Design of Steel Girder of Main Bridge of Huanggang Changjiang River Rail-cum-Road Bridge

The main bridge of Huanggang Changjiang River Rail-cum-Road Bridge is a fivespan continuous steel truss girder cable-stayed bridge with span arrangement(81+243+567+243+81)m.The bridge is designed as the one of the structural system of rigidly fixed pylons and piers and separated pylons and girder and is arranged into the double-deck steel truss girder structure.The upper deck of the bridge carries bidirectional 4-lane expressways and the truss width of the deck is 27.5mwhile the lower deck carries double-track railways and the truss width of the deck is 16m.The cross section of the steel truss girder is the inverted trapezoidal inclined main truss section having the truss height of 15.5mand panel length of 13.5m.The main truss is the N-shape truss,the upper and lower chords of the truss are of the parallelogram sections and the diagonal members are of the parallelogram or the inclined I-shape sections.The panel points are the welded integral panel points and the members at the locations of the points are all spliced with equal strength.The stay cables are anchored in the panel points of the upper chords via the builtin steel anchor boxes.The floor systems of the roadway and railway are the integral orthotropic floor systems of plate and truss composite structures and at the locations of the panel points of plate the upper chords,the lateral bracing systems of triangular trusses are arranged.