Unit5Loadactionandpropagation(工程管理专业英语)课件

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页，共16页。Vocabularypropagation n. 传递，传导，传播partitioning wall 隔墙cladding wall 填充墙rectangular coordinate 直角坐标verbalize vt., vi. 用词语表达deflect vt.

3、, vi. 挠曲，下垂statically indeterminate structure 超静定结构static determinacy 静定Unit Five Load Action and Propagation 第2页，共16页。Vocabularyappreciation n. 评价，鉴赏the law of equilibrium 平衡原理suspension bridge 悬索桥geometry n. 几何形状，几何学buckling n. 弯曲，屈曲，翘曲bracing n. 斜杆，支撑drastically adv. 彻底地，激烈地resultant adj. 合成的，总的U

4、nit Five Load Action and Propagation 第3页，共16页。English-Chinese translation平衡原理 the law of equilibrium 基础沉降 foundation settlement风洞试验 wind tunnel test人口的平均密度 the average population density 地震和海啸 earthquake and tsunamiline of action and the sense of the force力的作用线和力的指向load action and propagation mechan

5、ism荷载作用和传递机理rectangular coordinate axes 直角坐标轴dead loads and live loads 恒载和活载strength and stability criteria 强度和稳定性准则Unit Five Load Action and Propagation 第4页，共16页。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、载被定义为柱、梁、楼板、隔墙、填充墙等自重的静力。 本句为被动语态，主语为Dead loads，谓语为may be defined as。that are the weights of cladding wall为修饰the static forces的定语从句。 Key StructuresUnit Five Load Action and Propagation 第5页，共16页。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. 所有这些荷载，无论是来自建筑物内部还是外部，在很大程度上取决于建筑物的位置，这些荷载由结构体系从各个点以各种作用方式传递到基础。 主语为All these loads，谓语为depend on，have to be taken by和(have to be) transferred to。whatever from inside or outsi

8、de the building为插入语，为“无论是来自建筑物内部还是外部”的意思。 Key StructuresUnit Five Load Action and Propagation 第6页，共16页。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. 在静力学中，如果材料处于弹性阶段, 则所有的弯矩、剪

9、力以及其它由一组荷载引起的应力与这些荷载单独作用产生的应力之和相等。 主语为the total moments, shears, and other stresses，谓语为are equal to。caused为过去分词作后置定语，修饰other stresses。if the materials are in the elastic stage为条件状语从句。 Key StructuresUnit Five Load Action and Propagation 第7页，共16页。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页，共16页。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页，共16页。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页，共16页。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页，共16页。Reading MaterialUnit

15、 Five Load Action and Propagation cap 柱头，承台jacked 插座，千斤顶；抬起，增加，提高 magnitude 巨大，广大，重大，大小，强度end bearing piles 端承桩stratum 层，地层，阶层porosity 多孔，空隙Compressibility 压缩性compaction piles 密实桩，压实桩第12页，共16页。Reading MaterialUnit Five Load Action and Propagation bearing stratum 持力层，承重层bored piles 填充桩，螺旋钻孔桩tension p

16、iles 受拉桩，拉力桩pressure creosoting 杂酚油加压浸渍，压注油浸防腐法Prefabricated 预知的cathodic protection 阴极保护，阴极防蚀法，阴极防蚀第13页，共16页。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页，共16页。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