搜档网
当前位置:搜档网 › 道路与桥梁专业外文翻译、中英对照

道路与桥梁专业外文翻译、中英对照

道路与桥梁专业外文翻译、中英对照
道路与桥梁专业外文翻译、中英对照

本科毕业设计(论文)

专业外文翻译

专业名称:土木工程专业(道路与桥梁)年级班级:道桥08-5班

学生姓名:

指导教师:

二○一二年五月十八日

Geometric Design of Highways

The road is one kind of linear construction used for travel. It is made of the roadbed, the road surface, the bridge, the culvert and the tunnel. In addition, it also has the crossing of lines, the protective project and the traffic engineering and the route facility.

The roadbed is the base of road surface, road shoulder, side slope, side ditch foundations. It is stone material structure, which is designed according to route's plane position .The roadbed, as the base of travel, must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding.

The road surface is the surface of road. It is single or complex structure built with mixture. The road surface require being smooth, having enough intensity, good stability and anti-slippery function. The quality of road surface directly affects the safe, comfort and the traffic.

Highway geometry designs to consider Highway Horizontal Alignment, Vertical Alignment two kinds of linear and cross-sectional composition of coordination, but also pay attention to the smooth flow of the line of sight, etc. Determine the road geometry, consider the topography, surface features, rational use of land and environmental protection factors, to make full use of the highway geometric components of reasonable size and the linear combination.

1.Alignment Design

The alignment of a road is shown on the plane view and is a series of straight lines called tangents connected by circular. In modern practice it is common to interpose transition or spiral curves between tangents and circular curves.

Alignment must be consistent. Sudden changes from flat to sharp curves and long tangents followed by sharp curves must be avoided; otherwise, accident hazards will be created. Likewise, placing circular curves of different radii end to end (compound curves) or having a short tangent between two curves is poor practice unless suitable transitions between them are provided. Long, flat curves are preferable at all times, as they are pleasing in appearance and decrease possibility of future

obsolescence. However, alignment without tangents is undesirable on two-lane roads because some drivers hesitate to pass on curves. Long, flat curves should be used for small changes in direction, as short curves appear as “kink”. Also horizontal and vertical alignment must be considered together, not separately. For example, a sharp horizontal curve beginning near a crest can create a serious accident hazard.

A vehicle traveling in a curved path is subject to centrifugal force. This is balanced by an equal and opposite force developed through cannot exceed certain maximums, and these controls place limits on the sharpness of curves that can be used with a design speed. Usually the sharpness of a given circular curve is indicated by its radius. However, for alignment design, sharpness is commonly expressed in terms of degree of curve, which is the central angle subtended by a 100-ft length of curve. Degree of curve is inversely proportional to the radius.

Tangent sections of highways carry normal cross slope; curved sections are super elevated. Provision must be made for gradual change from one to the other. This usually involves maintaining the center line of each individual roadway at profile grade while raising the outer edge and lowering the inner edge to produce the desired super elevation is attained some distance beyond the point of curve.

If a vehicle travels at high speed on a carefully restricted path made up of tangents connected by sharp circular curve, riding is extremely uncomfortable. As the car approaches a curve, super elevation begins and the vehicle is tilted inward, but the passenger must remain vertical since there is on centrifugal force requiring compensation. When the vehicle reaches the curve, full centrifugal force develops at once, and pulls the rider outward from his vertical position. To achieve a position of equilibrium he must force his body far inward. As the remaining super elevation takes effect, further adjustment in position is required. This process is repeated in reverse order as the vehicle leaves the curve. When easement curves are introduced, the change in radius from infinity on the tangent to that of the circular curve is effected gradually so that centrifugal force also develops gradually. By careful application of super elevation along the spiral, a smooth and gradual application of centrifugal force can be had and the roughness avoided.

Easement curves have been used by the railroads for many years, but their adoption by highway agencies has come only recently. This is understandable. Railroad trains must follow the precise alignment of the tracks, and the discomfort described here can be avoided only by adopting easement curves. On the other hand, the motor-vehicle operator is free to alter his lateral position on the road and can provide his own easement curves by steering into circular curves gradually. However, this weaving within a traffic lane (but sometimes into other lanes) is dangerous. Properly designed easement curves make weaving unnecessary. It is largely for safety reasons, then, that easement curves have been widely adopted by highway agencies.

For the same radius circular curve, the addition of easement curves at the ends changes the location of the curve with relation to its tangents; hence the decision regarding their use should be made before the final location survey. They point of beginning of an ordinary circular curve is usually labeled the PC (point of curve) or BC (beginning of curve). Its end is marked the PT (point of tangent) or EC (end of curve). For curves that include easements, the common notation is, as stationing increases: TS (tangent to spiral), SC (spiral to circular curve), CS (circular curve to spiral), and ST (spiral go tangent).

On two-lane pavements provision of a wilder roadway is advisable on sharp curves. This will allow for such factors as (1) the tendency for drivers to shy away from the pavement edge, (2) increased effective transverse vehicle width because the front and rear wheels do not track, and (3) added width because of the slanted position of the front of the vehicle to the roadway centerline. For 24-ft roadways, the added width is so small that it can be neglected. Only for 30mph design speeds and curves sharper than 22°does the added width reach 2 ft. For narrower pavements, however, widening assumes importance even on fairly flat curves. Recommended amounts of and procedures for curve widening are given in Geometric Design for Highways.

