Analysis Of The Temperature Of The Tower And Study On Temperature Change Characteristics Of The Tower Cracks Of Cable-stayed Bridge

Cracks in concrete tower are one of the common diseases, people have concerned on the quality problems caused by cracks. Therefore it is significance for propose to viable treatment options through knowing the cause to the cracks and understanding the change and development of cracks. The appearance of cracks, on the one hand, has impact on the strength and durability of the structure, reduce the strength and durability of the structure; On the other hand, appearance of cracks is possible to release the structures stress. For the cracks of concrete boxes such as bridge tower and concrete box girder, because of the reasons for the temperature difference between inside and outside walls, the crack width will appear the "temperature variability" movement due to temperature changes. Understanding the cracks' "temperature variability" phenomenon is significant, to understand the emergence and expansion of cracks about cylinder-shaped structure and ensure bridge construction quality and the safety of bridge-building.Through observing the tower cracks of a cable-stayed bridge for a long time, we find that cracks don't constantly maintain open and the crack width changes with the different temperature between the tower inside and outside, which is called the temperature variability phenomenon of cracks. At the context of the tower cracks of the cable-stayed bridges.This paper discusses the concrete structure about temperature stress of caloric load and research at home and abroad and studies the theoretical temperature loads and the theory about temperature thermal stress analysis of the fracture mechanics.Secondly, according to the tower bridge temperature and continuous observation tower cracks in the summary data, get crack width and temperature changes in the symmetry relations. Using large software simulate the force in the whole state of the bridge, We can get the calculated results of the cable and get the stress values of the tower's section. We can intercept the tower's interception near the cracks in the typical anchor head and use the software to simulate the stress then we can get the stress values of the tower's section. Using software to calculate the sunshine transient temperature distributions and thermal stress on different temperature between two different role. Then add up the towers section's stress. Finally, we can simulate the cracks under the impact of the temperature field, analyses the cracks tip's stress and then test the crack's temperature changeable characteristic. For the closed and expansion phenomenon of the concrete cracks, we can cite the cracks closed theory of metal parts and adopt the concept of the valid stress, then can sufficiently explain this phenomenon of the concept cracks.