Research On Construction Technology Of Vertical Shafts Of Highway Tunnels

With the rapid development of the highway traffic in our country, there will be more and more ventilation vertical shafts of highway tunnels needed to be constructed. Although the mines and hydropower stations at home and abroad possess relatively mature technology, most relevant researches focus on how to raise the extent of the mechanization level of construction and how to increase the tunneling distances per month. In view of the highway tunnels have the following features such as the sections are large, the depths are shallow or they are often situated in the lofty ridges or towering mountains, it is necessary to study simple, economical, experimental friendly and safe methods for the construction.According to Kuocangshan tunnel shaft project, this paper summarizes a set of simple, easy and economical methods about construction on the shafts of highway tunnels, and then probes into and analyzes some key technologies. Based on the above results, the paper continues to study and discuss the relationships of the main technological processes, and set up the method and model about the optimization. The study indicates that it has great potentialities of reducing the construction cost by optimizing technological processes, and it can supply the optimization schemes for the similar projects in the future. Finally, this paper investigates initial support on the jet concretes of the tunnels, and makes comparisons between steel-fibre and common jet concretes about their performance and cost. The results indicate that the performance of the steel-fibre concretes is better than that of common concrete. The overall cost of the steel-fibre concretes does not increase, but at present they have not been approved by the construction enterprises. So we have to wait for the conclusion after their applications have spread.