2. Grades

The vertical alignment of the roadway and its effect on the safe and economical operation of the motor vehicle constitute one of the most important features of road design. The vertical alignment, which consists of a series of straight lines connected by vertical parabolic or circular curves, is known as the “grade line.” When the grade

line is increasing from the horizontal it is known as a “plus grade,”and when it is decreasing from the horizontal it is known as a “minus grade.” In analyzing grade and grade controls, the designer usually studies the effect of change in grade on the centerline profile.

In the establishment of a grade, an ideal situation is one in which the cut is balanced against the fill without a great deal of borrow or an excess of cut to be wasted. All hauls should be downhill if possible and not too long. The grade should follow the general terrain and rise and fall in the direction of the existing drainage. In mountainous country the grade may be set to balance excavation against embankment as a clue toward least overall cost. In flat or prairie country it will be approximately parallel to the ground surface but sufficiently above it to allow surface drainage and, where necessary, to permit the wind to clear drifting snow. Where the road approaches or follows along streams, the height of the grade line may be dictated by the expected level of flood water. Under all conditions, smooth, flowing grade lines are preferable to choppy ones of many short straight sections connected with short vertical curves.

Changes of grade from plus to minus should be placed in cuts, and changes from a minus grade to a plus grade should be placed in fills. This will generally give a good design, and many times it will avoid the appearance of building hills and producing depressions contrary to the general existing contours of the land. Other considerations for determining the grade line may be of more importance than the balancing of cuts and fills.

Urban projects usually require a more detailed study of the controls and finer adjustment of elevations than do rural projects. It is often best to adjust the grade to meet existing conditions because of the additional expense of doing otherwise.

In the analysis of grade and grade control, one of the most important considerations is the effect of grades on the operating costs of the motor vehicle. An increase in gasoline consumption and a reduction in speed are apparent when grades are increase in gasoline consumption and a reduction in speed is apparent when grades are increased. An economical approach would be to balance the added annual cost of grade reduction against the added annual cost of vehicle operation without grade reduction. An accurate solution to the problem depends on the knowledge of traffic

volume and type, which can be obtained only by means of a traffic survey.

While maximum grades vary a great deal in various states, AASHTO recommendations make maximum grades dependent on design speed and topography. Present practice limits grades to 5 percent of a design speed of 70 mph. For a design speed of 30 mph, maximum grades typically range from 7 to 12 percent, depending on topography. Wherever long sustained grades are used, the designer should not substantially exceed the critical length of grade without the provision of climbing lanes for slow-moving vehicles. Critical grade lengths vary from 1700 ft for a 3 percent grade to 500 ft for an 8 percent grade.

Long sustained grades should be less than the maximum grade on any particular section of a highway. It is often preferred to break the long sustained uniform grade by placing steeper grades at the bottom and lightening the grade near the top of the ascent. Dips in the profile grade in which vehicles may be hidden from view should also be avoided. Maximum grade for highway is 9 percent. Standards setting minimum grades are of importance only when surface drainage is a problem as when water must be carried away in a gutter or roadside ditch. In such instances the AASHTO suggests a minimum of 0.35%.

3. Sight Distance

For safe vehicle operation, highway must be designed to give drivers a sufficient distance or clear version ahead so that they can avoid unexpected obstacles and can pass slower vehicles without danger. Sight distance is the length of highway visible ahead to the driver of a vehicle. The concept of safe sight distance has two facets: “stopping” (or “no passing”) and “passing”.

At times large objects may drop into a roadway and will do serious damage to a motor vehicle that strikes them. Again a car or truck may be forced to stop in the traffic lane in the path of following vehicles. In dither instance, proper design requires that such hazards become visible at distances great enough that drivers can stop before hitting them. Further more, it is unsafe to assume that one oncoming vehicle may avoid trouble by leaving the lane in which it is traveling, for this might result in loss of control or collision with another vehicle.

Stopping sight distance is made up of two elements. The first is the distance

traveled after the obstruction comes into view but before the driver applies his brakes. During this period of perception and reaction, the vehicle travels at its initial velocity. The second distance is consumed while the driver brakes the vehicle to a stop. The first of these two distances is dependent on the speed of the vehicle and the perception time and brake-reaction time of the operator. The second distance depends on the speed of the vehicle; the condition of brakes, times, and roadway surface; and the alignment and grade of the highway.

On two-lane highways, opportunity to pass slow-moving vehicles must be provided at intervals. Otherwise capacity decreases and accidents increase as impatient drivers risk head-on collisions by passing when it is unsafe to do so. The minimum distance ahead that must be clear to permit safe passing is called the passing sight distance. In deciding whether or not to pass another vehicle, the driver must weigh the clear distance available to him against the distance required to carry out the sequence of events that make up the passing maneuver. Among the factors that will influence his decision are the degree of caution that he exercises and the accelerating ability of his vehicle. Because humans differ markedly, passing practices, which depend largely on human judgment and behavior rather than on the laws of mechanics, vary considerably among drivers.

The geometric design is to ensure highway traffic safety foundation, the highway construction projects around the other highway on geometric design, therefore, in the geometry of the highway design process, if appear any unsafe potential factors, or low levels of combination of design, will affect the whole highway geometric design quality, and the safety of the traffic to bring adverse impact. So, on the geometry of the highway design must be focus on.

