基于极限上限法的富水复合地层盾构隧道开挖面极限支护力计算方法
A Calculation Method for Ultimate Support Force of Excavation Face of Shield Tunnels in Water-Rich Composite Strata Based on Upper Limit Method
李垂忝 1刘彦辉 1卢清碧 2况彦 2朱志良 2胡子威3
作者信息
- 1. 南昌轨道交通集团有限公司地铁项目管理分公司,江西 南昌 330200
- 2. 中建三局集团有限公司,湖北 武汉 430075
- 3. 中南大学土木工程学院,湖南 长沙 410075
- 折叠
摘要
为更合理地设置富水复合地层盾构隧道开挖面支护力,保障盾构隧道安全掘进,基于极限上限法分析原理和相关联流动法则,构建水平层状地层盾构隧道开挖面分段对数螺旋线破坏机构,建立多层水平层状富水地层盾构开挖面稳定性极限上限法分析和极限支护力计算方法,并开展参数分析;并进一步依托实际工程,将理论计算方法、数值模拟与工程实践测试进行对比.结果表明:1)从隧道底部自下而上,土体参数对极限支护力的影响不断减小;2)与传统的地层均质化处理方法相比,考虑地层分层的破坏机构能够较好地表达多层复合地层盾构开挖面的破坏机制;3)考虑开挖面的变形控制,推荐将本文计算结果乘以 1.5 倍的安全系数作为土舱压力值.
Abstract
The rational setting of excavation face support pressure is a prerequisite for ensuring the safe advancement of shield tunneling and maintaining excavation face stability.Based on the analysis principle of limit and upper limit method and associated flow law,the segmented logarithmic helix failure mechanism of horizontal stratified shield tunnel excavation face is constructed,the limit and upper limit method of stability analysis and limit support force calculation of multilayer horizontal stratified water-rich stratum shield excavation face are established,and the parameters are analyzed.Furthermore,based on an actual engineering project,the results of theoretical calculations,numerical simulations,and practical tests are compared.The findings indicate that:(1)The influence of soil parameters on the ultimate support pressure decreases from tunnel bottom to top.(2)Compared to the traditional homogenization method,considering the stratification of layers provides a better representation of the failure mechanism in the excavation face of a shield in multilayer composite soil.(3)For deformation control of the excavation face,it is recommended to multiply the calculated results in this study by a safety factor of 1.5 as the soil chamber pressure.
关键词
盾构隧道/极限支护力/富水复合地层/极限上限法Key words
shield tunnel/ultimate support force/water-rich composite strata/upper limit method引用本文复制引用
基金项目
江西省高层次高技能领军人才培养工程()
中国建筑第三工程局科技研发项目()
出版年
2024
NETL
NSTL
万方数据