Kap Shui Mun Bridge 2.94

The Kap Shui Mun Bridge in Hong Kong is one of the longest cable-stayed bridges in the world that transports both road and railway traffic, with the upper deck used for motor vehicles and the lower deck used for both vehicles and the MTR. It has a main span of 430m and an overall length of 750m. It spans the Kap Shui Mun marine channel between Ma Wan and Lantau and has a vertical clearance of 47m above sea level. The bridge was completed in 1997.Structural informationThe total length of the Kap Shui Mun Bridge includes a 70m approach span on the Lantau side. There is a column in each of the back spans of the cable stayed bridge, making four 80m spans, adding to the 430m main span. This makes the total length 820m. The 503m Ma Wan Viaduct was constructed under the same contract as the KSMB. The viaduct connects the KSMB to the Tsing Ma Bridge, forming the Lantau Link, which was built to provide access to the new airport. The navigation clearance of 47m is part of the reason that the H-shaped towers are 150m tall.The Kap Shui Mun Bridge is not symmetrical, in that the 160m back span length (two 80m spans) is less than half of the main span length (which would be 215m). To provide the balance that symmetry will normally provide, part of the bridge has a composite structure. The center 387m of the main span uses a steel-concrete composite to make the structure lighter. The back spans and the rest of the main span are concrete. Using the lighter steel cross section in the majority of the main span serves to equalize the horizontal forces on the towers and balance the bridge.