公路几何设计

公路是供汽车或其他车辆行驶的一种线形带状结构体。它是由路基、路面、桥梁、涵洞和隧道组成。此外,它还有路线交叉、防护工程和交通工程及沿线设施。

路基是路面、路肩、边坡、边沟等部分的基础。它是按照路线的平面位置在地面上开挖和填筑成的土石料构造物。路基作为行车部分的基础,必须保证它有足够的强度和稳定性,可以防止水及其他自然灾害的侵蚀。

路面是公路表面的部分。它是用混合料铺筑的单层或多层结构物。路面要求光滑,具有足够的强度,稳定性好和抗湿滑功能。路面质量的好环,直接影响到行车的安全性、舒适性和通行。

公路几何线形设计要考虑公路平面线形、纵断面线形两种线形以及横断面的组成相协调,还要注意视距的畅通等等。确定公路几何线形时,在考虑地形、地物、土地的合理利用及环境保护因素时,要充分利用公路几何组成部分的合理尺寸和线形组合。

1、线形设计

道路的线形反映在平面图上是由一系列的直线和与直线相连的圆曲线构成的。现代设计时常在直线与圆曲线之间插入缓和曲线。

线形应是连续的,应避免平缓线形到小半径曲线的突变或者长直线末端与小半径曲线相连接的突然变化,否则会发生交通事故。同样,不同半径的圆弧首尾相接(曲线)或在两半径不同的圆弧之间插入短直线都是不良的线形,除非在圆弧之间插入缓和曲线。长而平缓的曲线在任何时候都是可取的,因为这种曲线线形优美,将来也不会废弃。然而,双向道路线形全由曲线构成也是不理想的,因为一些驾驶员通过曲线路段时总是犹豫。长而缓的曲线应用在拐角较小的地方。如果采用短曲线,则会出现“扭结”。另外,线路的平、纵断面设计应综合考虑,而不应只顾其一,不顾其二,例如,当平曲线的起点位于竖曲线的顶点附近时将会产生严重的交通事故。

行驶在曲线路段上的车辆受到离心力的作用,就需要一个大小相同方向相反的由超高和侧向磨擦提供的力抵消它,这些控制值对于某一规定设计车速可能采用曲线的曲率作了限制。通常情况下,某一圆曲线的曲率是由其半径来体现的。而对于线形设计而言,曲率常常通过曲线的程度来描述,即100英尺长的曲线所

对应的中心角,曲线的程度与曲线的半径成反比。

公路的直线地段设置正常的路拱,而曲线地段则设置超高,在正常断面与超高断面之间必须设置过渡渐变路段。通常的做法是维持道路每一条中线设计标高不变,通过抬高外侧边缘,降低内侧边缘以形成所需的超高,对于直线与圆曲线直接相连的线形,超高应从未到达曲线之前的直线上开始,在曲线顶点另一端一定距离以外达到全部超高。

如果车辆以高速度行驶在直线与小半径的圆曲线相连的路段,行车是极不舒服。汽车驶近曲线路段时,超高开始,车辆向内侧倾斜,但乘客须维持身体的垂直状态,因为此时未受到离心力的作用。当汽车到达曲线路段时,离心力突然产生,迫使乘客向外倾斜,为了维持平衡,乘客必须迫使自己的身体向内侧倾斜。由于剩余超高发挥作用,乘客须作进一步的姿势的调整。当汽车离开曲线时,上述过程刚好相反。插入缓和曲线后,半径从无穷大逐渐过渡到圆曲线上的某一固定值,离心力逐渐增大,沿缓和曲线心设置超高,离心力平稳逐渐增加,避免了行车颠簸。

缓和曲线在铁路上已经使用多年,但在公路上最近才得以应用,这是可以理解的。火车必须遵循精确的运行轨道,采用缓和曲线后,上述那种不舒服的感觉才能消除。然而,汽车司机在公路上可以随意改变侧向位置,通过迂迴进入圆曲线来为自己提供缓和曲线。但是在一个车道上(有时在其他车道上)做这种迂迴行驶是非常危险的。设计合理的缓和曲线使得上述迂迴没有必要。主要是出于安全原因,公路部门广泛采用了缓和曲线。

对于半径相同的圆曲线来说,在未端加上缓和曲线就会改变曲线与直线的相关位置,因此应在最终定线勘测之前应决定是否采用缓和曲线。一般曲线的起点标为PC或BC,终点标为PT或EC。对含有缓和曲线的曲线,通常的标记配置增为:TC、SC、CS和ST。对于双向道路,急弯处应增加路面宽度,这主要基于以下因素:(1)驾驶员害怕驶出路面边缘;(2)由于车辆前轮和后轮的行驶轨迹不同,车辆有效横向宽度加大;(3)车辆前方相对于公路中线倾斜而增加的宽度。对于宽度为24英尺的道路,增加的宽度很小,可以忽略。只有当设计车速为30mile/h,且曲度大于22℃时,加宽可达2英尺。然而,对于较窄的路面,即使是在较平缓的曲线路段上,加宽也是很重要推荐加宽值及加宽设计见《公路线形设计》

2、纵坡线

公路的竖向线形及其对车辆运行的安全性和经济性的影响构成了公路设计中最重要的要素之一。竖向线形由直线和竖向抛物线或圆曲线组成,称为纵坡线。纵坡线从水平线逐渐上升时称为坡度变化的影响。

在确定坡度时最理想的情况是挖方与填方平衡,没有大量的借方或弃方。所有运土都尽可能下坡运并且距离不长,坡度应随地形而变,并且与既有排水系统的升、降方向一致。在山区,坡度要使得挖填平衡以使总成本最低。在平原或草原地区,坡度与地表近似平行,介是高于地表足够的高度,以利于路面排水,苦有必要,可利用风力来清除表面积雪。如公路接近或沿河流走行,纵坡线的高度由预期洪水位来决定。无论在何种情况下,平缓连续的坡度线要比由短直线段连接短竖曲线构成的不断变向的坡度线好得多。

