The Study Of Construction Control Of Si Fangtai Cable-stayed Bridge

As a kind of flexible structure with great ability of span,cable-stayed bridge has great progress in recent years. But because of an indeterminate flexible structure with many degree of redundancy, The construction ways and fixing program is extremely relateted to the line form of the succeeded bridge girder and the dead load internal force of structure. In the contraction stage, following the structure system of the cable-stayed bridge and load postuarl, the internal force and distortion of structure chang unceasingly too. so, for doing a specific ordainment to the construction order,and actualize effectively control in the construction.we must carry through analysis and calculate at large to every construction stage of the cable-stayed bridge,and gained the theory value parameters of the construction control of the drawing tonnage of the cable , the deflection of the main girder and the displacement of the tower pole.On the another hand,because it is affected randomly by various factors(such as modulus of elasticity, shrink and creep coefficient , structure deadweight , construction deadweight , temperature influence and so on) ,and it will bring forth error in the way of measure,Ihe intrinsic throry design value of the structure can't be consistent with the practice value,it will exist warp between they,especially,some warp(such as elevation error of the main girder , axes error, cable force error and so on) have cumulate characteristics.so if we don't adjust the warp in time, the elevation of the main girder will deflect the design value following the cantilever length increasing of the main girder,it will make the fold become difficult and affect the internal force and distortion of the builded bridge.especially for the long-span bridge,if we can't identify and deal with the irrational error in the construction,the stress of the main girder and cable tower may bring birth accumulation,then overtop the safety state of design.Based on the HaerBin-Si Fangtai cable-stayed bridge,This paper studied the construction control of long span bridge.analysed the basis theory, the system of constructin control and the main effect factors, and carried though the emulational calculation of the cable-stayed bridge's construction stages.Then forcasted the fixing elevations of the cable-staged bridge by using the Kalman way and by using the Least Squares Method, and worked out the error analysis program of cable-stayed bridge.It make the forcast results veracity come true. ultimately,formed the integrated construction control system of cable-staged bridge. And validated the veracity of the program by using examples.