Researches On Ventilation Design And Control Technology Of Zhongnanshan Super-Long Highway Tunnel In Fire

Since the risk of tunnel fire will become higher with the increase of total length of highway tunnel, safety problems of tunnels have become an increasing concern due to the huge damage of fire. With the length of 18020 m, two-hole one-way traffic, and multi-ventilation shaft, Qinling Zhongnanshan super-long highway tunnel is totally different from any other tunnels in fire ventilation, so it's definitely necessary to conduct researches on its fire ventilation.In view of this, based on the project of Zhongnanshan super-long highway tunnel, combined with the project of Zhongnanshan highway tunnel comprehensive disaster prevention and rescue Technology Research (20013180007103) supported by the Chinese Western Road Construction Scientific and Technological Project, ventilation design and control technology are detailed studied with the application of theoretical analysis aided with experimental and numerical method in this dissertation. These achievements are not only supportive of the technology of Zhongnanshan super-long highway tunnel's planning, design, construction and operation, but also of great guiding significance in ventilation and disaster prevention and rescue technology of China's super-long highway tunnels. Thus, it especially accumulates useful date for the amendments of norm. So, what this dissertation mainly discusses lies in the following areas:1. With certain conditions simplified, a tunnel temperature vertical drop of the theoretical prediction formula is established. By studying the tunnel wall temperature over time, the factors deciding how the instable thermal transmission coefficient changes with the smoke and heat exchange among walls have been obtained. In addition, such determining factors as time and space of vertical temperature distribution have been gained with the heat exchange coefficient of smoke and tunnel walls introduced and the coefficient of heat transfer taken into consideration.2. Through the study of density distribution in tunnel fire, the formula for computing the fire pressure is gained. Because of the significant change of super-long highway tunnel fire temperature, formula for computing fire pressure and smoke frictional resistance have been figured out according to the different sections of the temperature change .3. With the research on ventilation control of single tunnel fire, it is decided that the critical wind speed is 2-3m/s; on this basis, ventilation control in tunnels with transverse passages in fire, as well as ventilation control standards for different fire locations in multi-shaft tunnels, has been clearly set up for the first time as considerable experiments have been carried out.4. A software named "long road tunnel fire ventilation network program" that can automatically complete computing the air volume of each branch and the numbers of fans of long road tunnels in fire has been developed. By computing the ventilation of Zhongnanshan super-long highway tunnel in fire with the software, the arrangement of fans set in all fire protection sections have been well made, which provides a basis for the design of tunnel fire emergency preplans in computation.5. The general principles of fire relief system, rescue system, fire compartmentation and method for fire emergency preplans have been established. By probing into tunnel fires deeply, on the basis of ventilation and combined with the project of Zhongnanshan super-long highway tunnel, a card-fire rescue plan and an integrated ventilation control system for tunnel fire have been worked out in this paper, which can guide the actual disaster relief work.