由上坡向下坡变化的路段应设在挖方路段,而由下坡向上坡变化的路段应设在填方路段,这样的线形设计较好,往往可以避免形成与现状地貌相反的圭堆或是凹地。与挖填方平衡相比,在确定纵坡线时,其他考虑则重要得多。

城市项目通常比农村项目要求对控制要素进行更详尽的研究,对高程进行更细致地调整。一般来说,设计与现有条件相符的坡度较好,这样可避免一些不必要的花费。

在坡度的分析和控制中,坡度对机动车运行费用的影响是最重要的考虑因素之一。坡度增大油耗显然增大,车速就要减慢。一个较为经济的方案则可使坡度减小而增加的年度成本与坡度不减而增加的车辆运行年度成本之间相平衡。这个问题的准确方法取决于对交通流量和交通类型的了解,这只有通过交通调查才能获知。

在不同的州,最大纵坡也相差悬殊,AASHTO标准建议由设计车速和地形来选择最大纵坡。现行设计以设计车速为70mile/h时最大纵坡为5%,设计车速30mile/h时,根据地形不同,最大纵坡一般为7%-12%。当采用较长的待续爬坡时,在没有为慢行车辆提供爬坡道时,坡长不能够超过临界坡长。临界坡长可从3%纵坡的1700英尺变化至8%纵坡的500英尺。

持续长坡的坡度必须小于公路任何一个断面的最大坡度,通常将长的持续单一纵坡断开,设计成底部为一陡坡,而接近坡顶则让坡度减小。同时还要避免由于断面倾斜而造成的视野受阻。调整公路的最大纵坡为9%只有当路面排水成问题时,如水必须排至边沟或排水沟,最小坡度标准才显示其重要性。这种情况下,AASHTO标准建议最小坡度为0.35%。

3、视距

为保证行车安全,公路设计必须使得驾驶员视线前方有足够的一段距离,使他们能够避让意外的障碍物,或者安全地超车。视距就是车辆驾驶员前方可见的公路长度。安全视距具有两方面含义:“停车视距”或“不超车视距”或“超车视距”。

有时,大件物体也许会掉到路上,会对撞上去的车辆造成严重的危害。同样,轿车或卡车也可能会被一溜车辆阻在车道上。无论是哪种情况发生,合理设计要求驾驶员在一段距离以外就能看见这种险情,并在撞上去之前把车刹住。此外,认为车辆通过离开所行驶的车道就可以躲避危险的想法是不安全的,因为这会导致车辆失控或与另一辆车相撞。

停车视距由两部分组成:第一部分是当驾驶员发现障碍物面作出制动之前驶过的一段距离,在这一察觉与反应阶段,车辆以其初始速度行驶;第二部分是驾驶员刹车后车辆所驶过的一段距离。第一部分停车视距取决于车速及驾驶员的察觉时间和制动时间。第二部分停车视距取决于车速、刹车、轮胎、路面的条件以及公路的线形的坡度。

在双车道公路上,每间隔一定距离,就应该提供超越慢行车辆的机会。否则,公路容量将降低,事故将增多,因为急燥的驾驶员在不能安全超车时冒着撞车危险强行超车,能被看清的允许安全超车的前方最小距离叫做超车视距。驾驶员在做出是否超车的决定时,必须将前方的能见距离与完成超车动作所需的距离对比考虑。影响他做出决定的因素是开车的小心程度和车辆加速性能。由于人与人的显著差别,主要是人的判断和动作而不是力学定理决定的超车行为随着驾驶员的不同而大不相同。

公路几何设计是确保公路交通安全的基础,公路建设的其他项目都围绕公路的几何设计而展开,因此,在公路的几何设计过程中,如果出现任意的不安全潜在因素,或者低水平的组合设计,都会影响到整个公路几何设计的质量,并对交通的安全带来不利影响。因此对于公路的几何设计必须予以重点关注。

桥梁工程毕业设计外文翻译箱梁

桥梁工程毕业设计外文翻译箱梁

西南交通大学本科毕业设计(论文) 外文资料翻译 年级: 学号: 姓名: 专业: 指导老师:

6 月

外文资料原文: 13 Box girders 13.1 General The box girder is the most ?exible bridge deck form. It can cover a range of spans from25 m up to the largest non-suspended concrete decks built, of the order of 300 m. Single box girders may also carry decks up to 30 m wide. For the longer span beams, beyond about 50 m, they are practically the only feasible deck section. For the shorter spans they are in competition with most of the other deck types discussed in this book. The advantages of the box form are principally its high structural ef?ciency (5.4), which minimises the prestress force required to resist a given bending moment, and its great torsional strength with the capacity this gives to re-centre eccentric live loads, minimising the prestress required to carry them.

