摘 要

地铁车站基坑开挖是地铁车站建设十分重要的构成部分，然而深基坑开挖是具有一定的复杂性与艰巨性的，其对于周边浅基础建筑结构的影响是十分大的，会造成周围的建筑物损坏以及原始环境的毁坏。在这方面，本文是根据项目的实际情况和以往的研究成果。并借助大型有限元软件进行分析，对基坑开凿挖掘过程中地下基坑的开挖尺寸、支护条件、与邻近房屋浅基础的距离、基础埋深和刚度等条件变化下的结构受力与位移进行分析研究。

(1) 基坑开凿挖掘引起邻近土体与建筑基础变形分析。根据现实的情境，建造一个有限元模拟研究模型，模拟土体性质的变化、基坑开凿挖掘尺度、建筑与基坑的间隔大小、地下连续墙的长度与刚度给邻近土体和基础横向位移以及竖向位移带来的的影响情形。得到这些因素的变化都能给基坑邻近土体与建筑基础的位移带来影响。在每一项因素给邻近土体与基础造成的变形影响水平方面看，各项因素给邻近土体和基础带来的变形影响水平最大的是建筑与基坑的间隔大小，剩余因素的影响力按顺序是开挖的尺寸、地下连续墙长度、地下连续墙刚度以及土性参数。

(2) 基坑开凿挖掘的进程中周边建筑的保护方案研究。根据研究的现实情境，建造改良支护结构体系、增加布置隔断墙、优化基坑侧面支护桩三种防备方案的有限元模拟研究模型。整体性地研究解析每一个防备方案给基坑开凿挖掘进程中建筑结构变形带来的保护作用。得出在适合的工程情况下，每个防备方案都能够减小基坑开凿挖掘给周边建筑造成影响的作用。在这之中，能够最大程度的降低建筑结构的整体变形的是改良支护结构体系，有利于降低基础的沉降差是隔断墙的建立。

关键词：地铁车站、基坑开挖、浅基础、影响

Analysis of the influence of foundation pit excavation on surrounding shallow foundation of metro station

ABSTRACT

Subway station foundation pit excavation is a very important component of subway station construction. However, deep foundation pit excavation is complicated and difficult to some extent. It has a great impact on the surrounding shallow foundation structures, causing damage to the surrounding buildings and the destruction of the original environment. In this regard, this article is based on the actual situation of the project and previous research results. With the aid of large-scale finite element software analysis, the structural stress and displacement under the conditions of excavation size, supporting conditions, distance from the shallow foundation of adjacent houses, foundation depth and stiffness during excavation of foundation pit are analyzed and studied.

1. Analysis of deformation of adjacent soil and building foundation caused by excavation of foundation pit. According to the actual situation, a finite element simulation research model is built to simulate the influence of the change of soil properties, excavation scale of foundation pit, interval between building and foundation pit, length and rigidity of diaphragm wall on the lateral displacement and vertical displacement of adjacent soil and foundation. The results show that the changes of these factors can affect the displacement of soil and building foundation near the foundation pit. In terms of the influence level of each factor on the deformation of the adjacent soil and foundation, the biggest influence level of each factor on the deformation of the adjacent soil and foundation is the distance between the building and the foundation pit, and the influence of the remaining factors is the excavation size, the length of the diaphragm wall, the rigidity of the diaphragm wall and the soil parameters in sequence.

(2) Study on the protection scheme of surrounding buildings during the excavation of foundation pit. According to the actual situation of the study, the finite element simulation research model of the three protection schemes, i.e. improving the supporting structure system, adding partition walls and arranging anti-slide piles at the bottom of the foundation pit, is established. The protection effect of each protection scheme on the deformation of the building structure during the excavation process of the foundation pit is comprehensively studied and analyzed. It is concluded that under suitable engineering conditions, each protection scheme can reduce the impact of foundation pit excavation on surrounding buildings. Among them, it is the improved supporting structure system that can reduce the overall deformation of the building structure to the greatest extent, and it is the construction of partition wall that is beneficial to reduce the settlement difference of foundation.

Key words: Subway station; Foundation pit excavation;Shallow foundation; Impact

目 录

摘要 Ⅰ

Abstract Ⅱ

1 绪论 1

1.1 研究的背景及意义 1

1.2 基坑开挖对周边影响的国内外研究现状 1

1.3 周边浅基础建筑物受基坑开挖影响分析 4

1.4 基坑开挖的施工与成果研究 7

1.5 本文主要研究内容 10

2 基坑开挖对浅基础建筑变形的影响分析 11

2.1 大型有限元软件简介 11

2.2 基坑开挖对浅基础建筑变形的影响因素 12

2.3 工程概况 13

2.4 模型的基本假定 13

2.5 模型建立及求解 13

2.6 不同参数对周边土体及建筑基础变形的影响 16

2.6.1 不同开挖尺度的影响分析 16

2.6.2 土体性质的影响分析 19

2.6.3 建筑基础与基坑距离的影响分析 22

2.6.4 支护条件的影响分析 25

2.6.5 主要影响因素确定 31

2.6 本章小结 33

3 基坑开挖过程中邻近建筑防护措施分析 35

3.1 优化基坑支护结构体系 35

3.1.1 地下连续墙深度对建筑物基础沉降影响分析 35

3.1.2 地下连续墙刚度对建筑结构基础沉降影响分析 37

3.1.3 内支撑刚度给建筑结构基础沉降造成的影响 39

3.2 隔断墙的防护措施分析 41

3.2.1 隔断墙距基坑距离给建筑物基础沉降造成的影响 42

3.2.2 隔断墙高度对建筑物基础沉降的影响 44

3.3 优化设置基坑侧面支护桩 46

3.3.1 支护桩长度对建筑物基础沉降的影响 46

3.3.2 支护桩与地连墙距离对建筑物基础沉降的影响 48

3.3.3 支护桩排数对建筑物基础沉降的影响 50