Study on the Temperature Distribution Law of Thermoelastic Coupling Field in Concrete Pavement under Tunnel Fire

Abstract

Much research work about tunnel fire focused on a single temperature field of tunnel lining structures, and ignored the thermoelastic coupling effects in concrete pavement. Normally, the simplified heating curve sush as the environment temperature curve was adopted, therefore, a mathematical model of the thermoelastic coupling field was established based on finite element method, and the solving algorithm using finite difference method was proposed to analyze tunnel fire problem. Moreover, the results by the above method was also compared to those without considering thermoelastic coupling effects. In addition, the influences of material parameters, such as heat conductivity coefficient, specific heat capacity, elastic modulus and so on, were studied respectively to give the sensitivity of the problem. Through this research, the following conclusions were obtained: the thermoelastic coupling has a certain impact on the temperature field, and it appears the hysteresis phenomenon along the depth direction. Furthermore, when considering the thermoelastic coupling, the temperature of tunnel pavement under fire decreases with the increment of each material parameter respectively, i.e. all the material parameters have similar effects on the temperature field.