建筑構(gòu)造基礎(chǔ)51885.ppt

1、第二章 基礎(chǔ) Unit Foundation,The foundation is located underground and forms the base of the building. The purpose of the foundation is to carry the load of the structure and spread it over a greater area, evenly and without undue settlement, to the ground beneath. The size and type of foundation depends

2、on the nature of the ground and the load carried by it.,第二章 基礎(chǔ),第一節(jié) 地基與基礎(chǔ)的基本概念 地基：支撐建筑物的土層 一、天然地基和人工地基 Natural Ground and Artificial Ground （一）天然地基 Natural Ground： 天然的能夠受力的土層。 種類,巖石 rock 碎石土 crushed stone soil 砂土 sandy soil 粘性土 clay 人工填土 earth-fill,（二）人工地基 Artificial Ground When the capacity of the s

3、oil to support loads isnt enough, artificial ground has to be used. 壓實(shí)法 compaction method 換土法 replacement method 樁基 pile foundation compactor:壓實(shí)機(jī),replacement method To improve the bearing capacity in varying ground conditions, soft spots are usually filled with consolidated hardcore or a weak concre

4、te, before the foundation is laid. Consolidate: 加強(qiáng)、鞏固 Hardcore:碎磚石 weak concrete：低標(biāo)號(hào)混凝土,pile foundation When a foundation is laid in poor soil, it is necessary to excavate to a greater depth than normal to reach a solid base. If a good base cannot be found at a reasonable depth, then a so-called dee

5、p foundation must be provided. This usually comprises a series of driven or cast-in-situ reinforced concrete piles. Excavate: 開鑿、挖掘,二、基礎(chǔ)的埋置深度 The Depth of a Foundation,1、淺基礎(chǔ) shallow foundation 500MM埋置深度4米， 2、深基礎(chǔ) deep foundation 埋置深度4米,適宜的深度？ Which elements decide the depth of a foundation? 地基情況 the

6、nature of the ground 地下水位的影響 groundwater level 冰凍線 frost line 其它 other elements?,三、基礎(chǔ)的類型 Types of the Foundations,（一）按基礎(chǔ)的形式分類dividing foundations by forms 1、條形基礎(chǔ) Strip Foundation 特點(diǎn)：連續(xù)的帶形，也可叫帶形基礎(chǔ)。 適用情況：當(dāng)?shù)鼗鶙l件好，基礎(chǔ)埋置深度較淺時(shí)。,材料：磚、石、混凝土、鋼筋混凝土,適用什么樣的上部結(jié)構(gòu)？,2、獨(dú)立式基礎(chǔ) Individual Footing 特點(diǎn)： 呈獨(dú)立的塊狀，形式有杯形、階梯形、錐形。

7、 Socket foundation 杯形基礎(chǔ) Benched foundation 階梯形基礎(chǔ) Cone foundation 錐形基礎(chǔ),A socket foundation is the footing with socket for a prefabricated column.,適用情況：當(dāng)上部結(jié)構(gòu)為框架時(shí)。 frame structure:框架結(jié)構(gòu) 材料：鋼筋混凝土。,3、聯(lián)合基礎(chǔ)Combined Footing 1）柱下條形基礎(chǔ) Strip Foundation under Columns：將柱下獨(dú)立基礎(chǔ)連接起來，形成連續(xù)的條形基礎(chǔ)。,Isolated columns are n

8、ormally 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）柱下十字交叉基礎(chǔ) Crossed Strip Foundation under Columns： 將條形基礎(chǔ)做成

9、網(wǎng)格狀，提高了基礎(chǔ)的穩(wěn)定性，使荷載分布更為均勻。,3）梁板式基礎(chǔ) Beam and Slab Foundation： 有肋筏板基礎(chǔ)。,4）板式基礎(chǔ) Mat Foundation： 筏板基礎(chǔ) 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 consi

10、sts of a reinforced concrete slab, on which the walls are built.,5）箱形基礎(chǔ) Box Foundation(Cellular Mat) 鋼筋混凝土板與地下室墻組合的結(jié)構(gòu)。 basement: 地下室 basement wall: 地下室墻,6）樁基Pile Foundation：樁、樁帽和系梁的系統(tǒng)，將建筑物荷載向下傳遞到適當(dāng)?shù)某至印?bearing stratum: 持力層 pile cap: 樁帽、樁臺(tái) tie beam: 系梁,機(jī)械成孔灌注樁、人工挖孔樁、混凝土預(yù)制樁、管樁、高壓旋噴樁、擺噴樁,鉆孔樁,攪拌樁等,（二）按

11、材料分類：剛性基礎(chǔ)、柔性基礎(chǔ) dividing foundations by materials 1、剛性基礎(chǔ) Rigid Foundation： 材料：磚、石、混凝土 抗壓但抗剪和抗彎能力差。 compressive resistance: 抗壓 shearing resistance:抗剪 bending resistance :抗彎 剛性角：rigid angle 拉力: tensile force 壓力: pressure 剪力: shear,2、柔性基礎(chǔ) Flexible Foundation： 抗壓和抗彎剪能力都很好，不受剛性角的限制。 材料：鋼筋混凝土,第二節(jié) 常用剛性基礎(chǔ)構(gòu)造P

12、art The Construction of Common Rigid Foundation,一、磚基礎(chǔ) Brick Foundation 1、強(qiáng)度 strength：磚的強(qiáng)度不得低于MU10 墊層 bed course： 水泥砂漿 三七灰土 三合土,二、石基礎(chǔ) Stone Foundation 毛石基礎(chǔ) Rubble Foundation 尺寸：寬度和厚度150MM，長(zhǎng)度為寬度的 52。5倍。 強(qiáng)度：M5 CONSTRUCION：,料石基礎(chǔ) Squared Stone Foundation： 經(jīng)過加工后的石料。 基礎(chǔ)的寬度除了按計(jì)算要求外，還應(yīng)符合料石的規(guī)格尺寸。,三、混凝土及毛石混凝土基礎(chǔ)Concrete and Rubble Concrete Foundation,滿足剛性角的要求 什么情況下用毛石混凝土基礎(chǔ)呢？ 當(dāng)混凝土基礎(chǔ)體積過大時(shí)，可以填充一些毛石。,第三節(jié) 基礎(chǔ)沉降縫構(gòu)造Part The construction of Foundation Set