摘要拟建工程位于苏州市平江区苏站路以北、芳草路以东地块，拟建项目南侧为苏州市火车站，西侧为在建的苏站路以北广场，北侧为和合街，距西侧规划地铁4号线最近处约130m，距东侧规划地铁2号线最近处约120m，交通便利，地理环境优越。52536

本基坑开挖范围25200平方米，开挖深度11.9m,东西南侧场地开阔，北侧用地范围较小，用地范围明显不允许全部放坡，全用灌注桩加支撑花费较高，出于经济方面的考虑，可以适当在上面部分采取放坡加打土钉的方式，整个基坑在下面部分采用一排钻孔灌注桩作挡土结构, 钢筋混凝土内支撑作为支撑结构体系。基坑四周采用深层搅拌桩作止水帷幕。基坑内采用深井井点降水。

毕业论文关键词： 支护结构、挡土结构、 钢筋混凝土支撑、钻孔灌注桩

Abstract The project is located in the north to Su zhan Road Ping jiang District of Suzhou City, East of Fangcao Road, and south of the project is the Square of Suzhou train station, north is the hehe road,.and it is away from the planned Metro Line 4 recently about 130m from the West, the planned Metro Line 2 recently about 120 m , transportation is convenient, the geographical environment is superior. 

The scope of the foundation pit excavation is 25,200 square meters, and the excavation depth is 11.9m, east, west, south side is on the open space, north is on a smaller land.It is manifestly that we cannot grading all over the scope of land.It is too expensive to just use the Filling Pile,so,considering about the budget,we can just grading partsof it,and use nondisplacement piles as retaining structure, anchor rod bracing and inclined steel pipe bracing concrete bracing as bracing structures.Around the foundation pit, we use deep churning piles as detaining water pile construct enclosed cut off trench. With the purpose of dewatering, we use sump and well point .

    Key words:  Bracing structure; Reinforced concrete structures; Pipe bracing; Nondisplacement pile

目 录第一章  绪论 1

1.1选题的目的及意义 1

1.1.1 选题的目的 1

1.1.2 选题的意义 1

1.2国内外研究现状及存在的问题 1

1.2.1国内现状 1

1.2.2国外现状 2

1.2.3存在的问题 2

第二章 围护设计说明 3

2.1 工程概况 3

2.1.1场地，建筑物--状况 3

2.1.2周边环境 4

2.1.3设计依据 4

2.1.4场地现状和工程地质条件 5

2.1.5水文地质条件 6

2.2围护结构选择 7

第三章 围护体系计算说明 11

3.1基坑围护方案设计参数说明 11

3.1.1土层指标参数 11

3.1.2 地面荷载取值 12

3.2东西南侧土钉结构计算书 12

3.2.1土钉参数的确定 12

3.2.2土钉长度计算 13

3.2.3土钉抗拔力验算 17

3.2.4面层设计计算 19