Study On Vulnerability Of Old Reinforced Concrete Structures In Fires

Reinforced concrete frame structures are the main building structure forms in our country. At present, there are a large number of reinforced concrete buildings, and the occurrence times of fire are also more. Fire could cause large property losses and casualties every year, therefore, how to evaluate building vulnerability under fire quickly and reasonable, for the detection and reinforcement of the construction and reform, is great important. This paper is based on the research of the old reinforced concrete frame structures. Through summarizing the fire risk assessment and building vulnerability research method s under earthquake, according to the building characteristics under fire and the construction features o f high temperature before and after, research method is given, and the analysis model is built. This article is mainly focusing on the following parts:1. A comprehensive evaluation model of the vulnerability of the old reinforced concrete frame structures was built under fires. By analyzing the spreading process of building fire and the mechanical properties of structural components at high temperature, the indexes of the evaluation model were determined, and these vulnerability factors were analyzed. Through analyzing the advantages and disadvantages of all kinds of comprehensive evaluation methods, and a lot of fuzzy data existed, the fuzzy comprehensive evaluation method was applied to build the model finally. According to the theory of fuzzy comprehensive evaluation method, the membership function of the factor is determined, and then the weight coefficient of the model is determined by analytic hierarchy process for peer evaluation index model, and the fuzzy comprehensive evaluation of multiple evaluation system is established.2. The FI-VULNER for evaluating the vulnerability of the old reinforced concrete frame structures was wrote under fire s. Based on the Visual Basic 6.0 programming software, the “vulnerability assessment system” software was developed, which can be used to evaluate the vulnerability hierarchies quickly and reasonably, and the operation methods and processes of the evaluation software are given.3. The vulnerability assessment system was used in the engineering example. Using the assessment system to analyze the engineering example with the FI-VULNER, the vulnerability of YanDu hotel was evaluated in Chaoyang. By considering the different fire scenarios, it give n the corresponding vulnerability assessment result of old buildings. Examples shown that the software was highly operable, and it can be easily and conveniently to provide reliable information for the detection and reinforcement of the building structure and transformationThrough summarizing the research work of this article, it is feasible to apply the fuzzy comprehensive evaluation method to evaluate the vulnerability of old buildings, which can be convenient, at the same time, and based on the fuzzy comprehensive evaluation theory to write the software has the vital significance to the actual engineering.