权威trados英汉记忆库：土木工程(3万字)

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概论General Considerations 1. 交叉口间距 1. Intersection Spacing

公路设施的整体安全和运行能力很大程度上受交叉口的影响。尽管总的交通流量是不变的（假设交叉口类型不变），但很显然，潜在交通冲突点的总数量与交叉口的数量和间距（公路入口密度）有直接关系。高速公路的入口数量和交通设施的类型就通常会有所限制，以确保高速公路有较高的安全性并充分利用交通设施。通常设计者应该限制各种类型公路入口数量，并以此作为好的设计的衡量指标。因为，交通回流对司机来说是个固有的危险，当发生撞车时容易引起死伤。The overall safety and capacity of a highway facility is largely affected by the presence of intersections. Obviously the total number of potential conflict points is directly related to the number of intersections or spacing of intersections along the highway(density of access point) although the total conflicting volumes remain the same(assuming the types of intersections do not change). Generally the number of access points allowed on freeway and expressway types of facilities is limited to ensure a high degree of safety and to optimize the capacity for the facility.Generally a designer should attempt to limit the number of access points for al roadway classifications as a measure of good engineering design practice.

2. 设计控制 2. Design Controls

相交公路的类型影响交叉口设计的诸多方面。交叉口设计及交通控制类型必须与香蕉道路的设计、使用、通行及功能相一致。驾驶者的期望一定是反映了这个道路交叉口是否重要。例如，在高速公路上行驶，除非到了出高速公路时，否则司机都不希望碰到平交口。可以采用恰当的交通控制来实现通过交叉口的车辆行驶道路正确。通常采用禁行标志来保证某条相交路的最小交通流量或者保证这条路的交通分级。The types of intersecting govern many aspects of intersection design. The intersection design and type of control must be compatible with the design,operational,traffic,and functional characteristics of the intersecting roadways.The expectations of drivers must reflect the importance of the connecting roadways.For example a driver who is travelling along a freeway type of facility does not expect to encounter an at-grade intersection unless the freeway facility is ending.At highway-intersections appropriate control devices are used to designate right of way. Normally the legs which carry the lowest traffic volumes or classification are controlled by stop

现在和未来的交通流量和特性在高速公路的规划和设计阶段就必须考虑到。交叉口行车道的数目，是否需要转向车道，以及交通控制的类型都取决于交通特性。设计时，考虑通行车辆要以交通组成为基础。Present and future traffic volumes and characteristics must be considered in planning and design of intersections.The number of approach lanes,the need for turning lanes and the type of traffic control depends upon the traffic characteristics.The selection of the appropriate design vehicle is largely

设计驶入速度将影响渠化交通、转向车道、渐变段长度和交通控制类型的设计。The design speed for the approaching highways will influence the design of channelization,turn lane and taper lengths and the type of traffic control.

服务水平和交叉口汇流能力分析是交叉口几何形状设计的基本部分。一个好的做法是，发现有潜在通行能力问题的交叉口应进行检查。The level of service and intersection capacity analysis are an essential part of geometric design.It is considered good engineering practice to check any intersections that are perceived as having potential capacity

3. 交叉口类型 3. Intersection Types

常见的平交口几何形状有三条道路汇交的T形或Y形交叉，以及四条道路汇交的十字形交叉。此外还可能遇到多岔交叉的转盘式交叉口。交叉口的类型和使用的交通控制类型合起来决定了潜在冲突点的数量。有五条或者五条以上道路汇交的交叉口通常不够安全，效率低，且会使驾驶者不知所措。图5-2所示为目前的平交口类型。The common geometric forms for intersections are three-leg(T or Y)or four leg intersections(cross roads). Other types which may be encountered are multi-leg rotary intersections.The type of intersection combined with the type of traffic control used at the intersection governs the number of potential conflict points.Intersection with five legs or more are generally unsafe, inefficient and confusing to the driver. Figure 5-2 shows types of

四条道路汇交的交叉口在省道上应用最多，它在次要道路上设有禁止通行控制。这种类型的交叉口存在32个潜在的冲突点，而这些冲突点将置通过交叉口的司机于某种危险的境地。用来估算潜在冲突点的最常用方法是概率论，也就是预计冲突发生的几率的方法。The most common intersection encountered on the Provincial Highway System is a four-leg intersection which employs stop control on the minor roadway.At this type of intersection32possible conflicts points exist which places the drivers at some level of risk when travelling through intersection.The most common methods used to estimate the potential for conflict is to use probability theory.In other words, the probability of an

4. 准线 4. Alignments

交叉口通常设在切线段上，因为当交叉口位于水平曲线上或其附近时，容易发生严重的操作问题。Intersections are generally designed on tangent sections because serious operational problems may occur when an intersection is located on or in the vicinity of a horizontal curve.

基础的选择Choice of Foundation

基础的类型主要取决于持力层的深度和它的安全承载能力，同时也受到不同类型桥面板差异沉降的限制。通常，简支桥面板的差异允许值大约在20～25mm之间，然而多跨连续桥面板通常10mm的差异沉降就认为是极限了。Foundation types depend primarily on the depth and safe bearing capacity of the bearing stratum,also restrictions placed on differential settlement due to the type of bridge deck.Generally in the case of simply supported bridge decks differential settlements of about 20and25mm can be tolerated, whereas multi-span continuous decks 10 mm is usually considered as a