Operation Ventilation System And Key Technology In Qinlin Zhongnan Mountain Highway Tunnel

With the high-grade highways in the large-scale construction of the western provinces of China, an increasing number of highway tunnel, the scale is also growing. Long highway tunnel ventilation problems in the construction and operation phases are very important, and this is one of the main problems to restrict china long highway tunnel design and construction. Ventilation directly affects the tunnel's Security Operations, project investment, emergency rescue and passenger's health and safety. At present, the effective protection of ecological environment and land resources under the strategic guidance, domestic long highway tunnels have been started, the construction of increasing the number of ventilation shafts, but in the shaft design and construction experience is not mature, it is necessary for the issues.The Qinling tunnel project for the engineering background, using research, theoretical analysis and numerical simulation of long highway tunnel ventilation system from the overall layout, system components, detailed design, tunnel construction and other aspects of group discussion and analysis, focus on determining the position of the shaft engineering, structural design, shaft construction were analyzed, the results show that:(1) Qinling zhongnanshan tunnels ventilation system of reasonable, comprehensive, to meet the long tunnel ventilation and rescue needs. Underground ventilation shaft works related to engineering and can better coordinate the overall idea of the design verification practices by the project.(2) Different shaft characteristics and conditions of the selected works of reasonable construction scheme is to ensure the smooth construction of large diameter, the premise of deep shaft. Qinling highway tunnel ventilation shaft on the 2nd shaft by driving forward method,1 and 3 using raise boring method, smooth construction, initial support structural stability, safety and reliability of secondary lining.(3) For depths less than 400m, with a ballast duct bottom conditions and relatively simple geological conditions can be counter-shaft works well construction method, construction method with the construction of Shaft speed, save construction cost and other outstanding advantages; for the depth of over 400m, complex geological conditions, bottom conditions do not have a ballast shaft works well to select full-face method is the construction plan, construction of the whole section is well method works with a large deep shaft construction risk control, construction progress, project quality assurance and so on.(4) In the condition of low temperature, if plain concrete were used as the shaft clapboard, the stress of which can not satisfy force requirement. So reinforced concrete structure should be adopted.The study fruit of this paper effectively instructs interrelated safety construction relying on the project, and the ventilation effect is in perfect and ideal condition, which can be used as reference for railway and civil underground projects and other analogous projects.