泥水平衡盾构掘进对邻近桩基的影响

Influence of Slurry Balance Shield Tunneling on Adjacent Pile Foundation

基于某泥水盾构隧道施工为工程背景,通过有限元软件建立三维数值模型,结合现场监测结果,研究了泥水盾构隧道穿越桩基过程中对桩基的影响。研究表明,当桩基距隧道同样的水平距离时,桩基埋深对桩的水平位移有一定程度的影响。不同泥水压力对桩基水平和竖向位移均有显著影响。泥水压力越大,桩基变形影响范围越大,桩基的水平和竖向位移也越大。隧道掘进会引起地层损失,从而造成桩基产生位移。不论L/H(桩长/隧道埋深)大小,桩身水平位移峰值均随着地层损失率的变大而变小,当地层损失率为0.28/%(泥水压力为332kPa)时桩身水平位移峰值最小。

Based on the construction background of a mud-water shield tunnel,a three-dimensional numerical model was established by finite element software,and combined with the field monitoring results,the influence of mud-water shield tunnel on pile foundation was studied.The research shows that when the pile foundation is the same horizontal distance from the tunnel,the buried depth of the pile foundation has a certain influence on the horizontal displacement of the pile.The horizontal and vertical displacement of pile foundation are significantly affected by different mud pressure.The larger the mud-water pressure is,the larger the influence range of pile deformation is,and the larger the horizontal and vertical displacement of pile foundation is.Stratum loss will be caused by tunneling and pile displacement will result.Regardless of the size of L/H(pile length/tunnel depth),the peak value of pile horizontal displacement decreases with the increase of formation loss rate,and the peak value of pile horizontal displacement is the minimum when the stratum loss rate is 0.28/%(mud-water pressure is 332kPa).