道路规划外文文献1

道路设计 1.道路设计的历史 首先,本文主要依靠大量的文字叙述,若对您造成理解上的困难,敬请谅解。 由于本文所涵盖的资料单一,本文是此系列中唯一的一篇文章。本文不像其他文章 一样有大量图片说明。其次,本文主要内容是关于欧洲公路修筑的历史。 在西欧,罗马人是具有重大意义的公路修筑的开创者。他们看到了修筑公路能 使人较快的移动地理位置的作用,这一作用对军用和民用都是极其重要的。罗马人 率先指出,要使公路发展为主要道路,就必须把地坪线提高一米。公路的最大特点 就是没有角落,这是为了降低埋伏的风险。罗马人对道路的耐久性设定了标准,这 一成就远超过了罗马帝国灭亡后所取得的其它成就。 罗马人设计公路的方法本质上与现代使用的是相同。公路由几个不同层次构成,这从基层增加了公路的强度。最底层的通常是碎石子,中间层是掺加了石灰的混凝土,而上层则是铺路石或者掺有石灰的厚石板。每一层的厚度由当地的地质条件决定。 罗马帝国消亡后,它的道路系统一直处于无人修善的状态。到了中世纪末期, 全国的道路系统几乎处于瘫痪状态,唯一的路途就是没有铺石板的路。一到冬季就 泥泞不堪,夏天则尘土飞扬,根本无法通行。同时为了绕开贫穷的地区,更是导致 了道路弯弯曲曲,加大了通行难度。这种路况加上法律监管不严,意味着除非是疯 子或者是无可奈何的情况,没人愿意去走这些路。 这种情况直到1555年国会通过了所有地方政府有责任维修损坏道路的行动后有 所改善。这次行动还包括建立高速公路拯救员职位。没有薪金和材料再加上技术匮乏,所以这个告示明显地无人理睬且效率低下也就不怎么奇怪了。 …… 2.交通量分析 2.1、交通密度:

2.2、交通负荷: 3.交通密度 4.交通负载 5.土方工程 6.开挖 History of Road Design Firstly let me apologise for this page. It is largely text based due to the nature of it and if reading is difficult then I am sorry. This is due solely to the material covered and is the only page in the series. This is not typical as the rest have graphics or images to keep you amused. Secondly this page is very much a history of road building in the United Kingdom. The first road builders of any significance in Western Europe were the Romans, who saw the ability to move quickly as essential for both military and civil reasons. It is from the Romans that the term highway comes as all their roads were elevated 1m above the local level of the land. This was to minimise the risk of an ambush, as was the best known characteristic of the roads, their lack of corners. The standards set by the Romans in terms of durability far exceeded anything achieved after the fall of the empir e. The Roman approach to road design is essentially the same as that in current use. The roads were constructed of several different layers, increasing in strength from the bottom. The lowest layer was normally a rubble, intermediate layers were made of li me bound concrete and the upper layer was a flag or lime grouted stone slabs. The thickness of the layers was varied according to the local ground conditions. After the fall of the Roman Empire the road system fell into a state of disrepair and by the end of the middle ages, there was in effect no road

毕业设计外文翻译资料

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)

汽车专业毕业设计外文翻译

On the vehicle sideslip angle estimation through neural networks: Numerical and experimental results. S. Melzi,E. Sabbioni Mechanical Systems and Signal Processing 25 (2011):14~28 电脑估计车辆侧滑角的数值和实验结果 S.梅尔兹,E.赛博毕宁 机械系统和信号处理2011年第25期:14~28

摘要 将稳定控制系统应用于差动制动内/外轮胎是现在对客车车辆的标准(电子稳定系统ESP、直接偏航力矩控制DYC)。这些系统假设将两个偏航率(通常是衡量板)和侧滑角作为控制变量。不幸的是后者的具体数值只有通过非常昂贵却不适合用于普通车辆的设备才可以实现直接被测量,因此只能估计其数值。几个州的观察家最终将适应参数的参考车辆模型作为开发的目的。然而侧滑角的估计还是一个悬而未决的问题。为了避免有关参考模型参数识别/适应的问题,本文提出了分层神经网络方法估算侧滑角。横向加速度、偏航角速率、速度和引导角,都可以作为普通传感器的输入值。人脑中的神经网络的设计和定义的策略构成训练集通过数值模拟与七分布式光纤传感器的车辆模型都已经获得了。在各种路面上神经网络性能和稳定已经通过处理实验数据获得和相应的车辆和提到几个处理演习(一步引导、电源、双车道变化等)得以证实。结果通常显示估计和测量的侧滑角之间有良好的一致性。 1 介绍 稳定控制系统可以防止车辆的旋转和漂移。实际上,在轮胎和道路之间的物理极限的附着力下驾驶汽车是一个极其困难的任务。通常大部分司机不能处理这种情况和失去控制的车辆。最近,为了提高车辆安全,稳定控制系统(ESP[1,2]; DYC[3,4])介绍了通过将差动制动/驱动扭矩应用到内/外轮胎来试图控制偏航力矩的方法。 横摆力矩控制系统(DYC)是基于偏航角速率反馈进行控制的。在这种情况下,控制系统使车辆处于由司机转向输入和车辆速度控制的期望的偏航率[3,4]。然而为了确保稳定,防止特别是在低摩擦路面上的车辆侧滑角变得太大是必要的[1,2]。事实上由于非线性回旋力和轮胎滑移角之间的关系,转向角的变化几乎不改变偏航力矩。因此两个偏航率和侧滑角的实现需要一个有效的稳定控制系统[1,2]。不幸的是,能直接测量的侧滑角只能用特殊设备(光学传感器或GPS惯性传感器的组合),现在这种设备非常昂贵,不适合在普通汽车上实现。因此, 必须在实时测量的基础上进行侧滑角估计,具体是测量横向/纵向加速度、角速度、引导角度和车轮角速度来估计车辆速度。 在主要是基于状态观测器/卡尔曼滤波器(5、6)的文学资料里, 提出了几个侧滑角估计策略。因为国家观察员都基于一个参考车辆模型,他们只有准确已知模型参数的情况下,才可以提供一个令人满意的估计。根据这种观点,轮胎特性尤其关键取决于附着条件、温度、磨损等特点。 轮胎转弯刚度的提出就是为了克服这些困难,适应观察员能够提供一个同步估计的侧滑角和附着条件[7,8]。这种方法的弊端是一个更复杂的布局的估计量导致需要很高的计算工作量。 另一种方法可由代表神经网络由于其承受能力模型非线性系统,这样不需要一个参

