Lesson 7 Transportation Systems交通运
输系统
Transportation system in a developed nation consists of a network of modes that have evolved over many years. The system consists of vehicles, guideways, terminal facilities and control systems: these operate according to established procedures and schedules in the air,on land, and on water. The system also requires interaction with the user, the operator and the environment. The systems that are in place reflect the multitude of decisions made by shippers, carriers, government, individual travelers, and affected nonusers concerning the investment in or the use of transportation. The transportation system that has evolved has produced a variety of modes that complement each other.
在发达国家，交通运输系统由网状结构组成的模式已经发展了好多年。这个系统由交通工具、轨道、站场设施和控制系统组成。这些依照空中、陆上和水上已制定的程序和计划运转。这个系统也需要和用户、司机和环境互动。现在的运输体系可以反映出与投资和使用有关的多方决定，包括运输业主、承运商、政府、每个出行者以及受影响的非使用者等。逐步发展的交通运输系统形成了各种互补模式。
The U. S. transportation system today is a highly developed, complex network of modes and facilities that furnishes shippers and travelers with a wide range of choices in terms of services provided. Each mode offers a unique set of service characteristics in terms of travel time, frequency, comfort, reliability, convenience and safety. The term level of service is used to describe the relative values of these attributes. The traveler or shipper must compare the level of service offered with the cost in order to make tradeoffs and mode selection. Furthermore, a shipper or traveler can decide to use a public carrier or to use private (or personal) transportation. For example, a manufacturer can ship goods through a trucking firm or with company trucks, a homeowner who has been relocated can hire a household moving company or rent a truck, and a commuter can elect to ride the bus to work or drive a car. Each of these decisions involves a complex set of factors that require
tradeoffs between cost and service.
当今美国的交通运输系统是一个高度发达，复杂的运输方式和设施构成的网络，他们为运输业主和出行者提供服务，并有很大的选择余地。每种模式按照行程时间、频率、舒适度、可靠性、方便性和安全性都具有一种独特的服务特性。服务水平被用来描述相对价值。旅客或运输业主对比同等费用下的服务水平来权衡和选择运输方式。此外，运输业主或旅客可以决定使用公共的或是私人运输方式。例如，厂商可以通过货运公司或者自己公司的卡车运货，要搬家的屋主可以选择雇佣搬家公司或者租赁卡车，通勤者可以选择乘公交或者开车去上班。每种决定都涉及一系列需要在费用和服务间权衡的复杂因素。
The principal modes of intercity freight transportation are highways, railroads, water, air and pipelines. Traffic carried by each mode, expressed as ton-miles or passenger-miles, has varied considerably in the past 70 years. The most current information regarding modal market share is available from the Bureau of Transportation Statistics (BST) website. Changes in ton-miles carried from 1960 through 2005 are illustrated in Fig. 7.1.
主要的城际货运方式有铁路、公路、水运、空运和管道运输。在过去的70年里，表现为货运和客运的每一种运输方式发生了很大的改变。关于市场占有率的最新消息可以从BST网站获取。从1960年至2005年货运方式变化如图7.1所示。
The distribution of passenger transportation is much different from that for freight: one mode-the automobile-accounts for the highest number of all domestic intercity passenger-miles traveled in the United States. The remaining modes-air, bus and rail-share a market representing about one quarter of the total, with air being the dominant mode and intercity bus, private air carriers and rail representing 1 percent or less of the total.
客运的分布与货运有很大不同：在美国，私家车这种方式在所有的家庭城际客运旅行中数量最多。剩下的方式（航空、公共汽车和铁路）占总数的四分之一，其中航空占优势，而城际公共汽车、私家人飞机和铁路占总量的百分之一或更少。
Each mode has inherent advantages of cost, travel time, convenience
and flexibility that make it “right for the job” under a certain set of circumstances. The automobile is considered to be a reliable, comfortable, flexible and ubiquitous form of personal transportation for many people. However when distances are great and time is at a premium, air transportation will be selected, supplemented by the auto for local travel. If cost is important and time is not at a premium, or if an auto is not available, then intercity bus or rail may be used.
在费用，旅行时间，方便性和灵活性等方面，每种方式都有自身的优势，从而使得它在特定情形下成为最佳选择。对很多人来说，汽车是一种可靠、舒适、灵活且普遍存在的私人运输方式。然而，当距离很远或者时间很宝贵时，人们将选择航空运输并在当地运输中补以汽车运输。如果费用很重要而时间并不紧，或者不能使用汽车时，可以使用城际巴士或火车。
Selecting a mode to haul freight follows a similar approach. Trucks have the advantages of flexibility and the ability to provide
door-to-door service. They can carry a variety of parcel sizes and usually can pick up and deliver to meet the customer?s schedule. Waterways can ship heavy commodities at low cost, but only at slow speeds and between points on a river or canal. Railroads can haul an immense variety of commodities between any two points, but usually require truck transportation to deliver the goods to freight terminal or to their final destination. In each instance,a shipper must decide whether the cost and time advantages are such that the goods should he shipped by truck alone or by a combination of truck, waterway and rail.
选择货运方式也可以遵循相似方法。卡车的优势在于灵活和提供门到门服务。卡车可以运送多种尺寸货物并可以按照客户时间表上门收取或交付货物。水运可以低价运送很重的货物，但是速度很低，并且只能在河流或运河的两点间运送。铁路可以在任意两地间运送大量货物，但往往需要卡车再将货物转运到终点或目的地。每种方式，托运商都要权衡花费和时间来决定只用卡车或者通过卡车、水运和火车联运。
Many industries have been trying to reduce their parts and supplies inventories,preferring to transport them from the factory when needed rather than stockpiling them in a warehouse. This practice has meant
shifting transportation modes from rail to truck. Rail shipments are usually made once or twice a week in carload lots, whereas truck deliveries can be made in smaller amounts and on adaily basis, depending on demand. In this instance, lower rail-freight rates do not complete with truck flexibility, since the overall result of selecting trucking is a cost reduction for the industry. There is a trend towardintermodalism which has combined the capabilities of both modes.
许多公司都尝试减少零部件和原材料库存，相比把货物存积在仓库，商家更喜欢需要的时候直接从工厂运输。这种做法意味着运输方式从火车到卡车的转变。火车运输通常是以每周一到两次的频率整车运输，而卡车可以按需求每天少量的运送。这种情况下，较低的火车运输费用都难以和汽车的灵活性相竞争，因为厂商选择卡车的全部原因是开支的减少。有一种趋势指向将各种方式结合起来的联运制。
The nation?stransportation system can be considered to be in a state of equilibrium at any given point in time as a result of market forces, government actions and transportation technology.As these change over time, the transportation system also will be modified. During recent decades, changes in gasoline prices, regulation by government, and new technology have affected the relative importance of each mode. The passenger or shipper thinks of each mode in terms of the level of service provided. Each mode offers a unique set of service characteristics at a given price: travel time, frequency, comfort, convenience, reliability and safety. The traveler or shipper selects the mode based on how these attributes are valued.
