Construction Control Analysis Of Long-span Cable-stayed Steel Truss Bridge

The unique truss structure of cable-stayed steel truss bridge let it has some characteristicsof strong bearing，higher integral rigidity，large in span etc. Along with the rapid developmentof high-speed railway construction in our country，cable-stayed steel truss bridge more andmore become the future development of bridge. This paper based on Si Xian Jiao long-spancable-stayed steel truss bridge analyses several key factors of its construction control：（1）Alignment trend of cable-stayed steel truss bridge during its construction is directlyrelated to the closure of steel truss girder and obtainment of the final design of the bridgealignment. This paper introduces the analysis and calculation of manufacture line andinstallation line of cable-stayed steel truss bridge and analyses the internal relation betweenthem. Cable-stayed steel truss bridge obtains camber by changing the chord member usually.This paper introduces several methods of the calculation of the change of the chord member.（2）The closure of cable-stayed steel truss bridge has several characteristics，such asmany closure points，high closure precision，adjustment hard. So it is important to analyze itsclosure state. This paper introduces the only state of the closure of cable-stayed steel trussbridge and the calculation of it.（3）Not vertical stayed-cable could generate sag effect under gravity，which lettheoretical cable force produce deviation compared to actual cable force. This paper introduceshow to rectify the deviation. It is needed to adjust cable force temporarily to obtain specificinstalling line during the construction of cable-stayed steel truss bridge recovered after theclosure of full bridge，and the difference of construction method also cause the change of cableforce，both introduced in this paper.