摘要
随着断面跨度的不断增大,公路隧道设计开挖方式也在不断转变。同三、京珠国道主干线绕广州公路东环段龙头山隧道属单洞四车道特大断面公路隧道,进出口Ⅴ级围岩段地质条件恶劣,采用双侧壁导坑法施工。在龙头山隧道的施工过程中,其核心土临时支护出现失稳。通过简化临时支护稳定的影响因素,建立力学平衡方程,推导出核心土临时支护稳定性的判别准则,开挖上台阶时临时支护稳定性的控制因素为基底围岩承载力与临时支护曲率,并通过算例计算了Ⅴ级围岩临时支护设计曲率条件下满足龙头山隧道临时支护安全要求的基底承载力的要求,在同类工程中有较大的应用价值。
The construction method is contionuously developed with the augment of the tunnel section.Longtoushan Mountain tunnel,which belongs to the Guangzhou east-ring segment of Tongsan,Jingzhu national highway,is a four-lane large section highway tunnel.The geological condition of the rock at the intake and exit of the tunnel is of grade V.In this section,the double-side-wall heading construction method has been adopted.The temporary support of core soil had been failed in this tunnel.The stability of the temporary support has been studied.The influential factors have been predigested to establish mechanical equations.Based on the boundary condition,the stability criterion of the temporary support has been set up.The controlling factors of the stability of the temporary support during the excavating of the upper bench include the bearing capacity of the basement and the curvature of temporary support.An example about calculating the requirement of the bearing capacity of the basement of Longtoushan Mountain Tunnel with the grade V rock and the design curvature of the temporary support has been given.The criterion can be used in similar projects.
出处
《地下空间与工程学报》
CSCD
北大核心
2010年第4期701-706,728,共7页
Chinese Journal of Underground Space and Engineering
基金
交通部西部交通建设科技项目成果推广项目(2007-318-799-80)
关键词
大跨隧道
双侧壁导坑法
核心土临时支护
稳定性
large cross section tunnel
twin sidewall drift method
temporary support of the core rock pillar
stability