桥梁专业外文翻译--欧洲桥梁研究

桥梁专业外文翻译--欧洲桥梁研究

附录 Bridge research in Europe A brief outline is given of the development of the European Union, together with the research platform in Europe. The special case of post-tensioned bridges in the UK is discussed. In order to illustrate the type of European research being undertaken, an example is given from the University of Edinburgh portfolio: relating to the identification of voids in post-tensioned concrete bridges using digital impulse radar. Introduction The challenge in any research arena is to harness the findings of different research groups to identify a coherent mass of data, which enables research and practice to be better focused. A particular challenge exists with respect to Europe where language barriers are inevitably very significant. The European Community was formed in the 1960s based upon a political will within continental Europe to avoid the European civil wars, which developed into World War 2 from 1939 to 1945. The strong political motivation formed the original community of which Britain was not a member. Many of the continental countries saw Britain’s interest as being purely economic. The 1970s saw Britain joining what was then the European Economic Community (EEC) and the 1990s has seen the widening of the community to a European Union, EU, with certain political goals together with the objective of a common European currency. Notwithstanding these financial and political developments, civil engineering and bridge engineering in particular have found great difficulty in forming any kind of common thread. Indeed the educational systems for University training are quite different between Britain and the European continental countries. The formation of the EU funding schemes —e.g. Socrates, Brite Euram and other programs have helped significantly. The Socrates scheme is based upon the exchange of students between Universities in different member states. The Brite Euram scheme has involved technical research grants given to

机械毕业设计英文外文翻译399驱动桥

附录A 英文文献 Drive Axle All vehicles have some type of drive axle/differential assembly incorporated into the driveline. Whether it is front, rear or four wheel drive, differentials are necessary for the smooth application of engine power to the road. Powerflow The drive axle must transmit power through a 90°angle. The flow of power in conventional front engine/rear wheel drive vehicles moves from the engine to the drive axle in approximately a straight line. However, at the drive axle, the power must be turned at right angles (from the line of the driveshaft) and directed to the drive wheels. This is accomplished by a pinion drive gear, which turns a circular ring gear. The ring gear is attached to a differential housing, containing a set of smaller gears that are splined to the inner end of each axle shaft. As the housing is rotated, the internal differential gears turn the axle shafts, which are also attached to the drive wheels. Rear-wheel drive Rear-wheel-drive vehicles are mostly trucks, very large sedans and many sports car and coupe models. The typical rear wheel drive vehicle uses a front mounted engine and transmission assemblies with a driveshaft coupling the transmission to the rear drive axle. Drive in through the layout of the bridge, the bridge drive shaft arranged vertically in the same vertical plane, and not the drive axle shaft, respectively, in their own sub-actuator with a direct connection, but the actuator is located at the front or the back of the adjacent shaft

道路与桥梁专业外文翻译中英对照

道路与桥梁专业外文翻译 中英对照 Jenny was compiled in January 2021

本科毕业设计(论文) 专业名称:土木工程专业(道路与桥 梁) 年级班级:道桥08-5班学生姓名: 指导教师: 二○一二年五月十八日 专业外文翻译

Geometric Design of Highways The road is one kind of linear construction used for travel. It is made of the roadbed, the road surface, the bridge, the culvert and the tunnel. In addition, it also has the crossing of lines, the protective project and the traffic engineering and the route facility. The roadbed is the base of road surface, road shoulder, side slope, side ditch foundations. It is stone material structure, which is designed according to route's plane position .The roadbed, as the base of travel, must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding. The road surface is the surface of road. It is single or complex structure built with mixture. The road surface require being smooth, having enough intensity, good stability and anti-slippery function. The quality of road surface directly affects the safe, comfort and the traffic. Highway geometry designs to consider Highway Horizontal Alignment, Vertical Alignment two kinds of linear and cross-sectional composition of coordination, but also pay attention to the smooth flow of the line of sight, etc. Determine the road geometry, consider the topography, surface features, rational use of land and environmental protection factors, to make full use of the highway geometric components of reasonable size and the linear combination. Design The alignment of a road is shown on the plane view and is a series of straight lines called tangents connected by circular. In modern practice it is common to interpose transition or spiral curves between tangents and circular curves.

毕业设计外文翻译附原文

外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华

外文资料名称: Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处:Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件: 1.外文资料翻译译文 2.外文原文

应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金,洪城铱昌,宰瑾李, 刘链柱译 摘要:旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率,压降,并切成尺寸被粒度对应于分级收集的50%的效率进行了研究。颗粒切成大小降低入口面积,体直径,减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法,用于收集在家庭中产生的粉尘。 摘要及关键词:吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子,工作场所,或其他建筑,因此,室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物,毒物,食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤,预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中,吸入压力下降说唱空转成比例地清洗的时间,以及纸过滤器也应定期更换,由于压力下降,气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形,在粗颗粒(>2.0微米)模式为主要的外部来源,如风吹尘,海盐喷雾,火山,从工厂直接排放和车辆废气排放,以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式,典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克,可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。

