水闸深基坑开挖对紧邻桥梁桩基的影响分析

摘要

Based on the deep foundation pit of Maluanwan sluice in Xiamen ,the near bridge is located in the excavation area of the pit .The lower structure of the bridge is a bored-pile foundation ,so the excavation and dewatering will have a significant impact on the pile foundation .For evaluating the additional deformation of adjacent bridge piles ,the geotech-nical finite element analysis software is used to simulate the process of excavation .Considering the soil behaviors and the interaction between the piles and soil ,Hardening-Soil model is adopted ,and the excavation model is set up .The behav-iors of the deflection and bending moments of piles are studied detailedly ,and the effects of many factors on the behaviors of adjacent piles are investigated ,including the net distance between excavation and pile ,stiffness of pile ,stiffness of di-aphragm wall ,constraint conditions of pile head ,and dewatering .This study suggests that the excavation and dewatering have significant influence on the adjacent piles .%以厦门马銮湾水闸深基坑工程为研究对象，邻近大桥位于水闸深基坑开挖区域之中，下部结构为钻孔桩基础，基坑开挖降水对该桩基础会造成显著影响，为评估紧邻桥梁桩基产生的附加变形，采用土工有限元分析软件，考虑桩土相互作用，建立基坑开挖模型，土体采用 HS 模型模拟，深入分析桩身水平位移和弯矩的变化特性，并研究了基坑降水开挖时基坑与紧近桩基的间距、桩基刚度、支护刚度、桩头约束以及降水等各种影响因素。研究表明：基坑的开挖降水对紧邻桥桩的影响效应明显。