Study On The Effects Of Temperature Field In Construction And Finished State Of PC Cable-stayed Bridge’s Components

Accompanying with the development of large span cable-stayed bridges, the importance of the temperature on its construction process and bridge operation state is gradually increasing. The control of construction occupies a pivotal position in cantilever-construction, temperature is one of the main influencing factors that affects the construction progress, leads to delay, and also is an important factor in construction control precision. Among the active cable-stayed bridges, the bearing manufacturing and unreasonable using that leads to the destruction of the bearing to happen sometimes. The influence of temperature is also very important, especially the stack with other factors can result in bearing force unreasonably. As time passes, they damage.Temperature on the influence of different time states of cable-stayed bridges are different, the temperature effect is larger for the measurement of elevation/cable force/tower deviation, and the model, tensioning cable force, if do not consider the effect of impact factors, it is hard to effectively comparison the data of the actual state and the ideal state. According to a central space radiation cable-plane concrete cable-stayed bridge project which is under construction in Guangdong province. By setting the temperature sensor, and applying the large finite element bridge software Midas/Civil to establish the whole bridge and analysis the structure. Simulating the temperature stages of the main girder, the tower and the cable to analysis each indexes of the construction stages and post stage. This paper had carried out the following research contents:1. By setting the temperature sensor to get the data of each component, analyzing the distribution of temperature of the girder, the tower and the cable throughout day and night. By means of fitting the data we get the most unfavorable temperature distribution which is suitable for similar bridges in Guangdong province, deducing the vertical temperature gradient of the girder、the difference of the temperature between cable and tower、 the temperature gradient of the tower and the temperature of the whole structure up and down.2. Through calculating the influence of the beams that have constructed/the cables that have tensed and tower deviation under different temperature distributions, stating that the influence of the temperature cannot ignore. Based on the detailed analysis of the states of the short/medium/long double-cantilever, correcting the temperature that influencing the elevation/tension and tower deviation, especially in the tense process of construction. That proves the availability of the data. At the same time, analyzing the effect of different construction phase under the temperature difference between each component of the bridge, in order to provide theoretical supporting to determine scientific and reasonable the elevation of the girder and the tension force of the cable. Reducing the temperature influence on it as far as possible in case that driving the time limit for a project.3. The analysis of the temperature effects the phase that before the bridge closed is a scientific basis for selecting the temperature for the bridge closed. It provides a good support for the bridge closed safely/the linear of the completed bridge smooth/the internal force reasonable forever.4. The analysis of the cable force/the linear/tower deviation of the completed bridge under each temperature distributions, providing design institute effective reference for ensure the reasonable state of the completed bridge of the same type of concrete cable bridges.5. The analysis of reaction and displacement of each bearings locating the tower/auxiliary pier/transitional pier of the completed bridge under each temperature distributions, providing the value of reference and the significance of guiding for designing the bearings of the same type of concrete cable bridges in Guangdong province.