国家的运输系统可以看作一种在市场压力、政府管控、运输新技
术下的平衡。随着时间变化，运输系统也会改变。近几十年，油价的改变、政府的管控和新的技术已经对运输业造成了很大影响。旅客或托运商按照服务水平考虑每一种方式。每种方式在给定的价格下提供一种独特的服务特点：行程时间、频率、舒适度、方便性、可靠性和安全性。旅客和托运商按照这些属性的价值选择运输方式。
A wide range of organizations and agencies provide the resources to plan, design, build, operate and maintain the nation?s transportation
system. These include private companies that furnish transportation; regulatory agencies that monitor the safety and service quality provided; federal, state, local agencies that provide funds to build roads and airports and carry out legislation dealing with transportation at a national level; trade associations that represent the interests of a particular group of transportation providers or suppliers; professional organizations and transportation user groups.
许多组织和代理机构提供计划、设计、建设、操作和维持国家交通运输系统的资源。这些组织和机构包括：运输业私人公司、兼管安全和服务质量的管理机构、提供资金修建道路和机场并为交通制定全国性法规的联邦、州以及地方公路局；代表某一特殊运输群体利益的行业协会；专业技术组织以及运输使用者群体。
Lesson 8Highway Location公路定线
The basic principle for locating highways is that roadway elements such as curvature and grade must blend with each other to produce a system that provides for the easy flow of traffic at the design capacity, while meeting design criteria and safety standards.The highway should also cause a minimal disruption to historic and archeological sites and to other land-use activities.Environmental impact studies are therefore required in most cases before a highway location is finally agreed upon.
定线的基本原则是车行道要素如弯道和坡度必须互相组合，在满足设计规范和安全标准的要求的同时，提供满足设计通行能力并且平稳的交通流体系。公路应尽可能小的影响历史古迹及其他设施。绝大多数情况下，当公路路线位置最终确定前都要求进行环境影响评估。
The highway location process involves four phases:
? Office study of existing information
?Reconnaissance survey
?Preliminary location survey
?Final location survey
公路定线包括四个阶段：
?对已有信息进行室内研究
?勘测设计
?初步定线
?最终定线
Office Study of Existing Information
The first phase in any highway location study is the examination of all available data of the in which the road is to be constructed. This phase is usually carried out in the office prior toany fieldor photogrammetric investigation. All the available data are collected and examined. These data can be obtained from existing engineering reports, map, aerial photographs and charts, which are usually available at one or more of the state's departments of transportation, agriculture, geology,hydrology and mining. The type and amount of data collected and examined depend on the type of highway being considered, but in general, data should be obtained on the following characteristics of the area:
已有信息室内研究
所有公路选线第一阶段是对公路建设地区所有信息进行研究。这一阶段通常先于任何现场或图片调查在室内进行。所有可得数据被收集并考察。这些数据可以从现有工程报告、地图、航拍图片和图表中获取，这些东西通常都可以从一个或多个政府运输、农业、地理、水利及矿产部门获取。所收集并考察的数据类型和数量取决于拟建道路等级，但总体来说数据都要有该地区以下特征：?Engineering, including topography, geology, climate and traffic volumes.
?S ocial and demographic, including land use and zoning patterns. ?Environmental, including types of wildlife;location of recreational, historic and archeologicalsites: the possible effects of air, noise and water pollution.
?Economic, including unit costs for construction and trend of agricultural, commercial and industrial activities.
?工程上，包括地形、地质、气候和交通量
?社会和人口，包括土地使用和区划特征
?环境方面，包括野生动物类型；娱乐场所，历史遗迹的位置；可能产生的空气噪声和水污染
?经济方面，包括单位建设花费，农业趋势，商业和工业活动Preliminary analysis of the data obtained will indicate whether any of
the specific sites should be excluded from further consideration because of one or more of the above characteristics. For example, if it is found that a site of historic and archeological importance is located within an area being considered for possible route location, it maybe immediately decided that any route that traverses that site should be excluded from further consideration. At the completion of this phase of the study the engineer will be able to select general areas through which the highway can traverse.
初步分析所获取的数据将得出是否有地方由于上述因素的一个或多个被剔除在进一步考虑之外。例如，如果发现一个重要的历史古迹和建筑位于路线可能通过的区域，则应立即确定通过那个区域的任何线路下一步将不被考虑。在这一阶段结束后，工程师将能选择公路所能穿过的大体区域。
Reconnaissance Survey
The object of this phase of the study is to identify several feasible routes, each within a band of a limited width of a few hundred feet. When rural roads are being considered, there is often very little or no information available on maps or photographs, and therefore aerial photography is widely used to obtain the required information. Feasible routes are identified by a stereoscopic examination of the aerial photographs, taking into consideration factors such as:
?T errain and soil conditions
?S erviceability of route to industrial and population areas
?C rossing of other transportation facilities, such as rivers, railroads and other highways
?D irectness of route
勘测设计
这一阶段的的目标是找出几条可行路线，每一条都在几百英尺有限宽度的带状区。当考虑郊外公路时，在照片或地图上通常很少或没有可用信息，因此航空摄影被广泛采用来获取所需信息。通过航拍照片生成的立体透视图来检查可行路线所考虑的因素包括：地貌及土质
对工业及居民区服务能力
与其他交通设施如水路、铁路及其他公路的交叉情况
路线的直接性
Control points between the two endpoints are determined for each feasible route. For example, a unique bridge site with no alternative may be taken as a primary control point. The feasible routes identified are then plotted on photographic base maps.
两端点间的控制点对每条可行路线起控制作用。例如，无可选择的唯一的桥位就可被当作基本控制点。找出这些可行路线并标注在航拍照片的底图上。
Preliminary Location Survey
During this phase of the study, the positions of the feasible routes are set as closely as possible by establishing all the control points and determining preliminary vertical and horizontal alignments for each. Preliminary alignments are used to evaluate the economic and environmental feasibility of the alternative routes.
初步定线
在这一步的研究中，通过建立控制点和初步确定平纵线型，尽可能精确地确定可行路线的位置。初步定线用于评价备选路线的经济和环境可行性。
Economic evaluation of each alternative route is carried out to determine the future effect of investing the resources necessary to construct the highway.
对每条备选路线经济评价的目的在于确定投入资源修建的道路在未来所能产生的影响。
The benefit-cost ratio method is used for this evaluation. Factors usually taken into consideration include road user costs, construction costs, maintenance costs, road user benefits and any disbenefits, which may include adverse impacts due to dislocation of families, businesses and so forth. The results obtained from the economic evaluation of the feasible route provide valuable information to the decision maker. For example, these results will provide information on the economic resources that will be gained or lost if a particular location is selected. This information is also used to aid the policy maker in determining whether the highway should be built, and if so, what type of highway it should be.
在这一评估中采用效益成本比的方法。通常所考虑的因素包括用户的花费，建设费用，养护费用，使用者受益和一些损失，这些损失包括居民拆迁、对商业和其他的不利影响。从经济苹果中获得的结果给决策者提供有价值的信息。例如，结果将提供特定位置确定后经济资源上的得失信息。这一信息也用来帮助政策制定者决定公路是否该修建，如果该修那又该修何种等级的道路。Construction of a highway at any location will have a significant impact on its surroundings. A highway is therefore an integral part of the local environment and must be considered as such. This environment includes plant, animal human communities and encompasses social, physical, natural and man-made variables. These variables are interrelated in a manner that maintains equilibrium and sustains the life style of the different communities. The construction of a highway at a given location may result in significant changes in one or more variables, which in turn may offset the equilibrium and result in significant adverse effects on the environment. This may lead to a reduction of the quality of the animals and/or human communities. It is therefore essential that the environmental impact of any alignment selected be fully evaluated.
