1、附录 4 外文文献翻译 RAILWAY SUSPENSION BRIDGE IN WOERDEN, THE NETHERLANDS SUMMARY In Woerden, a small town in the west of the Netherlands, a railway fly-over has been builtwhere two railway tracks meet. The fly-over consists of a single-track viaduct. This has alength of 438.5 m. The crossing angle is 10 de
2、grees. At the fly-over site the viaduct is suspended from a pylon that has been constructed over two tracks passing underneath. 1. INTRODUCTION A railway bridge was constructed in Woerden as part of the track expansion of theNetherlands Railways. More trains will be run, the running speeds will be i
3、ncreased and thepossibility of delays must be reduced. In order to make this possible, many line sections mustbe four-track and trains must be able to cross each other at different levels. This paper examines the fly-over in Woerden. 2. SITUATION AND REQUIREMENTS The fly-over in Woerden must bridge
4、the following elements: - two existing tracks； - two future tracks； - a polder drainage pool； - an underpass for all traffic. The subsoil exhibits a great variation in compressibility. The forecast for settlement after 30years for the adjacent track bed on one side is about 0.5 m and on the other si
5、de about 3 m. To limit settlement, and due to the lack of space for access, the construction height of thebridge must be as low as possible. The existing tracks and the underpass must remain in operation during the construction. Theflow capacity of the polder drainage pool may not be restricted. 3.
6、GENERAL DESCRIPTION The total length of the viaduct is 438.5 m, comprising six sections (fig. 1). Section I crosses the underpass and has a length of 82.3 m. The two intermediate supports aresituated immediately adjacent to the concrete casing of the underpass, setting the spans at 22.7 m, 35 m and
7、22.65 m. Sections II to V have a length of 47.3 m and each consists of two spans of 22.65 m. Thelengths and spans were determined by the remaining space between sections I and VI and costoptimisation. Section II crosses the polder drainage pool. Section VI, with a length of 167 m, crosses the two ex
8、isting and the two future tracks. Thespans range between 26.3 and 46.7 m, with the supports staggered under the side beams. Allbridges have been made from pre-stressed concrete. To limit the construction height, it was decided to employ a U-shaped cross-section (fig. 2). The track floor lies low bet
9、ween the two load-bearing perimeter beams with a breadth of 1.4m. The height of the beams is 1.5 m for the small spans and 2.8 m for the larger. Theappearance of a gradual transition from low to high beams is caused by walls that increase inheight at the ends of the low beams, connecting to the high
10、 beams. The track construction consists of a continuous ballast bed. Only for the transition fromsection VI to the track bed are two compensation welds used in the rails to absorb changes inlength due to temperature shifts. At the other joins between the bridge sections the rails run continuously th
11、rough. The lack of space at the site means that the crossing angle with the tracks that are to be newlylaid is only 10 degrees. In addition, points are projected to be positioned in the tracks passing underneath, so that no columns can be located between the new tracks. For such situations, pergola
12、constructions are often built, consisting of long rows of columns along the trackwhich support a concrete deck with a span direction perpendicular to the tracks passingunderneath. The pergola would in this situation be 160 m long and vary between 14 m and 28m in width. For aesthetic and economic rea
13、sons, an innovative solution has been developed: Thesuspension of the crossing U-shaped bridge from a pylon which is constructed over the tracksthat will be running underneath (fig. 3). This creates a transparent construction thatguarantees a view of the countryside and clearly expresses the forces at work. This bridge isthe first of its kind in the Netherlands.
