摘要
以新建杭绍台高铁下北山隧道为工程依托,该隧道为浅埋超大跨四线高铁路隧道,基于现场取样进行室内岩石力学试验,合理确定了不同围岩等级的力学参数,在此基础上建立三维计算模型,分析浅埋超大跨隧道采用开挖工法时的力学特性。结果表明:双侧壁导坑法在围岩位移控制方面优于三台阶法,双侧壁导坑法中上导洞加临时钢支撑的措施能有效控制位移的变化速率,优于中上导洞一次开挖的做法,设计中应注意控制拱部导洞的开挖面积;在初支结构内力控制方面,双侧壁导坑中上导洞加钢支撑的方法初支结构的拉应力最小,结构受力最为安全。
Based on the new Hangshaotai high-speed railway Xiabeishan tunnel,which is a shallow-buried,super-long-span,four-line high-speed railway tunnel,indoor rock mechanics tests are carried out on the basis of field sampling,and the mechanical parameters of different surrounding rock grades are reasonably determined,on this basis,a three-dimensional numerical calculation model is established,and the excavation method of shallow-buried and super-long-span tunnel is analyzed.The results show that the displacement control of surrounding rock by the double-sided guide tunnel method is better than that by the three-step method.The measure of adding temporary steel support to the upper guide tunnel in the double-sided guide tunnel method can effectively control the change rate of displacement,which is superior to the one-time excavation of the middle and upper guide tunnel.In the design,attention should be paid to controlling the excavation area of the arch guide tunnel;in the internal force control of the initial support structure,the steel support should be added to the upper guide tunnel in the double-sided guide tunnel.The method has the least tensile stress and the safest structural stress.
作者
于清浩
郭庆昊
王文谦
刘夏冰
Yu Qinghao;Guo Qinghao;Wang Wenqian;Liu Xiabing(China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing102600,China;School of Civil Engineering,Beijing Jiaotong University,Beijing100044,China)
出处
《能源与环保》
2019年第7期298-303,共6页
CHINA ENERGY AND ENVIRONMENTAL PROTECTION
关键词
浅埋超大跨隧道
开挖围岩响应
应力分布
围岩沉降
围岩力学参数
shallow-buried super-long-span tunnel
excavation surrounding rock response
stress distribution
surrounding rock settlement
surrounding rock mechanical parameters