洞桩法隧道边桩参数对变形规律的影响研究

Influence of Parameters on Lateral Displacement of Piles in Tunnels Using PBA Method

洞桩法地铁站隧道中边桩的横向变形是重要的力学效应之一。采用模型试验和数值模拟方法,分析了边桩的直径、间距、桩底埋置深度等参数对桩身横向变形规律的影响。研究结果表明:增大桩径和减小桩间距都能有效减小桩身横向位移,而桩底埋置深度加深对桩身横向位移影响不显著,其取值主要应考虑边桩的整体稳定性和竖向承载能力;在相同控制位移要求下,增大桩径对最大横向位移的控制效果优于减小间距对位移的控制效果。

Lateral displacement is one of the important mechanical characteristics of the piles in tunnels using PBA （Pile-beam-arch） method. The influences of parameters, such as piles spacing, section diameter and buried depth, on lateral displacement of piles are investigated using model test and numerical simulation. The results show that magnification of section diameter and piles spacing can both diminish the lateral displacement of piles. The extending of buried depth of piles is not obviously taking effect to the diminishing of lateral displacement. Buried depth is mainly up to stability and vertical hearing capacity. Enlarged section diameter is preferable to shrunk piles spacing to the same request of diminishing the lateral displacement of pile.