赵帅 余建民 王荣彦

摘 要：【目的】深基坑工程中土体的开挖卸荷会导致土体位移变形，可能引起周围建筑物变形，因此有必要对深基坑开挖对邻近宅楼的变形影响进行分析。【方法】本研究以郑州某深基坑工程为例，在采取上部土钉墙、下部桩锚支护的联合支护方式下，使用FLAC3D对基坑的开挖过程进行数值模拟，探究不同工况下基坑开挖对周边土体和邻近建筑物的影响。【结果】研究发现：沉降量随着距基坑边缘距离的增加而减小，最终降低为零；沉降量和围护体的水平位移随着基坑开挖深度的增加而增大；邻近建筑物的沉降随着基坑开挖的加深而增大，随着距基坑边缘距离的增大而减小。【结论】本研究验证了该支护方式的可行性。

关键词：基坑开挖；桩锚支护；数值模拟

中图分类号：TU433          文献标志码：A        文章编号：1003-5168（2023）10-0063-04

DOI：10.19968/j.cnki.hnkj.1003-5168.2023.010.013

Abstract： [Purposes] The excavation unloading of soil in deep foundation pit engineering will lead to the displacement and deformation of soil， which will cause the deformation of surrounding buildings，so it is necessary to analyze the influence of deep foundation pit excavation on the deformation of adjacent residential buildings. [Methods] In this study， a deep foundation pit project in Zhengzhou was taken as an example. Under the combined support mode of upper soil nailing wall and lower pile-anchor support， FLAC3D was used to simulate the excavation process of the foundation pit， and the influence of foundation pit excavation on surrounding soil and adjacent buildings under different working conditions was explored. [Findings] It is found that the settlement decreases with the increase of the distance from the edge of the foundation pit， and finally decreases to zero. The settlement and the horizontal displacement of the enclosure increase with the increase of the excavation depth. The settlement of adjacent buildings increases with the deepening of foundation pit excavation， and decreases with the increase of distance from the edge of foundation pit. [Conclusions] This study verified the feasibility of the support method.

Keywords： foundation pit excavation; pile anchor support; numerical simulation

0 引言

随着城市化进程的不断推进，促进经济迅速发展的同时，城市人口也越来越稠密，城市建筑随之朝着高层化、地下化不断发展，因此产生了很多深基坑工程［1-2］。基坑开挖会改变初始应力场，从而引起应力重分布，使土体发生变形，若支护不当导致土体变形过大，往往会产生严重后果。因此，深基坑工程中基坑的开挖支护方式尤为重要，特别是周边有邻近建筑物或地下隧道的工程［3］。

为了保证基坑支护设计的安全可靠，一般采用数值模拟软件来模拟基坑开挖的过程［4］。近年来，许多人通过使用数值模拟来研究基坑开挖对周边土体和邻近建筑物的变形规律［5-6］，对工程实例有很大的借鉴作用。……