道桥专业英语PPT精选文档

1、1,道路与桥梁工程专业英语,2,第一讲 绪论,一.专业英语是什么（what）？ 二. 为什么要学习专业英语（why）？ 三.怎么样学习专业英语（how）？,3,第一讲 绪论,一.专业英语是什么（what）？ 1、概念 专业英语：English for special purpose,简称ESP。 专业：针对相应专业知识，专业术语，专业常识，所以应以专业知识理论为基础。 英语：国际语言，便于交流，包括学术交流、文献参阅、文章撰写等。,4,5,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.1 语言特点 语言简练，表达明确，不重润饰 The shoulder width of urb

2、an and rural freeways is dependent upon the number of lanes of the facility. The right side shoulder for both urban and rural freeways shall be 10 feet. This width allows for emergency parking of vehicles on the right hand shoulder. The left side shoulder is dependent on the number of freeway lanes.

3、,6,第一讲,一.专业英语是什么（what）？ 2、特点 2.1 语言特点 逻辑严谨，概念清晰，关系分明 Asphalt is called a bituminous material because it contains bitumen, a hydrocarbon material soluble in carbon disulfate(一个易溶于二硫化碳烃类物质). The tar(焦油） obtained from the destructive distillation of soft coal also contains bitumen. Both petroleum aspha

4、lt and coal tar are referred to as bituminous materials.,7,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 非人称的语气和客观的态度，常用It结构 It is important, though, to design freeways, urban and rural, that provide a consistent roadway for drivers.,8,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 多用被动结构 A freeway may be defined as

5、 a divided highway facility having two or more lanes for the exclusive use of traffic in each direction and full control of access and egress. 高速公路可定义为每个方向具有两条或两条以上汽车专用车道，并且进出口完全控制的被分隔的公路设施。,9,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 多用动词非谓语结构 In general, the design speed of freeways should be similar

6、to the desired running speed during off peak hours, keeping in mind a reasonable and prudent speed.,10,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 祈使语句和公式化表达方式 在理论分析和公式推导中常采用Assume that，Suppose that，Let等祈使语气表达方式。 So, next let us look at how to use SYNCHRO to do signal timing and simulation work. 因此，接下来让我们

7、看看如何使用SYNCHRO来进行信号配时和交通仿真工作。,11,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 条件句较多 条件句多用于条件论述、理论分析和公式推导中，最常用的是If语句。 The huge investment in the highway infrastructure will be erased quickly if proper maintenance and rehabilitation procedures are enforced and funded. 若合理的养护和修护计划得以资助并实施，就可迅速取消用于公路基础建设的巨大投资。,1

8、2,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 多用长句 One of the effects of oxidation is that the binder loses flexibility and therefore becomes harder and more susceptible to the abrasive effects of traffic; an oxidized binder is thus likely to wear away in preference to particles of coarse aggregate set in

9、 the surface, allowing the chippings to protrude from the surface and improve the skidding resistance.,13,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 省略句较多 为了简洁，有时省略掉句子中的一些成分，如状语从句中的主语和谓语、定语从句中的关联词which或that, 从句中的助动词等。 If not well managed, the procedure for construction may be more expensive. 如果管理不善，这一施工方

10、法还可能更费钱。 常见的省略（状语从句中的主语和谓语的）句型有： As already discussed 前已讨论 If possible 如果可能的话 As described above 如前所述 If so 倘若如此 As explained before 前已解释 When necessary 必要时 As indicated in Fig.1 如图1所示 When needed 需要时 As previously mentioned 前已述及 Where feasible 在实际可行的场合 If necessary 如果必要的话 Where possible 在可能的情况下,14,

11、第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.2 语法特点 大量使用名词化结构 名词化特点主要是指在专业文献中广泛使用能表示动作和状态的名词，或是起名词作用的非限定动词。 In the initial stages of road design it is usual for several alternative route proposals to be considered but only outline details of road center lines and estimates of speeds and flows are available. 在道路设计

12、的初始阶段，通常有多种备选的路线方案需要考虑，但这时只有道路中线的概要数据和车速及流量的预测值。,15,第一讲 绪论,一.专业英语是什么（what）？ 2、特点 2.3 词汇特点 专业词汇 2.4 结构特点 每一自然段落中，总有一个语句概括出该段落的重点。这个语句或在段落之首，或在段落之尾，较少出现在段落中间。若干个自然段会形成一个逻辑（或结构）段落，用以从不同角度来解说某一层面的核心内容。全篇则由若干个逻辑段落组成，从不同层面来阐述文章标题所标明的中心思想。实际上，专业文献中通常采用的标题、子标题、编号等形式，就是对文章结构的逻辑划分,16,Highway engineering is an

