Study On A Certain Tunnel Construction Ventilation Thermal Environment In High-Latitude Cold Regions

Some problems may be caused during the process of tunnel constrauction, because of the low temperature in high altitude cold regions, such as frost damage problem of portal section, low personnel and mechanical efficiency. A good knowledge of tunnel construction ventilation and thermal environment is the precondition for scientoific and reasonable construction in high altitude cold regions. This thesis, on the basis of the tunnel constrauction project built by China Railway Tunnel Stock CO, aims at tunnel construction ventilation thermal environment in high altitude cold regions by meathods of field investigation and numerical simulation. The main research content is as follows:Firstly, on the basis of the field investigation of the a certain tunnel constraction project, this thesis mainly introducts characters, consraction organization and technology of tunnel constraction project in high altitude cold regions; it makes a sense of the laws of thermal environment, the initial rock temrature and air leakage of duct joint; this thesis establishes construction ventilation system numerical calculation model, then verifies the rationality and correctnes of this numerical calculation model.Secondly, in order to solve the difficulties in tunnel thermal environment solved by means of numerical simulation, such as short time step, large calculation scale, long calculation period, large amount computation time, this thesis puts forward a idea that we can use the similarity principle in tunnel construction environment simulation to decrease the simulation and cost time. Theoretical analysis and numerical calculation prove that this idea is feasible.Finally, this thesis makes a two-year study on construction ventilation thermanl environment in which the initial rock temperature and air leakage of duct joint are taken into consideration with the use of FLUENT. Then this theis analyzes the tunnel constration ventilation thermal environment and frost damage laws in high altitude cold regions.