Research On Optimized Combination Design And The Construction Scheme Of Symmetry Multi-arch Tunnel

In recent years, the construction of the double-arch tunnel in our country gets great development. A lot of double-arch tunnels are set up successively in the high grade highway and the city roads all over the country. At the same time, many excellent results on theory research and construction experience were obtained.Double-arch tunnels have special merits of reasonable structure, the minimum use of the land and the protection of natural environment. However, there exist several shortages in double-arch tunnel which limit their advantage exertive, such as water seeping and leaking in middle wall, cracking in the lining and miscellaneous construction procedures.This dissertation analyzes the problems of symmetrical double-arch tunnels in structure design and construction. The comparisons with different middle wall's position of double-arch tunnel and the parameters in different models are made by using finite element software ANSYS and the cloud graph of maximize stressσ_B of the arch bottom obtained in this paper are compared with the one in normal model. A conclusion is derived, that is, the value ofσ_B in normal model is similar to the one in the model given in this paper when P=60. This dissertation carries on the summary of construction method of the double-arch tunnel, and then from the point of view of reducing construction procedure and the disturbance of the wall rock, easing the labor strength, improving the work effect, shortening the work period and lowering the engineering expense, the method of enlarging digging of leading hole is put forward. Based on the analysis of the damages type in double-arch tunnel and the numerical calculation of ANSYS, an optimized combination design was carried out. Aiming at the main diseases, the improvement to the medium wall, arch structure and the anchor are discussed. According to the research on the materials collected about double-arch tunnels and the numerical analysis of ANSYS, the different middle wall's position of double-arch tunnel and construction plans are discussed in this dissertation. And some new ideas are put forward, which could have the benefits to the design and constructions of the double arch tunnel.