Construction Control Of Long-span PC Cable-stayed Bridge And Temperature Effect Analysis

Because of the complicated construction procedure of the long-span cable-sayed bridge, it will be affected by many certain or uncertain parameters,the actual construction state of the bridge might deviate from the state of the oretical design. The bridge construction control emphasizes the problem-finding out and error-adjusting in time, and state-predicting for following construction, so as to guarantee the construction system under control all the time. This paper took a certain bridge construction project of Changshou Yangtze River Cable-Stayed Bridge as the example to study bridge construction control and temperature effect of long span cable-stayed bridge.This paper introduces briefly the construction control technologies and methods for long-span cable-stayed bridge.construction control model has been established with Dr. bridge of plane finite element software,analyse the effect on the beam stress,elevation and cable tension which are caused by some important factors such as beam deadweight and creep of the concrete and so on,and make sure how to control these important factors during the construction.This paper explain the Gray Predictive System including its basic theory,technique, application step and the practical application. The mainly state variables which affect the system's behavior can be predicted through the establishmen of gray predictive model. It is shown that model GM(1,1) can predict many random variables such as the cable tension and beam's deflection when concrete is casted during the construction process of cable-stayed bridge, and this system can simultaneously achieve the objective of"double control"on both the bridge's elevation and cable tension, so that the constructing state is in coincidence with the designing state.The space model is established by MIDAS/Civil and it is used to respectively analyse influence of structure line shape, intenal forces and the cable tension caused by system temperature variation, temperature variation between cables and beams,the temperature gradient of girder and tower temperature gradient of the cable-stayed bridge at the state's largest cantilever. The discipline has been found through its comparative analysis, put forward the problem that should be pay attention to during the actual construction control process.