Structural Design of Main Bridge of Fenfangwan Changjiang River Bridge

The main bridge of Fenfangwan Changjiang River Bridge in Jiangjin,Chongqing is a light rail-cum-road semi-floating system steel truss girder cable-stayed bridge with double pylons,double cable planes and with span arrangement(60.5+156+464+156+60.5) m.The pylons of the bridge are the pagoda-shape curved partial prestressed concrete structures.The total height of the columns of a pylon is 188.30 m and in between the pylon columns,three cross beams are arranged.The foundation of the pylon is formed by the large diameter(3.0 m) bored piles plus reinforced concrete pile cap.The steel truss girder employs the spatial triangular truss topped with orthotropic deck plates.On the upper deck of the truss girder,the dual three-lane roadway is arranged while on the lower deck,the double-track light rail transit is laid.At each point of the stay cables,a pair of two cables is used to replace a single cable as is the normal case of cable-stayed bridges so as to reduce the influences of the concentrated stress from the strong cable forces on the pylon columns,which at the same time makes it feasible for future replacement of the stay cables without interruption of the light rail traffic.