Safety evaluation of residual loadcapacity ofcolumn piers after fire exposure(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2021年2期
- Page:
- 55-65
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Safety evaluation of residual loadcapacity ofcolumn piers after fire exposure
- Author(s):
- SONG Chaojie; ZHANG Gang; WANG Fuqiang; WAN Hao; ZHANG Yongfei
- (School of Highway, Changan University, Xian 710064, Shaanxi, China)
- Keywords:
- bridge engineering; residual loadcarrying capacity; finite element analysis; column pier; fire scenario database; safety evaluation
- PACS:
- -
- DOI:
- -
- Abstract:
- To evaluate the safety performance and provide a theoretical basis for the maintenance and reinforcement of column piers after fire exposure, the residual loadcarrying capacity of column piers were analyzed, and its safety evaluation index was established after fire exposure. A column pier with height of 4 m and diameter of 1.2 m was selected as object. A fire scenario database was established, in which the maximum temperature, fire exposure position and fire exposure height of the pier were coupled. According to actual spalling characteristics of column piers after fire exposure, the three grade index of concrete spalling at high temperature was proposed. The loadaxial displacement curves of axially compressed column piers and the loadtransverse displacement curves of eccentrically compressed column piers under different fire scenarios were analyzed using finite element software ANSYS. Therefore, degradation of ultimate loadcarrying capacity of column piers was obtained, and the four grade damage index of column piers after fire exposure was established. The results show that the residual loadcarrying capacity of column piers decreases with increase of the maximum temperature. The residual loadcarrying capacity of column piers with half sides exposed to fire is significantly lower than that of column piers with all sides exposed to fire. The residual loadcarrying capacity of column piers with half height exposed to fire is significantly lower than that of column piers with full height exposed to fire. The ultimate loadcarrying capacity of eccentrically compressed column piers declines faster than that of axially compressed column piers after experiencing same fire scenario, and the damage grade of eccentrically compressed column piers is higher than that of axially compressed column piers. The eccentrically compressed column piers with all sides and full height exposed to fire reaches grade Ⅳ damage when the maximum temperature reaches 600 ℃, while the axially compressed column piers after exposed to same fire scenario is grade Ⅱ damage. 2 tabs, 8 figs, 27 refs.
Last Update: 2021-04-02