Adaptation Of Shed-tunnel Structure, Backfill Buffer Body And The Mountain

With the development of the highway construction, urban road has basically been able to meet the people’s access travel requirements, and highway construction has expended to mountains. China is a mountainous country, mountain highway tunnel began to appear and gradually develop toward longer and greater direction. During the rapid development of highway tunnel in mountain area, reducing the phenomenon of deep-cut and high-fill, protecting the highway landscape and ecological maintenance have become the guidelines.Shed-tunnel has an important role in the mountain road environment and disaster prevention and mitigation. The structure which is adopted according to the natural topography, such as shed-tunnel or half-tunnel, should be adopted to protect the natural environment and slope in the complicated zone combining anchor-shotcrete with shed-tunnel structure, reasonable and complete supporting system of the slope was formed.This paper is according to the shed-tunnel of Zhongshan Golden, which from Jiangmen to Luoding highway of Guangdong Province. And develop monographic study for highway construction of environmentally friendly technology. Through the different coefficients of load releasing of slopes and stiffness of back filling to categorize and group, then contrast and analysis the law of internal force changes of shed-tunnel. In order to study the interaction mechanism and applicability between the shed-tunnel structure, the backfill buffer body and the slope. Main research work of this thesis is as follows:First, this paper summarizes potential data of shed-tunnel at home and abroad in recent years, and summarizes the classification and characteristics of shed tunnel structure of shed tunnel structure. Shed-tunnel not only decrease earthwork, but also could integrate nature easily.Second, use the finite element software--Midas/GTS, through the establishment of the physical and mechanical model of shed-tunnel structure, comparing the mechanical characteristics of shed tunnel structure in different conditions, and the applicability of different forms of shed tunnel are summarized.Third, According to the engineering, use the finite element software--Midas/GTS, Shed on the interaction mechanism cave structures, back filling buffer between the body and the slope of the body and expand the applicability of research.Studies have shown that: under the same conditions of slope, with the increase of coefficient of load releasing,that the later construction of shed-tunnel, the smaller inner force of shed-tunnel. So consider the structure forces from the shed-hole angle, shedtunnel should slope deformation after construction. And the slope crest displacement, tensile stress at the foot of slope, the plastic zone is larger. The conclusion of the slope stability is poor. Therefore, from the point of view of slope stability, shedhole should be applied as soon as possible. Designed to be taken into account, only makes the cave shed smaller force, but also makes a good slope stability, you must select the appropriate facilities for the opportunity shed hole, can be determined by measuring the slope monitoring methods.In the same slope conditions, with the increase of earth and rock backfill stiffness, shed cave force is smaller. When the stiffness 5000 MPa, the shed moment hole structure reaches the minimum value. Stiffness after more than 5000 MPa, have increased in value the moment, but the increase is very slow. Shed hole axial force and shear force values has been showing a decreasing trend. But after reaching 5000 MPa decrease is not very obvious. With the earth and rock backfill stiffness increases, slope displacement, the smaller toe plastic strain, slope stability, the better. Therefore, we can consider the slope between the shed and the use of structural rigidity hole about 5000 MPa backfill material to improve stability, reduce force structure shed-hole.Finally, summarized the design and construction experience cave shed abroad in recent years, put forward in the future design and construction need to be aware of some problems, hope for the future of design and construction to provide the appropriate reference.