公路毕业设计文献综述

本科生毕业论文(设计)题目文献综述文献综述随着改革开放的深入,交通运输在生活中的作用越来越明显,高速公路的建设成为了国民建设中的一个重大问题。由于高速公路具有汽车专用,分隔行驶,全部立交,控制出入以及高标准,高要求,设备功能完善等功能,与一般公路相比具有很多优点,所以具有很强的实用性。目前,我国高等级公路建设正处在“质”与“量”并重的重要发展阶段。从大陆第一条高速公路——沪嘉高速开始,中国大陆高速公路建设进入了一个崭新的时期。高速公路在二十多年间展现出了巨大的优越性,在以建成的高速公路沿线及腹地迅速兴起了工业企业建设的热【1】潮,地价增值,地方税收增加,投资环境发生巨大变化。目前我国的高速公路主要分布在东南沿海,我国的沿海地带,大部分是淤泥质海岸。因此,沿海特别是大江大河河口附近多为河相、海相或泻湖相沉积层,在地质上属于第四纪全新纪Q4 土层,多属于【2】东南海岸土的类别多为淤泥,淤泥质亚黏饱和的正常压密黏土。土。这类地基的主要特点是:具有高含水量、大孔隙、低密度、低强度、高压缩性、低透水性、中等灵敏度等特点;具有一定的结构性。由于这类地基存在这些特点,在软粘土地基上建造建筑物普遍存在稳定及变形的问题。以高速为例,由于高速的路堤高度不大,所以稳定问题并不突出,但是变形问题很明显。目前高速桥头跳车以及高填方段、填挖结合部等位置因地基差异沉降对路面结构造成的不良影响已引起公路建设、设计、监理、施工等部门的日益重视。如何解决高等级公路桥头跳车问题已成为刻不容缓的大事。造成桥头跳车的原因【3】有很多:1、土质不良引起的地基沉陷:土质不良,由此产生沉陷是桥头跳车的主要原因。桥涵通常位于沟壑地方,地下水位较高,此类土天然含水量大于液限,天然孔隙比大,常含有机质,压缩性高,抗剪强度低,一旦受到扰动,天然结构易受破坏,强度便显著降低,桥头路基填筑高度较大,产生基底应力相对较大,在车辆荷载作用下,更容易引起地基沉陷,且变形稳定历时往往持续数年乃至更长的时间。既便是在一些稳定地基,在外荷作用下,也无可避免出现这个问题。2、台后填料的压缩沉降:台后填料一

本科毕业设计桥梁外文翻译

附录一:中文翻译 土木工程师 桥梁工程156 2003年3月发表于BEI 31~37页 2002年1月31日收到 C.詹姆斯 2002年12月9日通过高级土木工程师佩尔 Frischmann ,埃克塞特 关键词:桥梁;河堤;土工布;膜与土工格栅 英国锁城大桥 锁城大桥是横跨住宅发展区的铁路桥梁。由于工程施工受到周围建筑与地形的限制,该工程采取加固桥台、桥墩与桥面的刚构结构,以及预制栏杆等方法提高了大桥的使用安全程度,并降低了大桥建造与维护的费用。因此,城堡大桥科学的设计方案使工程成本降到最低。 一、引言 本文描述的是在受限制地区用最小的费用修建一座铁路桥梁使之成为开放的住宅发展区。锁城地区是位于住宅发展十分紧张的韦斯顿超 图1 锁城大桥位置远景

马雷的东部。监督桥梁建设的客户是城堡建设有限公司,它由二大房建者组成。该区的规划局是北盛捷区议会(NSDC)。该发展地区被分为布里斯托尔和埃克塞特。规划条件规定,直到建成这条横跨的铁路大桥为止,该地区南部区域不可能适应居住。可见锁城大桥的建成对该地区发展的重要性。 发展地区位于萨默塞特的边缘,这个地区地形十分的恶劣,该范围位于韦斯顿以北和A321飞机双程双线分隔线的南面。现在只有一条乡下公路,是南部区域的唯一通道。该地区是交通预期不适合住宅增加的区域。 由于盛捷地区水平高程的限制,新的铁路线在桥台两边必须设有高程差。并且该地区地形限制,允许正常横跨的区域较小,这导致在结构的布局上的一定数量的妥协。为了整个城堡地区的发展,全 图2 锁城大桥地图上位置 桥限速20公里/时,并考虑区域范围内的速度制约。这样在得到客户和NSDC的同意后,桥梁采取了最小半径的方法,这使得桥梁采用了比正常梯度更加陡峭地方法实现高程的跨越。 客户的工程师、工程顾问、一般设计原则和初步认同原则下(AIP)与NSDC发出投标文件。 该合同在2000年7月1授予安迪。投标价值1.31亿美元,合同期定为34周,到2001年4月完成。

