Response Analysis Of Fire And Reinforcement Research On The Large Silo Of A Coal Mine

With the rapid development of national economy, the demand for enery has been increasing continiously. As one of the main energies in China, the demand for sustained provide of coal increases. While the production capacity improves, there are many safety risks. Among them, the coal bin fire has proved to be a crucial problem which has caused tremendous economic losses and deaths. Thus a research on coal bin fire is highly required. An observation to fire causes and performance changes in structures after fire has great significance in offering accurate techniqual basis for fire prevention, structure reinforcement and reproduction.The present thesis takes a large silo strucutre of a coal mine as the project background. The analysis covers fire response of the structure, high-temperature performance of reinforced steel and concrete, and their damage mechanism. The thesis makes a comparative analysis by applying the examined data and the finite element software. A scientific estimation of the damage is made and a reasonable proposal for reinforcdement and repair is given to provide some theoretical basis and techical support for the manipulation of silmilar structure fires. According to the engineering practice, the thesis mainly do the following researches:1. The article studies the perfomance changes of steel reinforcement and concrete in high-temperature caused by fire and their damage mechenism respectively.These changes includes the stress-strain relationship, elastic modulus, high-temperature strength, temperature deformation and some other changes. A further research on the changes of bonding properties of steel and concrete under high temperature is made to provide some theoretical basis for the later analysis of data.2. The paper makes tentative field investagations which includes fire investigation (combustion types and area division, field distribution of temperature, fire duration, burning items and burning amount, etc.), the macroscopic damage of the structure after fire, and detection of structure damages (mainly including crack performance, deformation performance, and damage pattern, etc.). This paper analyzes the results of field investigation and makes a scientific evaluation of structural damages and the surplus carrying capacity.the analyses are compared with results of finite element analysis to provide certain theoretical basis for similar strucutre analysis. The article further concludes the main engineering tests and puts forward reasonable reinforcement or repair suggestions to provide certain scientific basis for further engineering reinforcement.3. The paper summarizes the commonly used methods for the reinforcement of reinforced concrete structures after fire. Based on the practical situation of the project, the data analysis and the foundamental structure strengthening theories by fire, the paper determines a reasonable program for the repair or reinforcement of the coal bin structure. The reinforcement covers the upper structure of the coal bin and its train warehouse endophram in accordance with certain procedures. After the reinforcement, the test and caculation of the horizontal bearing capacity are made to ensure the rationality and applicability of the reinforcement program and to provide some technical support for the reinforcement of similar structures.