在任何地方修建道路都会对当地环境产生重要影响。因此公路应当被看成是当地环境完整的一部分。这一环境包括植物、动物、人类群体，同时包括社会的、物理的、自然的和认为的变量。这些变量是以一种维持平衡并维持不同群体间生活方式的方法相互关联的。在给定的区域内公路的修建可能会导致一个或多个变量的剧烈变化，这些变化反过来会试图修复平衡并会对环境产生非常不利的影响。这可能会导致动物与/或人类数量的减少。因此对任何线路的选择全面考虑对环境的影响是很必要的。
Final Location Survey
The final location survey is the detailed layout of the selected route. The horizontal and vertical alignments are determined and the positions of structures and drainage channels are located. The method used is to set out the points of intersections (PI) of the straight portions of the highway and fit a suitable horizontal curve between these. This is usually a trial-and-error process until, in the designer's opinion, the
best alignment is obtained, taking both engineering and aesthetic factors into consideration. Splines and curve templates are available that can be used in this process. The spline is a flexible plastic guide that can be bent into different positions and is used to lay out different curvilinear alignments, from which the most suitable is selected. Curve templates transparencies giving circular curves, three-center compound curves and spiral curves of different radii and different standard scales. The spline is used first to obtain a hand-fitted smooth curve that fits in with the requirements of grade, cross-sections, curvature and drainage. The hand-fitted curve is then changed to a more defined curve by using the standard templates.
最终定线
最终定线是对选定的路线进行详细设计。在这一阶段确定平纵面线形和排水沟位置。传统方法是设定公路直线部分的交点并在两直线之间设定合适的平曲线。这通常是一个反复试验的过程，直到在工程师看来找到了考虑了工程和美学的最好线形。活动曲线规可以被用在这一阶段。活动曲线规是一个活动的可被弯曲成不同形状并用来画出不同线条的塑料导轨，利用它可以选出最合适的线形。曲线模板是一种能画出不同曲率和不同标准比例的圆曲线、三心复曲线和螺旋曲线的透明板。活动曲线规最早用于获得能满足纵坡、横断面、曲率和排水要求的手绘光滑曲线。这条手绘曲线通过标准模板变成一条更加清晰的曲线。
The availability of computer-based techniques has significantly enhanced this process since a proposed highway can be displayed on a monitor, enabling the designer to have a driver's eye view of both the horizontal and vertical alignments of the road. The designer can therefore change either or both alignments until the best alignment is achieved.
计算机技术的实用性极大地提高了这一过程的效率，因为设计的公路可以显示在屏幕上，从而使设计者有了驾驶者的视线效果，既可以看到平面线形，又可以看到纵面线形。因此设计者可以改动平/纵面线形或者同时改动两者直到获得最好的线形。
Lesson 9Design of the Alignment线形设计
The alignment of a highway is composed of vertical and horizontal elements. The vertical alignment includes straight (tangent) highway grades and the parabolic curves that connect these grades. The horizontal alignment includes the straight (tangent) sections of the roadway and the circular curves that connect their change in direction. 公路线形包括平曲线和竖曲线元素。竖曲线包括直坡线（切线）和连接这些直坡线的抛物线。平曲线包括公路的直线部分（切线）和连接两直线并转向的圆曲线。
The design of the alignment depends primarily on the design speed selected for the highway. The least costly alignment is one that generally takes the form of the natural topography. It is not always possible to select the lowest cost alternative because the designer has to adhere to certain standards that may not exist on the natural topography.
线形的设计取决于公路的设计速度。最经济的线形是沿着自然地形展线。现实中设计师往往不能选择造价最低的方案，因为他们必须遵循特定的技术标准，而这些标准在自然地形中也许难以达到。It is important that the alignment of a given section has consistent standards to avoid sudden changes in the vertical and horizontal layout of the highway. It is also important that both horizontal and vertical alignments be designed to complement each other, since this will result in a safer and more attractive highway.
重要的是给定部分的线形必须符合规范来避免公路在水平和竖直布局上产生突变。同样重要的是设计的平曲线和竖曲线要相互协调，因为这样才能设计出安全并更有吸引力的公路。
One factor that should be considered to achieve compatibility is the proper balancing of the grades of tangents with curvatures of horizontal curves and the location of horizontal and vertical curves with respect to each other. For example, a design that achieves horizontal curves with large radii at the expense of steep or long grades is a poor design. Similarly, if sharp horizontal curves are placed at or near the top of pronounced crest vertical curves or at or near the bottom of a pronounced sag vertical curve, a hazardous condition will be created at these sections of the highway. Thus, it is important that
coordination of the vertical and horizontal alignments be considered at the early stages of preliminary design.
为提高协调性应考虑的因素之一是保持直线坡度和曲线曲率均衡，处理好平曲线和竖曲线之间的相互位置。例如，大半径平曲线搭配长陡纵坡是一种较差的设计。同样，如果在凸形竖曲线的顶部及附近或在凹形竖曲线底部及附近设置小半径平曲线，那该路段就会变得很危险。因此，在初步设计阶段综合考虑平纵曲线很重要。The vertical alignment of a highway consists of straight sections known as grades, or tangents, connected by vertical curves. The design of the vertical alignment therefore involves the selection of suitable grades for the tangent sections and the appropriate length of the
vertical curves. The topography of the area through which the road traverses has a significant impact on the design of the vertical alignment.
公路竖曲线由纵坡线或称切线以及连接他们的竖曲线组成。因而，竖曲线的设计包括直线合适坡度的选择和竖曲线合适长度的设计。路线所穿越地区的地形对竖曲线的设计有十分重要的影响。
The effect of grade on the performance of heavy vehicles must be considered. The speed of a heavy vehicle can be significantly reduced
if the grade is steep and/or long. Note that steep grades not only affect the performance of heavy vehicles but also the performance of passenger cars. In order to limit the effect of grades on vehicular operation, the maximum grade on any highway should be selected judiciously.
必须考虑到纵坡对重载交通的影响。如果纵坡很陡且/或很长，
重交通车辆的车速将极大地降低。注意到坡度不仅影响重车的性能同时也影响轿车的性能。为限制纵坡对车辆运行的影响，任何公路都应恰当的选择最大坡度。
The selection of maximum grades for a highway depends on the design speed and the design vehicle. It is generally accepted that grades of 4 to 5 percent have little or no effect on passenger cars, except for those with high weight/horsepower ratios, such as those found in compact and subcompact cars. As the grade increases above 5 percent, however, speeds of passenger cars decrease on upgradesand
increase on downgrades.
公路最大坡度的选择取决于设计速度和设计车辆。普遍认为4%-5%的坡度对客车的影响不大或没有影响，除非是（质量/功率）较高的车，例如那些小型车或微型车。然而，当坡度大于5%时，客车上坡速度进一步降低，下坡速度进一步增加。
Grade has a greater impact on trucks than passenger cars. Extensive studies have been conducted, and results have shown that truck speed may increase up to 5 percent on downgraded and decrease by 7 percent on upgrades, depending on the percent and length of the grade.
坡度对卡车的影响大于客车。进行了广泛研究，其结果表明卡车下坡时速度增加超过5%，上坡时速度降低超过7%，取决于坡度和坡长。
Maximum grades have been established, based cm the operating characteristics of the design vehicle on the highway. These vary from 5 percent for a design speed of 70mi/h to between 7 and 12 percent for a design speed of 30 mi/h, depending on the type of highway. Note that the recommended maximum grades should not be used frequently, particularly when grades are long and the traffic includes a high percentage of trucks. On the other hand, when grade lengths are less than 500 ft and roads are one-way in the downgrade direction, maximum grades may be increased by up to 2 percent, particularly on low-volume rural highways.
