The main bridge of Hongqili Rail-cum-Road Bridge carrying a section of the Shenzhen-Jiangmen Railway is a cable-stayed bridge with a main span of 808 m,crossing the navigation channel with no support of river piers.The superstructure,accommodating 8 lanes of freeway on the upper deck and 4 track lines on the lower deck,is of an inverse-trapezoidal cross-section,with two planes of vertical steel trusses,which reveals a balance between the structural configuration and economic performance.The steel boxes connecting the two planes of steel trusses form the two levels of decks of the central span and act compositely with the steel trusses.The superstructure in the three spans of 100 m on each side of the main span consists of two planes of steel trusses and the connection concrete panels acting compositely with the rectangular steel tubes of the trusses that are filled with concrete,the concrete-filled steel tubes are on the one hand engaged in load bearing performance of the bridge,and on the other hand support cable-girder anchorages and serve as counterweights as well.The connection concrete panels involve 32 cm-thick precast concrete slabs and 40 cm-thick cast-in-place layers.The steel-concrete joint section features the latticed chamber and bearing plates,with the steel-concrete interface located in the center span,4.6 m to the pylon.The pylons are H-shaped concrete pylons,each supported by 35 bored piles of 4.0 m diameter.The stay cables are composed of parallel steel wires with a nominal tensile strength of 2 000 MPa,with the highest grade of PES(C)7-547.To create reliable load transfer path and improve the fatigue strength of the bridge,the steel anchor boxes in the superstructure were encircled by the node of the chords of the secondary trusses.The large stay cables are anchored to the pylons by the combined self-balancing and cross-over technique.The steel trusses were divided into segments in the longitudinal direction and zones in the transverse direction to facilitate fabrication and transportation,and assembled at the bridge site.
cable-stayed bridge/rail-cum-road bridge/a system of very short side span and multiple auxiliary piers/inverse-trapezoidal cross-section of two planes of trusses/hybrid girder/steel-concrete composite girder/self-balancing cross-over anchor/bridge design
维普
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