摘要
在填海造陆地层开展盾构法隧道施工时经常遇到大纵坡掘进的情况,此时开挖面的极限支护压力与水平掘进条件有所不同,同时,考虑到土仓中被动土压力情况,开挖面极限支护压力的计算会更为复杂,因此亟需对滨海地层盾构纵坡掘进被动极限支护压力的计算方法进行研究。以厦门地铁3号线双沪站-空港经济区站穿越滨海吹填砂地层为背景,基于极限分析上限法,建立了盾构纵坡掘进过程中开挖面被动稳定性分析的二维运动学破坏机制,该机制考虑了盾构隧道的纵向坡度,以及支护压力沿开挖面高度呈梯形分布对开挖面被动稳定性的影响。结果表明:盾构隧道开挖面极限支护压力随纵向坡度的增大而增大。将当前理论解与现有的上限解和数值解进行对比,发现当前理论比现有理论的计算精度分别提高了8%和26%,表明该理论方法在计算纵坡开挖面极限支护压力方面具有良好的应用前景。
When shield tunneling is carried out in the land reclamation stratum,large longitudinal slope is often encountered.At this time,the ultimate support pressure of the tunnel face is different from the horizontal conditions,and the calculation of the ultimate support pressure of the tunnel face is more complex considering the passive earth pressure in chamber.Therefore,it is urgent to study the calculation method of passive ultimate support pressure of longitudinalslope shield tunnel in coastal stratum.Based on the upper bound method of limit analysis,Shuanghu Station-Airport Economic Zone Station of Xiamen Metro Line 3 crosses the coastal hydraulic fill sand stratum as the background,this paper established a two-dimensional kinematic failure mechanism for the passive stability analysis of the excavation surface during shield tunneling.This mechanism considers the influence of the longitudinal inclination of the shield tunnel on the passive stability of the tunnel face,and considers that the support pressure is trapezoidal distributed along the height of the tunnel face.The results show that the support pressure increases with the longitudinal slope of the tunnel.Comparing the current theoretical solution with the existing upper bound solution and numerical solution,it is found that the calculation accuracy of the current theory is improved by 8%and 26%,respectively.It indicates that the theory has a good application prospect in calculating the ultimate support pressure of the longitudinal slope tunnel face.
作者
胡艳峰
钱伟丰
黄明
路遥
HU Yanfeng;QIAN Weifeng;HUANG Ming;LU Yao(CCCC First Highway Xiamen Engineering Company Co. ,Ltd. , Xiamen, Fujian 361021, China;School of Civil Engineering, Fuzhou University, Fuzhou, Fujian 350108, China)
出处
《公路工程》
2022年第2期39-48,82,共11页
Highway Engineering
基金
国家自然科学基金项目(41672290)。
关键词
盾构隧道
吹填砂
纵向坡度
被动稳定性
上限法分析
shield tunnel
hydraulic fill sand
longitudinal inclination
passive stability
upper bound analysis