最大坡度根据设计时就已确定的公路上汽车操控特点确定。按公路类型不同，最大坡度从设计速度70英里/小时的5%到设计速度30英里/小时的7%-12%不等。注意到推荐最大坡度不能频繁使用，尤其是纵坡较长而且车辆中卡车百分比较大时。另一方面，当坡长不足500英尺而且是下坡路段单行道时，最大纵坡可以增加超过2%，尤其在交通量小的乡村公路。
Minimum grades depend on the drainage conditions of the highway. Zero-percent grades may be used on uncurbed pavements with adequate cross slopes to laterally drain the surface water. Whenpavements are curbed, however, a longitudinal grade should be provided to facilitate the longitudinal flow of the surface water. It is customary to use a minimum of 0. 5 percent in such cases, although
this may be reduced to 0.3 percent on high-type pavement constructed on suitably crowned, firm ground.
最小坡度取决于公路排水条件。零坡可以用于不受限的有适当路拱横坡来排干路表水的路面。然而，当路面受限制时，纵坡应能促进路表水的纵向流动。这种情况下通常采用0.5%的最小纵坡，而在有合适铺装、周围硬化的高等级路面中可能减至0.3%。Vertical curves are used to provide a gradual change from one tangent grade to another so that vehicles may run smoothly as they traverse the highway. These curves are usually parabolic in shape. The expressions developed for minimum lengths of vertical curves are therefore based on the properties of a parabola. They are classified as crest vertical curves or sag vertical curves.
竖曲线通常用来使路线从一个坡度到另一个坡度的平缓过渡，这样在车辆穿越公路的时候可以平顺地行驶。这些曲线通常是抛物线形的。竖曲线最小长度公式取决于抛物线的性质。竖曲线又分为凹形竖曲线和凸形竖曲线。
The main criteria used for designing vertical curves are: (1) provision of minimum stopping sight distance;(2) adequate drainage;
(3) comfortable in operation; (4) pleasant appearance. The first criterion is the only criterion associated with crest vertical curves, whereas all four criteria are associated with sag vertical curves.
设计竖曲线的主要标准包括：（1）停车视距的要求；（2）充分考虑排水要求；（3）行车舒适性要求；（4）路线美观要求。凸形竖曲线只与第一个条件有关，而凹形竖曲线与四个条件都有关。
The horizontal alignment consists of straight sections of the road (known as tangents) connected by horizontal curves. The curves are usually segments of circles, which have radii that will provide for a smooth flow of traffic. The design of the horizontal alignment entails the determination of the minimum radius, the determination of the length of the curve, and the computation of the horizontal offsets from the tangents to the curve to facilitate locating the curve in the field. In some cases, to avoid a sudden change from a tangent with infinite radius to a curve of finite radius, a curve with radii varying from infinite to the radius of the circular curve is placed between the circular
curve and the tangent. Such a curve is known as a spiral or transition curve. There are four types of horizontal curves: simple, compound, reversed, and spiral.
平面线形由公路的直线部分和连接它的平曲线组成。平曲线通常是圆曲线段组成的，圆曲线有一定半径可以使车流平顺通过。因此，平面线形的设计需要确定最小半径、曲线长度以及从切线到曲线的平面支距，以利于曲线实地定线。有时，为了避免从直线曲率无限大到曲线有限曲率的突变，人们在圆曲线和直线间插入一段曲率从无限大到圆曲线曲率逐渐变化的曲线。这种曲线叫做螺旋曲线或缓和曲线。有四种类型的平曲线：单曲线、复曲线、反向曲线、螺旋曲线。
A sample curve is a segment of a circle while compound curves consist of two or more curves in succession, turning in the same direction, with any two successive curves having a common tangent point. These curves are mainly used to obtain desirable shapes of the horizontal alignment, particularly for at-grade intersections, ramps of interchanges, and highway sections in difficult topographic areas. To avoid abrupt changes in me alignment, the radii of any two consecutive simple curves that form a compound curve should not be widely different. AASHTO recommends that the ratio of the flatter radius to
the sharper radius at intersections should not be greater than 2:1 so drivers can adjust to sudden changes in curvature and speed. The maximum desirable ratio recommended for interchanges is 1.75:1, although 2:1 may be used.
单曲线由一段圆曲线组成，复曲线由两个或多个圆曲线连接而成，这些圆曲线转向相同且任何两相连圆曲线间有一个公切点。这些曲线主要用来获取较理想的平面线形，尤其在平面交叉、立体交叉和特殊地形路段。为避免线形突变，组成复曲线的两相连单曲线半径不应相差过大。AASHTO（美国国家公路与运输协会标准）规定，平面交叉口交大半径与较小半径之比不得超过2:1，这样就可以让司机适应曲率和速度的突变。立体交叉比较理想的曲率比是1.75:1，然而2:1也在用。
To provide a smooth transition from a flat curve to a sharp curve,
and to facilitate a reasonable deceleration rate on a series of curves of
decreasing radii, the length of each curve should observe minimum length requirements.
为使大曲率半径和小区率半径间实现平顺过渡、保证在一系列半径间小的圆曲线上的减速率，每个圆曲线的长度应满足最小长度的要求。
Reverse curves usually consist of two simple curves with equal radii turning in opposite directions with a common tangent. They are generally used to change the alignment of a highway.
反向曲线通常由两个有公切点的等半径反向单曲线组成反向曲
线常用于改变公路线形。
Reverse curves are seldom recommended because sudden changes to the alignment may result in drivers finding it difficult to keep in their lanes. When it is necessary to reverse the alignment, a preferable design consists of two simple horizontal curves, separated by a sufficient length of tangent between them, to achieve full superelevation. Alternatively, the simple curves may be separated by an equivalent length of spiral.
反向曲线很少被推荐使用，因为线形的突变可能会使司机感觉很难按车道行驶。必须设置反向曲线时，合理的做法是两个单曲线，中间插入一段足够长的直线以便完成全超高布置。作为一种选择，单曲线可以被等长度的回旋线隔开。
Transition curves are placed between tangents and circular curves or between two adjacent circular curves having substantially different radii. The use of transition curves provides a vehicle path that gradually increases or decreases the radial force as the vehicle enters or leaves a circular curve. If the transition curve is a spiral, the degree of curve between the tangent and the circular curve varies from zero at the tangent end to the degree of the circular curve at the curve end. When the transition is placed between two circular curves, the degree of curve varies from that of the first circular curve to that of the second circular curve.
缓和曲线设在直线和圆曲线或者两相邻不同直径圆曲线之间。缓和曲线的作用是在车辆驶入或驶出圆曲线时为其提供一条径向力
逐渐增大或逐渐减小的车道。如果缓和曲线是螺旋线，切线和圆曲
线间的曲率在直线端的零到曲线端的圆曲线曲率间变化。当缓和曲线设在两圆曲线之间时，缓和曲线曲率在第一个圆曲线曲率和第二个圆曲线曲率间变化。
Lesson 10 Grade Separations and Interchanges立体交叉和互通式
立体交叉
Intersections at grade can be eliminated by the use of
grade-separation structures that permit the cross flow of traffic at different levels without interruption. The advantage of such separation is the freedom from cross interference with resultant saving of time and increase in safety tor traffic movements.