13、 engineering discipline branching from civil engineering which involves the design, construction and maintenance of highway systems. Highway engineering became prominent towards the latter half of the 20th Century after World War 2. Standards of highway engineering are continuously being improved. H

14、ighway engineers must take into account future traffic flows, design of highway intersections/interchanges, geometric alignment and design, highway pavement materials and design, structural design of pavement thickness, and pavement maintenance. Most developed nations have extensive highway networks

15、.,17,The most appropriate location, alignment, and shape of a highway are selected during the design stage. Highway design involves the consideration of three major factors (human, vehicular, and roadway) and how these factors interact to provide a safe highway. Human factors include reaction time f

16、or braking and steering, visual acuity for traffic signs and signals, and car-following behavior.,18,Vehicle considerations include vehicle size and dynamics that are essential for determining lane width and maximum slopes, and for the selection of design vehicles. Highway engineers design road geom

17、etry to ensure stability of vehicles when negotiating curves and grades and to provide adequate sight distances for undertaking passing maneuvers along curves on two-lane, two-way roads. vehicle dynamics 汽车的动力 lane width车道宽度 maximum slopes 最大纵坡度 design vehicles设计车辆 design vehicles视距 two-lane, two-wa

18、y roads双向双车道道路,19,Geometric Design Highway and transportation engineers must meet many safety, service, and performance standards when designing highways for certain site topography. Highway geometric design primarily refers to the visible elements of the highways. Highway engineers who design the g

19、eometry of highways must also consider environmental and social effects of the design on the surrounding infrastructure（基础设施）.,20,Geometric Design There are certain considerations that must be properly addressed in the design process to successfully fit a highway to a sites topography and maintain i

20、ts safety. Some of these design considerations include Design speed, Design traffic volume, Number of lanes, Level of Service (LOS), Sight Distance, super-elevation, and grades, Cross section, Lane width, Horizontal and vertical clearance. The operational performance of a highway can be seen through

21、 drivers reactions to the design considerations and their interaction. Level of Service (LOS)服务水平 Sight Distance-视距 super-elevation-超高 Grade-纵坡度 cross section-横断面 lane width-车道宽,21,Materials The materials used for roadway construction have progressed with time, dating back to the early days of the R

22、oman Empire. Advancements in methods with which these materials are characterized and applied to pavement structural design has accompanied this advancement in materials. There are two major types of pavement surfaces -Portland cement concrete (PCC) and hot-mix asphalt (HMA). Portland cement concret

23、e (PCC)-普通硅酸盐水泥 hot-mix asphalt (HMA)-热拌沥青混合料,22,Flexible Pavement Design A flexible, or asphalt, pavement typically consists of three or four layers. For a four layer flexible pavement, there is a surface course, base course, and subbase course constructed over a compacted, natural soil subgrade. W

24、hen building a three layer flexible pavement, the subbase layer is not used and the base course is placed directly on the natural subgrade. Flexible Pavement柔性路面 surface course-面层 Layers-结构层 base course -基层 subbase course-底基层 soil subgrade-土基,23,A flexible pavements surface layer is constructed of h

25、ot-mix asphalt (HMA). Unstabilized aggregates are typically used for the base course; however, the base course could also be stabilized with asphalt, Portland cement, or another stabilizing agent. The subbase is generally constructed from local aggregate material, while the top of the subgrade is of

26、ten stabilized with cement or lime.,24,With a flexible pavement, the highest stress occurs at the surface and the stress decreases as the depth of the pavement increases. Therefore, the highest quality material needs to be used for the surface, while lower quality materials can be used as the depth

27、of the pavement increases. Stress-应力；,25,The term flexible is used because of the asphalts ability to bend and deform slightly, then return to its original position as each traffic load is applied and removed. It is possible for these small deformations to become permanent, which can lead to rutting

28、 in the wheel path over an extended time. The service life of a flexible pavement is typically designed in the range of 15 to 20 years. traffic load车辆荷载 Rutting车辙 service life使用寿命,26,Rigid Pavement,Rigid pavements are generally used in constructing airports and major highways, such as those in the interstate highway system. Like flexible pavements, rigid highway pavements are designed as all-weather, long-las