Effect of temperature on main beam elevation in construction control of concrete cable-stayed bridge(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年06期
- Page:
- 63-69
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Effect of temperature on main beam elevation in construction control of concrete cable-stayed bridge
- Author(s):
- LIU Guo-kun; YAN Dong-huang; TU Guang-ya
- School of Civil Engineering, Changsha University of Science & Technology, Changsha 410114, Hunan, China
- Keywords:
- bridge engineering; concrete cable-stayed bridge; numerical analysis; temperature; construction control; main beam elevation
- PACS:
- U446.2
- DOI:
- -
- Abstract:
- In order to study the influences of temperature on main beam elevation, a numerical analysis method based on measured temperature field was adopted in this paper to study the sensitivity of relative parameters on main beam elevation, such as axial strain and curvature of cables, towers and girders. Moreover, temperature effect on main beam elevation was analyzed under main weather conditions (continuous sunny days, rainy days, large temperature differences between day and night and seasonal change). The results show that the numerical analysis method based on measured temperature field can quickly and accurately calculate the influence of temperature field on main beam elevation. Due to the containment effect of stay cables, the temperature curvature changes of main beam have low influence on its elevation. When the temperature difference is very small during the wee hours, the influence of curvature of main towers and beam on main beam elevation is also small for concrete cable-stayed bridges. The axial strain affected by temperature of stay cables, main towers and main beam has significant influence on main beam elevation. Temperature of measuring point in the middle wall of main towers can be roughly regarded as the average temperature of the whole section to calculate the axial strain of main tower. Considering only the influence of axial temperature strain of cable, tower and beam on main beam elevation is close to the total temperature effect, which can be used to quickly evaluate the temperature effect on main beam elevation. On continuous sunny or rainy days in summer and continuous sunny days with large temperature differences between day and night in autumn, it is effective to avoid the temperature influence because of uniform temperature filed before sunrise. Main beam elevation is slightly high due to low cable temperature at this time, and goes down quickly with cable temperature growing rapidly after sunrise. Within 1 to 2 h after sunrise, as the sunshine intensity is not strong, the decreasing amplitude of elevation is limited and closer to the ideal state. At this time, the temperature filed is convenient for construction control. When summer turns into autumn, temperature drops sharply at wee hours and the temperature filed, which has a worse influence on construction control than usual and can hardly be avoided, becomes complicated.
Last Update: 2017-12-18