Design And Construction Discussion Of Small Clear Distance Tunnel In Expressway

The small clear distance tunnel is the structure style between ordinary tunnel and multiple arch tunnel and is considered based on the rock mechanics with full use of self-supporting and the steady ability, to achieve the reasonable and economical goal. The clear distance is smaller than the tunnel which the standard stipulated possible to be called the small clear distance tunnel. The small clear distance tunnel with high economy and project value, has been arousing the interest by its unique merit not only for replacing multiple arch tunnel but also for route selection, the land takes over for use, the environment protection and so on.This paper attempted to carry on the theory and the practice discussion with emphasis in complex mountainous area based on 5 small clear distance tunnels with about 7m distance in LIUYUE expressway and a lot of reference. Provided typical actual case and summarized some design and construction thought in this paper. The main content includes: the research background and present situation, the project information of small clear distance tunnel in LIUYUE expressway, the design standard and the technical specification for using, design summary of principal part in the small clear distance tunnel project, the choice of excavating method under complex geology, construction demolition technology analysis, lock bolt support technique analysis, rock masses classification and geological prediction discussion, clamping rock reinforcement research, the typical project case - SHIZIJIAN tunnel construction, the conclusion of essential technology application and so on. Provided more detailed basis for the small clear distance tunnel construction in expressway. Make the expressway design more conform to the natural style and achieve the structure artistic, linear smooth, safe and reliable, saves the investment, convenience construction and create more social efficiency and economic efficiency.