Abstract:The leaning-pylon cable-stayed bridge is often applied in the municipal bridges because of its beautiful design, excellent visual effect and other characteristics. Taking the steel structural leaning-pylon cable-stayed bridge spanning Jiangxi River in North Line I Road Project in the north of Chengdu Tianfu International Airport New Town as the engineering background, this bridge has the characteristics of wide bridge deck, single back cable and special spatial-shaped pylon. Based on this, convenient for the pedestrian and vehicle traffic, and the structural layout, the super-wide gradual-change deck is used. Affected by the super-wide gradual-change deck, all cross beams are designed on the unequal length. One back cable is erected at the single side of the pylon. The anchorage is scattered at the top of the pylon and at the anchor under the back cable. The pylon is a spatial special-shaped structure. The pylon adopts octagonal section form. A groove shape is set towards one face of the main span. The transverse overall is inward tilt 12°, and the irregular arc is along the bridge. In order to improve the stress of the pylon, four pylon collar beams are erected at the node of the pylon top. In view of the stress complexity of the bridge structure, the geometric nonlinearity is considered. Based on the finite element software, a 3D spatial finite element model is established to analyze the structural mechanics under the most unfavorable load. The analysis shows that the strength, rigidity and cable fatigue of the bridge all meet the requirements. And the most unfavorable point of the stress is located at the anchorage of the back cable beam end. It is suggested to strengthen the optimization design of this place.