平面交叉可以通过立体交叉来消除，这一构造允许车流在不同高度不间断的通行。这种分离式交通的优点是解除了交叉干扰、节省了时间、提高了交通安全性。
Grade separations and interchanges maybe warranted (1) aspart
of an express highway system designed to carry volumes of traffic; (2)to eliminate bottlenecks;(3)to prevent accidents; (4)where the topographyis such that other types of design are notfeasible; (5) where the volumes to be catered for would require the design of an intersection at grade ofunreasonable size; (6) where the mad user benefit of reducing delays at an at-grade intersection exceeds the c ost
of the improvement.
立体交叉和互通式立体交叉可被用于(1)作为高速公路的一部分来提高通行能力(2)消除道路瓶颈(3)预防事故(4)用于其他方案不可行的地形路段(5)车流量很大，若采用平面交叉超出合理尺寸(6)当用户因减少平面交叉延迟所得的收益多于升级费用时。
An interchange is a grade separation in which vehicles moving in one direction of flow may transfer by the use of connectingroadways. These connecting roadways at interchanges
are called ramps.
互通式立体交叉是一个立体分离式交叉，某一方向车流通过引道分离。引道在立体交叉中被称为匝道。
Many types and forms of interchanges and ramp layouts are used
in the United States. These general forms may be classified into six main types: T and Y interchanges; one-quadrant inter changes;
diamond interchanges, single-point urban interchanges, partial and
ful l cloverleaves; directional interchanges.
美国采用多种类型和形式的立交和匝道。这些形式大致分为六种主要类型：T型和Y型立交、单象限立交、菱形立交、单点式城市立交、部分和全苜蓿叶式立交定向式立交。
Fig. 10.1 shows typical layouts of interchanges at three-legged junctions. The geometry of theinterchange can be altered to favor certain movements by the provision of large turning radii and maybe modified to suit the topography of the site. The trumpet interchange has been found suitable for orthogonal or skewed intersections.
Fig.10.1a) favors the right turn on the freeway by the provision of a semidirect connecting ramp. Fig.10.1b) indicates an interchange where all turning movements are facilitated inthis way.
图10.1展示了三路交叉立交的典型设计。立交的几何尺寸可以按规定的大转弯半径改为特定形状，也可以按该处地形进行修改。人们发现喇叭形立交适合于正交和斜交路口。图10.1a)展示了高速公路通过半直接式匝道实现右转。图10.1b)展示了一种所有方向转弯都适用的立交。
Fig.10.1 c) depicts an example of a one-quadrant interchange. This configuration is convenientto reduce conflicts at me immediate location where the twomajor roads cross; however, the slow-speed design makes the one-quadrant interchange unacceptable for freeway conditions. This type of interchange is suitable for low-volume locations with few heavy vehicles such as a parkway interchange.
图10.1c)画出了单象限立体交叉的一个例子。这种结构很方便的减少了两主干道交叉位置附近的冲突。然而，基于低速的设计使单象限交叉不适于高速公路。这种立交适用于车流量小且重车较少的地区像景区道路立交。
The diamond interchange shown in Fig. 10. 1d) is adaptable to
both urban and rural use. The major flow is grade-separated , with turning movements to and from the minor flow achieved by
diverging and merging movements with through traffic on the minor flow. Only the minor flow directions have intersections at grade. In rural areas, this is generally acceptable owing to the light traffic on
theminor flow. In urban areas, the at-grade intersections generally
will require signalized control to prevent serious interference of
ramp traffic and the crossing arterial street. The design of the intersection should be such that the signalization required does not impair the capacity of thearterial street. To achieve this, widening of
the arterial may be necessary in the area of the interchange. Care
must also be taken in the design of the ramps so that traffic waiting
to leave the ramps will not back up into through lanes of the major flow.
菱形立交展示在图10.1d)中，适用于城市和乡村公路。主要交通流采用立体分离，而进入和驶离次要交通流的转弯车辆与次要交通流上的直行交通分流和合流运行。只有次要交通流方向有平面交叉。在乡村地区这通常是可以接受的，因为次要交通流中多为小车。在城区，交叉口通常需要信号控制以防严重干扰匝道和主干道大街。交叉口应该这样设计：设置的信号不能降低主要街道的通行能力。为实现这一目的，有必要在立交区域拓宽主路。在设计匝道时必须注意，保证等候离开匝道的车辆不会阻塞主要车流的直行车道。One disadvantage of the diamond interchange is the
possibility of illegal wrong-way turns, which can cause severe accidents. If the geometry of the intersection may lead to these turns, the designer should recommend channelization devices
and additional signing and pavement marking.
菱形立交的一个缺点是存在非法错路转弯的可能，这会导致严重事故。如果交叉口的几何形状有可能造成这种错路转弯，设计者应该设置渠化交通、额外标识和路面标线。
A newer type of interchange is the single-point urban interchange (SPUI). With the SPUI, all through and left turn movements converge into a single, signalized intersection area instead of thetwo separate intersection areas normally found
with other urban interchanges. The advantage of this design feature is that all intersecting movements can be served by a
single signal with, at most, onestop required to pass through the interchange. Proponents of the SPUI claim that it provides improved flows, safer operation, and reduced right-of-way
needs compared with other alternative configurations. The
SPUI is an unusual design requiring cross-road drivers to rely heavily on guide signing, pavement markings, and lane-use signing in order to travel safely through the intersection area. Designers of the SPUI will need to exercise special care to ensure that the intersection functions as it should.
一种新型的立体交叉叫单点立交。单点立交就是所有直行和左转车辆汇集到一个单一的信号交叉口而不是通常在其他交叉口所见到的两个分离的交叉区域。这一独特设计的优点是所有交叉车辆可以被一个信号灯服务，通过这一交叉口最多需停一次。单点式立交的支持者称，与其他可选结构形式相比，单点立交通行能力强、操作安全而且减少对先行权的需求。单点立交是一种特殊设计。驾驶员为安全通过交叉口需高度依赖引导标识、路面标线和车道用途标识。单点立交的设计者要特别留意来确保交叉口设施的完善。The partial and full cloverleaf interchanges are sometimes adopted in place of the diamond interchange. Traffic can leave the major flow either before or after the grade-separation structure, depending on the quadrant layout. The intersections at grade for theminor road are resent as for the diamond interchange, but the probability of illegal turning movements can be educed. By the provision of two on-ramps for each direction of the major route,
left-turn traffic on the minor route can be eliminated.
部分和全苜蓿叶式立交有时用来代替菱形立交。车辆按象限分布可以在交叉之前或之后离开主车流。交叉的次要车流按照菱形立交设计，但是可以降低非法错车转弯的可能。为主要道路的每个方向都设置匝道，而次要道路的左转车流被取消。
The more conventional arrangement of the full cloverleaf, which can be adapted to nonorthogonal layouts, eliminates at-grade crossings of all traffic streams for both major and minor roads. The ramps may be one-way, two-way, two-way separated, or two-way unseparated roads. Although all crossing movements are eliminated, the cloverleaf design has some disadvantages: (1) the layout requires large land areas;
(2) decelerating traffic attemping to leave the through lanes must weave with accelerating traffic entering the through lanes.
