文档介绍：第二章 基础
第一节 地基与基础的基本概念
地基：支撑建筑物的土层
一、天然地基和人工地基 Natural Ground and Artificial Ground
（一）天然地基 Natural Groud concrete piles.
Excavate: 开凿、挖掘
二、基础的埋置深度 The Depth of a Foundation
1、浅基础 shallow foundation
500MM≤埋置深度≤4米，
2、深基础 deep foundation
埋置深度≥4米
适宜的深度？
Which elements decide the depth of a foundation?
地基情况 the nature of the ground
地下水位的影响 groundwater level
冰冻线 frost line
其它 other elements???
三、基础的类型 Types of the Foundations
（一）按基础的形式分类dividing foundations by forms
1、条形基础
Strip Foundation
特点：连续的带形，也可叫带形基础。
适用情况：当地基条件好，基础埋置深度较浅时。。。
材料：砖、石、混凝土、钢筋混凝土
适用什么样的上部结构？
2、独立式基础 Individual Footing
特点：
呈独立的块状，形式有杯形、阶梯形、锥形。
Socket foundation 杯形基础
Benched foundation 阶梯形基础
Cone foundation 锥形基础
A socket foundation is the footing with socket for a prefabricated column.
适用情况：当上部结构为框架时。。。
frame structure:框架结构
材料：钢筋混凝土。。。
3、联合基础Combined Footing
1）柱下条形基础
Strip Foundation under Columns：将柱下独立基础连接起来，形成连续的条形基础。
Isolated columns are normally supported on square concrete foundation bases. Where such columns are spaced at close intervals, it is often more practical to provide a continuous concrete strip foundation to carry a complete row, as is done for load bearing walls.
2）柱下十字交叉基础
Crossed Strip Foundation under Columns：
将条形基础做成网格状，提高了基础的稳定性，使荷载分布更为均匀。
3）梁板式基础
Beam and Slab Foundation：
有肋筏板基础。。。
4）板式基础 Mat Foundation：
筏板基础 Raft
Where the bearing capacity is particularly poor or the quality of the soil varies considerably, a raft foundation is often recommended to support normal buildings. This type of foundation simply consists of a reinforced concrete slab, on which the walls are built.
5）箱形基础 Box Foundation(Cellular Mat)
钢筋混凝土板与地下室墙组合的结构。。。
basement: 地下室
basement wall: 地下室墙
6）桩基Pile Foundation：桩、桩帽和系梁的系统，将建筑物荷载向下传递到适当的持力层。。。
bearing stratum: 持力层
pile cap: 桩帽、桩台
tie beam: 系梁
机械成孔灌