Specialty Underwater Railway Tunnel Model Test Of Fire Spreading Law

With the development of underwater tunnel construction as well as construction technology and especially increasingly prominent merits of underwater tunnels in recent years in particular, an increasing number of long and super long underwater tunnels appears.However, China has few tests research or theoretical analysis on super long underwater tunnel fire spreading of high-speed railway. Thus, research on key disaster prevention is extremely urgent.With the super long underwater tunnel called Shiziyang as research subject, the thesis sets up a scale tunnel model with a length of 52.5 m to carry out fire tests by means of Froude simulation theory, making model test on fire spreading law of super long underwater tunnel.Research results are as follows:First of all, with 63KW fire power and different tunnel gradients, the thesis conducts a series of on-spot fire tests and measures smoke temperature field, velocity field and density field in the model tunnel, getting tunnel vault temperature, velocity and visibility longitudinal distribution rule at the height of 2 meters when smoke is exhausted without ventilation and vertical ventilation.Secondly, with 63KW fire power, different tunnel gradients and different wind velocities under different vertical ventilation, the thesis carries out test on maximum temperature near tunnel vault, making modification as well as comparison between test data and Kurioka theory prediction model and thereby obtaining modified tunnel vault maximum temperature theory prediction model.Thirdly, through theoretical analysis and combining empirical formula, the thesis establishes smoke circumfluence length theory model and critical wind velocity model, making comparison between theoretical model prediction result and model testing data as well as previous theoretical model prediction result. The result demonstrates that the three results are close to one another, which means that theoretical model set up in the thesis can meet engineering prediction's need.Through a scale tunnel model on-spot test, the thesis is of great significance to and provides practical guidance in comprehensive disaster prevention in shield tunnel of super long passenger dedicated lines.