as to ensure the safety of tunnel construction. This research result could provide reference for similar projects.
作者
张旭辉
Zhang Xuhui(China Railway 20th Bureau Group Co. Ltd., Xi'an Shaanxi 710016, China)
出处
《铁道建筑技术》
2019年第9期107-109,127,共4页
Railway Construction Technology
基金
湖南省科技计划项目经费资助(2017SK2393)
关键词
三台阶四步法
F4断层
循环进尺
错距长度
围岩变形
数值模拟
three-bench and four-step method
F4 fault
circular footage length
staggered distance length
surrounding rock deformation
numerical simulation
作者简介
张旭辉(1977-),男,江西丰城人,高级工程师,主耍从事隧道与地下工程技术与管理工作,E-mail:812691013@qq.com.
