Constraction Technology And Numerical Simulation Of Ventilation Shaft In QinLin ZhongNan Mountain Highway Tunnel

With the gradual enlargement of the basic traffic construction scale in recent years, the scale and quantity of the highway tunnel project has increased day by day. Tunneling ventilation in operational period was one of the key technical problems in constructing the large tunneling engineering. And one of the effective ventilation ways is that the shaft is ventilated by stage. However, because the shaft built in tunnel of domestic highway is few in quantity at present, there is no ripe experience in design and operation, so it is necessary to carry on further investigation on this problem.On the basis of consulting the materials in domestic foreign language, which was summed up in the paper that the construction method of shaft construction by combine the actual construction situations of three ventilation shaft in the QinLin ZhongNan Mountain highway tunnel and by surveying,analyzing,calculating and scheme selecting. Which was considered in the paper that the front well drill method and single process working through all rockshaft method was adopted in the 2nd ventilation shaft ,that is to say the constructive method which dig-in one time in all design section and the small-scale excavating machine was adopted to clear the soleplate,load rock scraps can saving the time of the working operation shift and the time of assist working was a effective method of quick dig-in in shaft construction. To the 1st and the 3rd ventilation shaft, which was considered in the paper that the back well drill method which named raise borer method was adopted in shaft construction not only can reduce the difficulty of construction and assist the project, improve working efficiency greatly, but also can accelerate the project progress. This construction method was accumulating experience in the tunnel shaft constructed in the future.In addition, the paper discussed the character and technics of the slip-form constrction and put forward solution and technical quality control measures for problems emergeing during the slip-form constrction. The measure,proved in actual constrction,could not only ensure engeering quality,but also the safty and schedule.Finally, whereas the influence of cave on vertical shaft structure stabilization,FEM dynamic simulation was taken on the surface constrction of vertical shaft. Based on the analysis of stress field coming into being during each step of cave, the constrction measure, taken by the 2nd ventilation shaft of Zhongnanshan highway tunnel in Qinling was proved feasible and safe.This paper, taking the constrction of 2nd ventilation shaft of Zhongnanshan highway tunnel in Qinling as the background, primarily analyzed rapid-constrction technique, dynamic simulation was also taken on the vertical shaft constrction, which analyzed the structure safety and feasiblility of constrction. The research results guides effectively rapid-constrction of ventilation shaft, also offer reference for the similar project...