外文出处： 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题： JDBC接口技术 译文： JDBC是一种可用于执行SQL语句的JavaAPI（ApplicationProgrammingInterface应用程序设计接口）。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口，使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC，很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢？如果有，那么它们之间又是怎样的关系呢？ ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统（DBMS）中存取数据的，用C语言实现的，标准应用程序数据接口。通过ODBCAPI，应用程序可以存取保存在多种不同数据库管理系统（DBMS）中的数据，而不论每个DBMS使用了何种数据存储格式和编程接口。 1．ODBC的结构模型 ODBC的结构包括四个主要部分：应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口：屏蔽不同的ODBC数据库驱动器之间函数调用的差别，为用户提供统一的SQL编程接口。 驱动器管理器：为应用程序装载数据库驱动器。 数据库驱动器：实现ODBC的函数调用，提供对特定数据源的SQL请求。如果需要，数据库驱动器将修改应用程序的请求，使得请求符合相关的DBMS所支持的文法。 数据源：由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器，以便ODBC函数调用，但是数据库驱动器本身也执行ODBC函数调用，并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时，数据库驱动器能管理通信协议。当建立起与数据源的连接时，数据库驱动器便能处理应用系统向DBMS发出的请求，对分析或发自数据源的设计进行必要的翻译，并将结果返回给应用系统。 2．JDBC的诞生 自从Java语言于1995年5月正式公布以来，Java风靡全球。出现大量的用java语言编写的程序，其中也包括数据库应用程序。由于没有一个Java语言的API，编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥，比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱，越来越多的公司在Java程序开发上投入的精力日益增加，对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处，比如它并不容易使用，没有面向对象的特性等等，SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1．x 版本中，JDBC只是一个可选部件，到了JDK1．1公布时，SQL类包（也就是JDBCAPI）
转型衰退时期的土木工程研究 Sergios Lambropoulosa[1], John-Paris Pantouvakisb, Marina Marinellic 摘要 最近的全球经济和金融危机导致许多国家的经济陷入衰退，特别是在欧盟的周边。这些国家目前面临的民用建筑基础设施的公共投资和私人投资显著收缩，导致在民事特别是在民用建筑方向的失业。因此，在所有国家在经济衰退的专业发展对于土木工程应届毕业生来说是努力和资历的不相称的研究，因为他们很少有机会在实践中积累经验和知识，这些逐渐成为过时的经验和知识。在这种情况下，对于技术性大学在国家经济衰退的计划和实施的土木工程研究大纲的一个实质性的改革势在必行。目的是使毕业生拓宽他们的专业活动的范围，提高他们的就业能力。 在本文中，提出了土木工程研究课程的不断扩大，特别是在发展的光毕业生的潜在的项目，计划和投资组合管理。在这个方向上，一个全面的文献回顾，包括ASCE体为第二十一世纪，IPMA的能力的基础知识，建议在其他：显著增加所提供的模块和项目管理在战略管理中添加新的模块，领导行为，配送管理，组织和环境等；提供足够的专业训练五年的大学的研究；并由专业机构促进应届大学生认证。建议通过改革教学大纲为土木工程研究目前由国家技术提供了例证雅典大学。 1引言 土木工程研究（CES）蓬勃发展，是在第二次世界大战后。土木工程师的出现最初是由重建被摧毁的巨大需求所致，目的是更多和更好的社会追求。但是很快，这种演变一个长期的趋势，因为政府为了努力实现经济发展，采取了全世界的凯恩斯主义的理论，即公共基础设施投资作为动力。首先积极的结果导致公民为了更好的生活条件（住房，旅游等）和增加私人投资基础设施而创造机会。这些现象再国家的发展中尤为为明显。虽然前景并不明朗（例如，世界石油危机在70年代），在80年代领先的国家采用新自由主义经济的方法（如里根经济政策），这是最近的金融危机及金融危机造成的后果（即收缩的基础设施投资，在技术部门的高失业率），消除发展前途无限的误区。 技术教育的大学所认可的大量研究土木工程部。旧学校拓展专业并且新的学校建成，并招收许多学生。由于高的职业声望，薪酬，吸引高质量的学校的学生。在工程量的增加和科学技术的发展，导致到极强的专业性，无论是在研究还是工作当中。结构工程师，液压工程师，交通工程师等，都属于土木工程。试图在不同的国家采用专业性的权利，不同的解决方案，，从一个统一的大学学历和广泛的专业化的一般职业许可证。这个问题在许多其他行业成为关键。国际专业协会的专家和机构所确定的国家性检查机构，经过考试后，他们证明不仅是行业的新来者，而且专家通过时间来确定进展情况。尽管在很多情况下，这些证书虽然没有国家接受，他们赞赏和公认的世界。 在试图改革大学研究（不仅在土木工程）更接近市场需求的过程中，欧盟确定了1999博洛尼亚宣言，它引入了一个二能级系统。第一级度（例如，一个三年的学士）是进入
第一课 土木工程学土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 领域。因为包含范围太广，土木工程学又被细分为大量的技术专业。不同类型的工程需要多种不同土木工程专业技术。一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。 贯穿任何给定项目，土木工程师都需要大量使用计算机。计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。计算机成为了现代土木工程师的必备品，因为它使得工程师能有效地掌控所需的大量数据从而确定建造一项工程的最佳方法。 结构工程学。在这一专业领域，土木工程师规划设计各种类型的结构，包括桥梁，大坝，发电厂，设备支撑，海面上的特殊结构，美国太空计划，发射塔，庞大的天文和无线电望远镜，以及许多其他种类的项目。结构工程师应用计算机确定一个结构必须承受的力：自重，风荷载和飓风荷载，建筑材料温度变化引起的胀缩，以及地震荷载。他们也需确定不同种材料如钢筋，混凝土，塑料，石头，沥青，砖，铝或其他建筑材料等的复合作用。 水利工程学。土木工程师在这一领域主要处理水的物理控制方面的种种问题。他们的项目用于帮助预防洪水灾害，提供城市用水和灌溉用水，管理控制河流和水流物，维护河滩及其他滨水设施。此外，他们设计和维护海港，运河与水闸，建造大型水利大坝与小型坝，以及各种类型的围堰，帮助设计海上结构并且确定结构的位置对航行影响。 岩土工程学。专业于这个领域的土木工程师对支撑结构并影响结构行为的土壤和岩石的特性进行分析。他们计算建筑和其他结构由于自重压力可能引起的沉降，并采取措施使之减少到最小。他们也需计算并确定如何加强斜坡和填充物的稳定性以及如何保护结构免受地震和地下水的影响。 环境工程学。在这一工程学分支中，土木工程师设计，建造并监视系统以提供安全的饮用水，同时预防和控制地表和地下水资源供给的污染。他们也设计，建造并监视工程以控制甚至消除对土地和空气的污染。他们建造供水和废水处理厂，设计空气净化器和其他设备以最小化甚至消除由工业加工、焚化及其他产烟生产活动引起的空气污染。他们也采用建造特殊倾倒地点或使用有毒有害物中和剂的措施来控制有毒有害废弃物。此外，工程师还对垃圾掩埋进行设计和管理以预防其对周围环境造成污染。
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
项目成本控制 一、引言 项目是企业形象的窗口和效益的源泉。随着市场竞争日趋激烈，工程质量、文明施工要求不断提高，材料价格波动起伏，以及其他种种不确定因素的影响，使得项目运作处于较为严峻的环境之中。由此可见项目的成本控制是贯穿在工程建设自招投标阶段直到竣工验收的全过程，它是企业全面成本管理的重要环节，必须在组织和控制措施上给于高度的重视，以期达到提高企业经济效益的目的。 二、概述 工程施工项目成本控制，指在项目成本在成本发生和形成过程中，对生产经营所消耗的人力资源、物资资源和费用开支，进行指导、监督、调节和限制，及时预防、发现和纠正偏差从而把各项费用控制在计划成本的预定目标之内，以达到保证企业生产经营效益的目的。 三、施工企业成本控制原则 施工企业的成本控制是以施工项目成本控制为中心，施工项目成本控制原则是企业成本管理的基础和核心，施工企业项目经理部在对项目施工过程进行成本控制时，必须遵循以下基本原则。 3.1 成本最低化原则。施工项目成本控制的根本目的，在于通过成本管理的各种手段，促进不断降低施工项目成本，以达到可能实现最低的目标成本的要求。在实行成本最低化原则时，应注意降低成本的可能性和合理的成本最低化。一方面挖掘各种降低成本的能力，使可能性变为现实；另一方面要从实际出发，制定通过主观努力可能达到合理的最低成本水平。 3.2 全面成本控制原则。全面成本管理是全企业、全员和全过程的管理，亦称“三全”管理。项目成本的全员控制有一个系统的实质性内容，包括各部门、各单位的责任网络和班组经济核算等等，应防止成本控制人人有责，人人不管。项目成本的全过程控制要求成本控制工作要随着项目施工进展的各个阶段连续 进行，既不能疏漏，又不能时紧时松，应使施工项目成本自始至终置于有效的控制之下。 3.3 动态控制原则。施工项目是一次性的，成本控制应强调项目的中间控制，即动态控制。因为施工准备阶段的成本控制只是根据施工组织设计的具体内容确
第一课土木工程学 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 领域。因为包含范围太广，土木工程学又被细分为大量的技术专业。不同类型的工程需要多种不同土木工程专业技术。一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。 贯穿任何给定项目，土木工程师都需要大量使用计算机。计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。计算机成为了现代土木工程师的必备品，因为它使得工程师能有效地掌控所需的大量数据从而确定建造一项工程的最佳方法。 结构工程学。在这一专业领域，土木工程师规划设计各种类型的结构，包括桥梁，大坝，发电厂，设备支撑，海面上的特殊结构，美国太空计划，发射塔，庞大的天文和无线电望远镜，以及许多其他种类的项目。结构工程师应用计算机确定一个结构必须承受的力：自重，风荷载和飓风荷载，建筑材料温度变化引起的胀缩，以及地震荷载。他们也需确定不同种材料如钢筋，混凝土，塑料，石头，沥青，砖，铝或其他建筑材料等的复合作用。 水利工程学。土木工程师在这一领域主要处理水的物理控制方面的种种问题。他们的项目用于帮助预防洪水灾害，提供城市用水和灌溉用水，管理控制河流和水流物，维护河滩及其他滨水设施。此外，他们设计和维护海港，运河与水闸，建造大型水利大坝与小型坝，以及各种类型的围堰，帮助设计海上结构并且确定结构的位置对航行影响。 岩土工程学。专业于这个领域的土木工程师对支撑结构并影响结构行为的土壤和岩石的特性进行分析。他们计算建筑和其他结构由于自重压力可能引起的沉降，并采取措施使之减少到最小。他们也需计算并确定如何加强斜坡和填充物的稳定性以及如何保护结构免受地震和地下水的影响。 环境工程学。在这一工程学分支中，土木工程师设计，建造并监视系统以提供安全的饮用水，同时预防和控制地表和地下水资源供给的污染。他们也设计，建造并监视工程以控制甚至消除对土地和空气的污染。
