| China is rich in mountains. The construction of highway tunnel cannot be avoided in order to develop the traffic net between cities and mountain villages. The double-arc tunnel can develop better than others with many advantages in the area of cities and mountain villages. In recent years, the double-arc tunnel used in cities can be highly appreciated by designers because of the better construction technique, and there are some other advantages, such as less land occupation, environmental tunnel portal. Therefore the double-arc tunnel can develop better than others with many advantages in the area of cities and mountain villages. Although, the double-arc tunnel construction in our country has developed to some extent, there are also some shortages in design and construction. And the double-arch has some problem after completion. So in order to develop the construction of double-arch tunnel, it is necessary to make further research for double-arch tunnel. The distance problem between the face of left tube and the face of right tube and, the construction time problem of middle wall all can be analyzed by numerical simulation based on the double-arch tunnel in Xia Men Jin Bang mountain. After analysis, the related laws of surrounding rock deformation can be obtained during the construction of double-arch tunnel to provide some reference data for the construction and design of double-arch tunnel like Jin Bang mountain tunnel. Some results can be got as the following:(1) With the three rock conditions (three grades, four grades and five grades) built, the Jin Bang mountain double-arch tunnel three-dimensional numerical model can be built to simulate the tunnel deformation and stresses variation of middle guide tunnel influenced by rock bolting during construction. It can be found that the bolt supporting effect under the five grades surrounding rock condition is better than the condition in the three and four surrounding rock, and the distributed characteristics of the axial force of the anchor in middle guide tunnel also can be got. All these results can provide some reference values for design and construction.(2) The numerical simulation analysis can be made for the five different distance (6m, 9m,15m,21m,30m) conditions between the right tube face and left tube face, which can get the reasonable distance between the right tube face and left tube face is double of the diameter of tunnel.(3) The advantage and disadvantage under different construction process can be got with analyzing the force and deformation condition that can be obtained by simulated the tunnel under five grades surrounding rock. Therefore the reasonable suggestion about construction can be put forward.(4) With the contrastive analysis between The observational method result, such as Vault crown settlement, level convergence, surrounding rock pressure and the result got from numerical simulation, the surrounding rock stress and displacement rule can be analyzed further during the excavation of tunnel, what's more, the reason why can produce difference between the numerical simulation and observational method result reason that can be got after the analysis. |
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