Study On The Temperature Distribution And The Safety Of Structure In Highway Tunnel Under Fire Cases

With the development of China’s national economy and the improvement of peoples life, the traffic volume and the frequency of the highway tunnel is increasing, the risk of traffic accidents which happen in the tunnel that cause fire also continues to increase.Fire harzard caused damage to the tunnel lining structures,for example burst, falling block, the intensity of the reduction and so on,which caused a great threat to people’s lives. People began to focus on the characteristics of lining structure after the fire damage and the safety evaluation, and then carried out a series of studies.In order to study temperature distribution of lining and surrounding rock, and the damage situation of tunnel lining structure, and the influence of various factors on the stability of tunnel lining structure in highway tunnel under fire cases, the temperature distribution and the overall safety of the lining of the highway tunnel were studied in the paper, which based on the Dushan to Pingtang highway tunnel project. The main research contents were as follows.1. Based on the field test, the temperature distribution in the tunnel lining and surrounding rock was obtained, and compared with the experimental results and numerical simulation results to verify the correctness of the numerical simulation. At the same time, the temperature and internal force in the concrete and lining structure of the fire under high temperature were further understand and mastered based on the straight beam indoor test, to provide basic data for the further validation of the numerical model method.2. The temperature distribution of tunnel lining and surrounding rock were studied based on the numerical simulation under different fire scale, different fire time and different fire retardant coating thickness.3. The tunnel lining structure local damage was obtained based on the field test, and the mechanical properties, damage scope and depth of lining structure are studied.4. The internal force and safety of tunnel lining structure were studied based on numerical simulation under different fire scale, different fire time and different fire retardant coating thickness.