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.

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 dir ection, 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