Vulnerability calculation method of prestressed concrete Tshaped girder exposed to vehiclesrelated fires(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2018年06期
- Page:
- 11-19
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Vulnerability calculation method of prestressed concrete Tshaped girder exposed to vehiclesrelated fires
- Author(s):
- ZHANG Xiaodong; MA Rujin; CHEN Airong
- （Department of Bridge Engineering, Tongji University, Shanghai 200092, China）
- Keywords:
- bridge engineering; fire; vulnerability; response surface; Monte Carlo; concrete Tshaped girder
- PACS:
- -
- DOI:
- -
- Abstract:
- To assess the fireresistance performance of prestressed concrete Tshaped girders exposed to fires caused by vehicles, the response surface method (RSM) was used to establish the response surface function instead of finite element analysis. Furthermore, the randomness of parameters was simulated by the Monte Carlo sampling (MCS), and the vulnerability analysis method based on RSMMCS was established. In this method, the damage level of bridge members was divided into four types: slight damage, moderate damage, extensive damage, and complete damage. The residual loading capacity was defined as the degree of damage of bridge members, and the partitioned criterion of damage status was specified on the basis of existing experiments and theoretical considerations. The problem of randomness in the parameters of fire hazard and structures was examined, and the central composite design method was used to generate test samples and verification samples. After the vulnerability analysis method based on RSMMCS was established, the vulnerability analysis of prestressed concrete Tshaped girder was performed. The results show that the vulnerability index based on the residual loading capacity of members can be applied to various failure modes. The partitioned criterion reflects the damage status of different bridge members. The randomness of fire hazard can be simulated by fire temperature, burning time, and distance between the fire and structures. The number of finite element calculations is significantly reduced because of the use of the central composite design method. Under consideration the uncertainties in the simulation of fire and structural response, the failure probability of different temperatures, and the different damage levels that can be estimated from the vulnerability curves. This study is very useful for risk assessment before fire hazards and provide reference of performance assessment after fire hazards.
Last Update: 2018-12-18