【摘要】本设计是南京地铁2号线车站基坑围护结构设计，基坑较深且存在承压水层。重点包括了四个大的方面：支护方案的挑选、围护结构设计与计算、基坑的降排水和施工组织规划。根据基坑的工程概况及其特点，在考虑基坑的安全性和经济性的前提下选择了钻孔咬合桩作为挡土结构兼作止水帷幕。采用郎肯理论计算水土压力，采用等值梁法计算了墙体内力、弯矩和嵌固深度。用轻型井点降水法降水。由于基坑较深、较大，而且有较丰富的承压水，所以利用了钻孔咬合桩作为本基坑即南京地铁2号线车站基坑的支护类型。48122

【毕业论文关键词】水土压力；钻孔咬合桩；承压水降水；稳定性验算；内力计算

Foundation pit design of Nanjing Metro Line 2

Abstract: This design is the foundation pit retaining structure design of Nanjing Metro Line 2. The focus includes four major aspects: selection of retaining scheme, design and calculation of retaining structure, reduction and drainage of foundation pit and construction organization plan. According to the general situation of the project of the foundation pit and its features, in consideration of the safety of the foundation pit and economic premise of choose of bored occluding pile as a retaining structure soil doubles as a water stop curtain. The internal force, bending moment and embedded depth of the wall are calculated by using the equivalent beam method in the calculation of the soil and water pressure. Light well point precipitation method. Because of the deep foundation pit, larger, but also has a rich bearing water, so the use of bored pile as the foundation pit that is, Nanjing Metro Line 2 station foundation pit support type.

KeyWords: Water and soil pressure; bored pile; confined water dewatering; stability checking calculation; internal force calculation

 目录

1 工程概况 1

1.1 工程概况 1

1.2 水文地质工程条件 1

1.2.1 工程地质层分布与特征描述 1

1.2.2 水文地质条件 2

2 基坑围护方案选用与比较 3

2.1 基坑支护的类型及其特点和适用范围 3

2.1.1 钻孔灌注桩+止水帷幕法 3

2.1.2 土钉墙 3

2.1.3 排桩支护 3

2.1.4 槽钢钢板桩 4

2.1.5 型钢水泥土搅拌桩墙（SMW工法） 4

2.1.6 地下连续墙 4

2.2 基坑特点及方案比选 5

2.2.1 基坑特点 5

2.2.2 基坑安全等级 5

2.2.3 基坑支护设计参数 5

2.2.4 方案比选 5