Unit5Loadactionandpropagation(工程管理專業(yè)英語)課件

1、Unit Five Load Action and Propagation The Main Contents Loads are forces acting on a structure. A proper appreciation of the behavior of a structural system, is essential to its proper design, thus requiring a correct understanding of the mechanisms and methods of load propagation, such as tension,

2、compression, bending, shear, and torsion, for simple systems and an additional elementary knowledge of at least deflections for somewhat more complex systems. 第1頁，共16頁。Vocabularypropagation n. 傳遞，傳導，傳播partitioning wall 隔墻cladding wall 填充墻rectangular coordinate 直角坐標verbalize vt., vi. 用詞語表達deflect vt.

3、, vi. 撓曲，下垂statically indeterminate structure 超靜定結構static determinacy 靜定Unit Five Load Action and Propagation 第2頁，共16頁。Vocabularyappreciation n. 評價，鑒賞the law of equilibrium 平衡原理suspension bridge 懸索橋geometry n. 幾何形狀，幾何學buckling n. 彎曲，屈曲，翹曲bracing n. 斜桿，支撐drastically adv. 徹底地，激烈地resultant adj. 合成的，總的U

4、nit Five Load Action and Propagation 第3頁，共16頁。English-Chinese translation平衡原理 the law of equilibrium 基礎沉降 foundation settlement風洞試驗 wind tunnel test人口的平均密度 the average population density 地震和海嘯 earthquake and tsunamiline of action and the sense of the force力的作用線和力的指向load action and propagation mechan

5、ism荷載作用和傳遞機理rectangular coordinate axes 直角坐標軸dead loads and live loads 恒載和活載strength and stability criteria 強度和穩(wěn)定性準則Unit Five Load Action and Propagation 第4頁，共16頁。Dead loads may be defined as the static forces that are the weights of load-column, beam, floor, partitioning wall, cladding wall, etc. 恒

6、載被定義為柱、梁、樓板、隔墻、填充墻等自重的靜力。 本句為被動語態(tài)，主語為Dead loads，謂語為may be defined as。that are the weights of cladding wall為修飾the static forces的定語從句。 Key StructuresUnit Five Load Action and Propagation 第5頁，共16頁。All these loads, whatever from inside or outside the building, depend largely on the location of the build

7、ing, have to be taken by the structural system from all points and manners of application and transferred to the foundations. 所有這些荷載，無論是來自建筑物內部還是外部，在很大程度上取決于建筑物的位置，這些荷載由結構體系從各個點以各種作用方式傳遞到基礎。 主語為All these loads，謂語為depend on，have to be taken by和(have to be) transferred to。whatever from inside or outsi

8、de the building為插入語，為“無論是來自建筑物內部還是外部”的意思。 Key StructuresUnit Five Load Action and Propagation 第6頁，共16頁。In statics, the total moments, shears, and other stresses caused by a group of loads are equal to the sum of the separate loads if the materials are in the elastic stage. 在靜力學中，如果材料處于彈性階段, 則所有的彎矩、剪

9、力以及其它由一組荷載引起的應力與這些荷載單獨作用產生的應力之和相等。 主語為the total moments, shears, and other stresses，謂語為are equal to。caused為過去分詞作后置定語，修飾other stresses。if the materials are in the elastic stage為條件狀語從句。 Key StructuresUnit Five Load Action and Propagation 第7頁，共16頁。Comprehension ExercisesWhat is load? What are the types

10、 of loads according to the direction of the force? Give some examples respectively. Loads are forces acting on a structure. Their way through the structural system to the foundation is either vertical, such as dead load, live load, snow; or horizontal, such as earthquake, wind. Unit Five Load Action

11、 and Propagation 第8頁，共16頁。Comprehension Exercises2. What are the mechanisms and methods of load propagation for simple systems and for somewhat more complex systems？ The mechanisms and methods of load propagation are tension, compression, bending, shear, and torsion for simple systems.An additional

12、elementary knowledge of at least deflections for somewhat more complex systems. Unit Five Load Action and Propagation 第9頁，共16頁。Comprehension Exercises3. Which are static loads and which are dynamic loads? Illustrate respectively. Static loads： the weights of load-column, beam, floor, partitioning wa

13、ll, cladding wall, etc and windloads. Dynamic loads： the live loads of people, library bookshelves, furniture, hospital beds, industrial equipment, etc , snow loads and earthquake loads.Unit Five Load Action and Propagation 第10頁，共16頁。Comprehension Exercises4. In statics, what conditions must the str

14、ucture satisfy when it is in equilibrium? (1) The sum of the horizontal forces must equal zero. (2) The sum of the vertical forces must equal zero. (3) The sum of the moments about three rectangular coordinate axes must equal zero. Unit Five Load Action and Propagation 第11頁，共16頁。Reading MaterialUnit

15、 Five Load Action and Propagation cap 柱頭，承臺jacked 插座，千斤頂；抬起，增加，提高 magnitude 巨大，廣大，重大，大小，強度end bearing piles 端承樁stratum 層，地層，階層porosity 多孔，空隙Compressibility 壓縮性compaction piles 密實樁，壓實樁第12頁，共16頁。Reading MaterialUnit Five Load Action and Propagation bearing stratum 持力層，承重層bored piles 填充樁，螺旋鉆孔樁tension p

16、iles 受拉樁，拉力樁pressure creosoting 雜酚油加壓浸漬，壓注油浸防腐法Prefabricated 預知的cathodic protection 陰極保護，陰極防蝕法，陰極防蝕第13頁，共16頁。Analysing the sentencesUnit Five Load Action and Propagation Piles are long and slender members which transfer the load to deeper soil or rock of high bearing capacity avoiding shallow soil of low bearing capacity. 第14頁，共16頁。Analysing the sentences Unit Five Load Action and Propagation If the results of site investigation show that the shallow soil is unstable and weak or if the magnitude of the estimated settlement is not