摘要
采用有限元数值模拟分析技术,研究因隧道开挖施工而引起周围土体及不同位置单桩的变形规律。在分析中考虑了不同位置单桩和桩—土相互作用的影响。系统数值试验研究成果显示:(1)地铁开挖对上部桩土沉降影响明显,引起桩两侧的明显沉降变形差,使桩土可能产生负摩阻力或分离—临洞侧丧失摩阻力。(2)由于左侧桩的存在使隧道两侧土体的刚度明显不对称,故隧道开挖引起有桩侧向洞内的水平位移远小于无桩侧,且随着桩长增加,这一差异增大。(3)地铁开挖引起短桩以刚性倾斜为主的变位,引起长桩以挠曲为主的变位。(4)地铁开挖对洞周桩土的变形影响可分为4个不同影响区,A区桩土主要以整体下沉变形为主;B区以明显的不对称变形为主要特点,且在桩底会产生一定的压缩刺入变形,沉降量较其余三个区均大;C区特点与B区相似,但沉降量明显减小;D区几乎不受开挖影响。对洞周土体进行了分区,总结了桩端在不同区内时对周围土体位移及桩变形的影响规律,为评定地铁建设对于周围环境的影响提供参考依据。
Numerical analysis is performed to study the features of ground and pile deformations caused by tunneling in the vicinity. The influences of pile position and soil-pile interaction are considered, and the numerical results indicate： 1） The induced ground settlement at the near-tunnel side of the pile is much smaller than that at the other side of the pile, which might cause unbalanced frictions on the pile shaft; 2） The ground horizontal movement around the tunnel is unsymmetric, due to the stiffness effect of the pile; 3） For short piles, tilting is the major form of pile deformation, while for long piles, bending is the major form of pile deformation, as effected by nearby tunneling; 4） Based on deformation behavior, the surrounding soil of the tunnel is categorized into four different zones, to understand better the influence of tunneling to nearby pile foundations.
出处
《土木工程学报》
EI
CSCD
北大核心
2006年第10期107-111,共5页
China Civil Engineering Journal
关键词
地铁
隧道
单桩
数值分析
土体位移变化
桩的变形
subway
tunnel
single pile
numerical analysis
soil movement
pile deformation
