Research Of The Force Characteristics And The Construction Control Of Double Main Ribbed Cable-stayed Bridge

As a delegate of concentrated system cable-stayed bridge, the double main ribbedcable-stayed bridge has better force characteristics, lower price and more convenience inconstruction, so it is becoming an important direction in the development of long spanconcrete cable-stayed bridge.Construction control is necessary for the construction of double main ribbed cable-stayedbridge. Under the project background of Da Nansha bridge, the practical problems whichexist in the structure analysis calculation before construction control and the procedure ofconstruction control are researched in this paper. The research includes the followingrespects:（1）As there is a space between two ribs of double main ribbed girder structure, thebridge roof will engender shearing deformation and transversal stress will distributeasymmetrically when girder is under load. This paper research the shear lag effect during theconstruction of double main ribbed cable-stayed bridge. The result states that axial force is themain effect of shear lag effect when double main ribbed girder is under compression-bendloads, so primary beam theory can be used in structure analysis calculation of double mainribbed cable-stayed bridge.（2）Via setting camber during the construction, the finished shape will be controlled. Atthe same time, a parameters identification sensitivity analysis of finished shape is necessary tomake. The camber is divided into construction camber and finished camber, so constructioncamber further breaks up into calculation camber and deformation camber. The paper willanalyze the solving method of every camber and distribute them optimally in practical projectsituation. When ensuring the length of the cable, we must consider the effect of the camberwhich we made before.（3）Cantalever pouring construction is widely used in the construction of the cablebridge. During the construction, the deformation of hanging basket is very important inensuring the finished shape. But, few literature can be found. So the paper will state theexactly method of making the formwork elevation via considering the relationship betweenthe fulcrum of hanging basket and elongation of the cable. If the method above is done verywell during the construction, we can make sure that the girder and hanging basket will be safeall the time.