a common way to construct steel truss and prestressed concrete cantilever spans is to counterbalance each cantilever arm with another cantilever arm projecting the opposite direction,forming a balanced cantilever. they attach to a solid foundation ,the counterbalancing arms are called anchor arms /thus,in a bridge built on two foundation piers,there are four cantilever arms ,two which span the obstacle,and two anchor arms which extend away from the obstacle,because of the need for more strength at the balanced cantilever's supports ,the bridge superstructure often takes the form of towers above the foundation piers .the commodore barry bridge is an example of this type of cantilever bridge 一种常见的方法构造钢桁架和预应力混凝土悬臂跨度是每一个悬臂抗衡预测相反的方向臂悬臂，形成一个平衡的悬臂。他们重视了坚实的基础，制约武器被称为锚武器/因此，在两个基础上建一座桥桥墩，有四个悬臂式武器，这两者之间跨越的障碍，和两个锚武器哪个延长距离的障碍，因为为更多的在平衡悬臂的支持力量的需要，桥梁上部结构往往表现为塔墩基础之上形成的准将巴里大桥是这种类型的例子悬臂桥 steel truss cantilever support loads by tension of the upper members and compression of the lower ones .commonly ,the structure distributes teh tension via teh anchor arms to the outermost supports ,while the compression is carried to the foundation beneath teh central towers .many truss cantilever bridges use pinned joints and are therefore statically determinate with no members carrying mixed loads 钢桁架悬臂由上层成员和下层的紧张压缩支持负载。通常，结构分布通过锚武器的最外层的支持紧张，而压缩抬到下方的中央塔的基础。桁架悬臂许多桥梁使用固定的关节，是静定，没有携带混合负载的成员，因此 prestressed concrete balanced cantilever bridges are often built using segmental construction .some steel arch bridges are built using pure cantilever spans from each sides,with neither falsework below nor temporary supporting towers and cables above ,these are then joined with a pin,usually after forcing the union point apart ,and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge .such unsupported construction is only possible where appropriate rock is available to support the tension in teh upper chord of the span during construction ,usually limiting this method to the spanning of narrow canyons 预应力混凝土平衡悬臂桥梁往往建立使用段施工。一些钢拱桥是使用各方面的纯悬臂跨度既无假工作下面也临时支撑塔和电缆上面，这些都是再加入了一根针，通常在迫使工会点外，当插孔删除，并添加桥梁甲板桥成为桁架拱桥，这种不支持的建设，才可能在适当情况下的岩石可用于支持在施工期间的跨度弦上的张力，通常限制这狭隘的峡谷跨越方法 an arch bridge is a bridge with abutments at each end shaped as a curved arch .arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side .a viaduct may be made from a series of arches ,although other more economical structures are typically used today 在拱桥桥台的桥梁，是一个在一个弧形拱状，每年年底。拱桥通过转移到由部分在两边的桥台水平推
第一部分必须掌握，第二部分尽量掌握 第一部分： 1 Finite Element Method 有限单元法 2 专业英语Specialty English 3 水利工程Hydraulic Engineering 4 土木工程Civil Engineering 5 地下工程Underground Engineering 6 岩土工程Geotechnical Engineering 7 道路工程Road (Highway) Engineering 8 桥梁工程Bridge Engineering 9 隧道工程Tunnel Engineering 10 工程力学Engineering Mechanics 11 交通工程Traffic Engineering 12 港口工程Port Engineering 13 安全性safety 17木结构timber structure 18 砌体结构masonry structure 19 混凝土结构concrete structure 20 钢结构steelstructure 21 钢-混凝土复合结构steel and concrete composite structure 22 素混凝土plain concrete 23 钢筋混凝土reinforced concrete 24 钢筋rebar 25 预应力混凝土pre-stressed concrete 26 静定结构statically determinate structure 27 超静定结构statically indeterminate structure 28 桁架结构truss structure 29 空间网架结构spatial grid structure 30 近海工程offshore engineering 31 静力学statics 32运动学kinematics 33 动力学dynamics 34 简支梁simply supported beam 35 固定支座fixed bearing 36弹性力学elasticity 37 塑性力学plasticity 38 弹塑性力学elaso-plasticity 39 断裂力学fracture Mechanics 40 土力学soil mechanics 41 水力学hydraulics 42 流体力学fluid mechanics 43 固体力学solid mechanics 44 集中力concentrated force 45 压力pressure 46 静水压力hydrostatic pressure 47 均布压力uniform pressure 48 体力body force 49 重力gravity 50 线荷载line load 51 弯矩bending moment 52 torque 扭矩53 应力stress 54 应变stain 55 正应力normal stress 56 剪应力shearing stress 57 主应力principal stress 58 变形deformation 59 内力internal force 60 偏移量挠度deflection 61 settlement 沉降 62 屈曲失稳buckle 63 轴力axial force 64 允许应力allowable stress 65 疲劳分析fatigue analysis 66 梁beam 67 壳shell 68 板plate 69 桥bridge 70 桩pile 71 主动土压力active earth pressure 72 被动土压力passive earth pressure 73 承载力load-bearing capacity 74 水位water Height 75 位移displacement 76 结构力学structural mechanics 77 材料力学material mechanics 78 经纬仪altometer 79 水准仪level 80 学科discipline 81 子学科sub-discipline 82 期刊journal ,periodical 83文献literature 84 ISSN International Standard Serial Number 国际标准刊号 85 ISBN International Standard Book Number 国际标准书号 86 卷volume 87 期number 88 专着monograph 89 会议论文集Proceeding 90 学位论文thesis, dissertation 91 专利patent 92 档案档案室archive 93 国际学术会议conference 94 导师advisor 95 学位论文答辩defense of thesis 96 博士研究生doctorate student 97 研究生postgraduate 98 EI Engineering Index 工程索引 99 SCI Science Citation Index 科学引文索引 100ISTP Index to Science and Technology Proceedings 科学技术会议论文集索引 101 题目title 102 摘要abstract 103 全文full-text 104 参考文献reference 105 联络单位、所属单位affiliation 106 主题词Subject 107 关键字keyword 108 ASCE American Society of Civil Engineers 美国土木工程师协会 109 FHWA Federal Highway Administration 联邦公路总署