道路设计外文翻译

道路设计外文翻译 摘要部分的翻译: 各种断面形状钢管混凝土的单轴应力应变关系 K.A.S. Susantha ,Hanbin Ge, Tsutomu Usami* 土木工程学院,名古屋大学, Chikusa-ku ,名古屋464-8603, 日本 收讫于2000年5月31日; 正式校定于2000年12月19日; 被认可于2001年2月14日 ?? 摘要 一种预测受三轴压应力混凝土的完全应力-应变曲线的方法被提出,这种三轴压应力是由环形、箱形和八角形的钢管混凝土中的限制作用导致的轴向荷载加测向压力所产生的。有效的经验公式被用来确定施加于环形钢管混凝土柱内混凝土的侧向压力。FEM(有限元)分析法和混凝土-钢箍交互作用模型已被用来估计施加于箱形和八角形柱的混凝土侧向压版权所有2001 Elsevier科学技术有限公司。 力。接着,进行了广泛的参数研究,旨在提出一个经验公式,确定不同的筒材料和结构特性下的最大平均侧向压力。如此计算出的侧向压力通过一个著名经验公式确定出侧向受限混凝土强度。对于高峰之后的应力-应变关系的确定,使用了有效的试验结果。基于这些测试结果,和近似表达式来推算下降段的斜度和各种断面形状的筒内侧向受限混凝土在确认的混凝土强度下的应变。推算出的混凝土强度和后峰值性能在允许的界限内与测试结果吻合得非常好。所提出的模型可用于包括梁柱构件在内的纤维分析,以确定抗震结构设计中混凝土填充钢柱筒的极限状态的推算标准。? 关键词: 钢管混凝土;限制;混凝土强度;延性;应力应变关系;纤维分析 Uniaxial stress–strain relationship of concrete confined by various shaped steel tubes K.A.S. Susantha, Hanbin Ge, Tsutomu Usami * Department of Civil Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan Received 31 May 2000; received in revised form 19 December 2000; accepted 14 February 2001 Abstract

毕业设计外文翻译

毕业设计(论文) 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年

研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院,中国南京,邮编210098 nzg_197901@https://www.sodocs.net/doc/4014630248.html,,niuzhiguo@https://www.sodocs.net/doc/4014630248.html, 李同春 河海大学水利水电工程学院,中国南京,邮编210098 ltchhu@https://www.sodocs.net/doc/4014630248.html, 摘要 由于钢弧形闸门的结构特征和弹力,调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中,简化空间框架作为分析模型,根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型,动态不稳定区域的弧形闸门可以通过有限元的方法,应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外,结合物理和数值模型,对识别新方法的参数共振钢弧形闸门提出了调查,本文不仅是重要的改进弧形闸门的参数振动的计算方法,但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力,没有门槽,好流型,和操作方便等优点,使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门,通过门叶和主大梁,所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂,手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中,除了极特殊的破坏情况下,弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外,明显的动态作用下发生破坏。例如:张山闸,位于中国的江苏省,包括36个弧形闸门。当一个弧形闸门打开放水时,门被破坏了,而其他弧形闸门则关闭,受到静态静水压力仍然是一样的,很明显,一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。

桥梁专业外文翻译--欧洲桥梁研究

中文1850字 附录 Bridge research in Europe A brief outline is given of the development of the European Union, together with the research platform in Europe. The special case of post-tensioned bridges in the UK is discussed. In order to illustrate the type of European research being undertaken, an example is given from the University of Edinburgh portfolio: relating to the identification of voids in post-tensioned concrete bridges using digital impulse radar. Introduction The challenge in any research arena is to harness the findings of different research groups to identify a coherent mass of data, which enables research and practice to be better focused. A particular challenge exists with respect to Europe where language barriers are inevitably very significant. The European Community was formed in the 1960s based upon a political will within continental Europe to avoid the European civil wars, which developed into World War 2 from 1939 to 1945. The strong political motivation formed the original community of which Britain was not a member. Many of the continental countries saw Britain’s interest as being purely economic. The 1970s saw Britain joining what was then the European Economic Community (EEC) and the 1990s has seen the widening of the community to a European Union, EU, with certain political goals together with the objective of a common European currency. Notwithstanding these financial and political developments, civil engineering and bridge engineering in particular have found great difficulty in forming any kind of common thread. Indeed the educational systems for University training are quite different between Britain and the European continental countries. The formation of the EU funding schemes —e.g. Socrates, Brite Euram and other programs have helped significantly. The Socrates scheme is based upon the exchange of students between Universities in different member states. The Brite Euram scheme has involved technical research grants given to consortia of academics and industrial

桥梁外文翻译

毕业设计/论文 外文文献翻译 院系城市建设学院 专业班级 姓名 原文出处 评分 指导教师 华中科技大学武昌分校 20 12 年3月1日

Study on nonlinear analysis of a redundant cable-stayed bridge 1.Abstract A comparison on nonlinear analysis of a highly redundant cable-stayed bridge is performed in the study. The initial shapes including geometry and prestress distribution of the bridge are determined by using a two-loop iteration method, it is an equilibrium iteration loop and a shape iteration loop. For the initial shape analysis a linear and a nonlinear computation procedure are set up. In the former all nonlinearities of cable-stayed bridges are disregarded, and the shape iteration is carried out without considering equilibrium. In the latter all nonlinearities of the bridges are taken into consideration and both the equilibrium and the shape iteration are carried out. Based on the convergent initial shapes determined by the different procedures, the natural frequencies and vibration modes are then examined in details. Numerical results show that a convergent initial shape can be found rapidly by the two-loop iteration method, a reasonable initial shape can be determined by using the linear computation procedure, and a lot of computation efforts can thus be saved. There are only small differences in geometry and prestress distribution between the results determined by linear and nonlinear computation procedures. However, for the analysis of natural frequency and vibration modes, significant differences in the fundamental frequencies and vibration modes will occur, and the nonlinearities of the cable-stayed bridge response appear only in the modes determined on basis of the initial shape found by the nonlinear computation. 2. Introduction Rapid progress in the analysis and construction of cable-stayed bridges has been made over the last three decades. The progress is mainly due to developments in the fields of computer technology, high strength steel cables, orthotropic steel decks and construction technology. Since the first modern cable-stayed bridge was built in Sweden in 1955, their popularity has rapidly been increasing all over the world. Because of its aesthetic appeal, economic grounds and ease of erection, the

相关主题