I / 11 本科毕业设计外文翻译 <2018届） 论文题目基于WEB 的J2EE 的信息系统的方法研究 作者姓名[单击此处输入姓名] 指导教师[单击此处输入姓名] 学科(专业 > 所在学院计算机科学与技术学院 提交日期[时间 ]
基于WEB的J2EE的信息系统的方法研究 摘要：本文介绍基于工程的Java开发框架背后的概念，并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复，而且并不总是符合最佳实践，所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式，代表有效解决办法的工具。开发框架提供：<1）从用户界面到数据集成的应用程序开发堆栈；<2）一个架构，基本环境及他们的相关技术，这些技术用来使用其他一些框架。架构定义了一个开发方法，其目的是协助客户开发工程。 关键词：J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台，以实现他们的用户界面，科学分析，分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此，WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平，使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下，开源框架没有提供常见问题的一个解决方案。出于这个原因，开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架，该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架，本文提出了新的架构，基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法，其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求，也
专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类： 1.抗弯矩框架。 2.支撑框架，包括偏心支撑框架。 3.剪力墙，包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。这并
不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。
土木工程专业英语课文原 文及对照翻译 Newly compiled on November 23, 2020
Civil Engineering Civil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities. 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities. 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 The word civil derives from the Latin for citizen. In 1782, Englishman John Smeaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineering has often been used to refer to engineers who build public facilities, although the field is much broader 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 Scope. Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills of many kinds of civil engineer specialists may be needed. When a project begins, the site is surveyed and mapped by civil engineers who locate utility placement—water, sewer, and power lines. Geotechnical specialists perform soil experiments to determine if the earth can bear the weight of the project. Environmental specialists study the project’s impact on the local area: the potential for air and
(1)Concrete and reinforced concrete are used as building materials in every country. In many, including Canada and the United States, reinforced concrete is a dominant structural material in engineered construction. (1)混凝土和钢筋混凝土在每个国家都被用作建筑材料。在许多国家，包括加拿大和美国，钢筋混凝土是一种主要的工程结构材料。 (2)The universal nature of reinforced concrete construction stems from the wide availability of reinforcing bars and the constituents of concrete, gravel, sand, and cement, the relatively simple skills required in concrete construction. (2) 钢筋混凝土建筑的广泛存在是由于钢筋和制造混凝土的材料，包括石子，沙，水泥等，可以通过多种途径方便的得到，同时兴建混凝土建筑时所需要的技术也相对简单。 (3)Concrete and reinforced concrete are used in bridges, building of all sorts, underground structures, water tanks, television towers, offshore oil exploration and production structures, dams, and even in ships. (3)混凝土和钢筋混凝土被应用于桥梁，各种形式的建筑，地下结构，蓄水池，电视塔，海上石油平台，以及工业建筑，大坝，甚至船舶等。 (4)Reinforce concrete structures consist of a series of individual members that interact to support the loads placed on the structure. The floor of concrete buildings is often built of concrete joist-slab construction. (4)钢筋混凝土结构由一系列单独构件组成，这些构件通过相互作用共同抵抗施加在结构上的荷载。混凝土建筑的楼层通常采用肋梁楼盖的形式。 (5)A series of parallel ribs or joists support the load from the top slab. The reactions supporting the joists apply load to the beams, which in turn are supported by the columns. (5)一系列的平行梁肋或次梁抵抗其上楼板传来的荷载，次梁的反力作为荷载施加在主粱上，主粱则支承在柱上。 (6)The slab transfers load laterally to the joists, and serves as the top flange of the joists, which act as T-shaped beams that transmit the load to the beams running at right angles to the joists. (6)楼板将荷载垂直传递给次梁，并且作为上翼缘和次梁一起形成T形截面梁，将荷载传递给与次梁正交的主粱。 (7)Some floors of have a slab-and-beam design in which the slab spans between beams, which in turn apply loads to the columns. (7)一些楼层被设计成梁板结构，即楼板直接支承在相邻的主粱上，主粱再将荷载传递到柱上。 (8)Concrete is strong in compression but weak in tension. As a result, cracks develop whenever loads, or restrained shrinkage or temperature changes, give rise to tensile stresses in excess of the tensile strength of the concrete. (8)混凝土的抗压能力很强但抗拉能力很弱。因此，当荷载、受约束的收缩或温度变化所引起的拉应力超过其抗拉强度时，混凝土中的裂缝就会开展。 (9)The construction of a reinforced concrete member involves building a form or mould in the shape of the member being built. The form must be strong enough to support the weight and hydrostatic pressure of the wet concrete. (9)钢筋混凝土构件的制作需要一个与构件形状相同的模子，其必须具有足够的强度以抵抗湿混凝土的重量和流动压力。 (10)The reinforcement is placed in this form and held in place during the concreting