| Due to complicated topographical and geological conditions as well as large numbers of mountainous areas in China, construction of high-grade highway unavoidably meet with lots of tunnel works. As a result of special geological and topographical limitations, spacing of tunnels can not satisfy with general technical code. Therefore, special structure shapes such as neighborhood tunnel, double-arch tunnel have to be applied. However, the double-arch tunnel has a really complex and long lasting construction process. It is weak in waterproof, but strong in investment need. From this point of view, the neighborhood tunnel, whose key technology on design and construction is becoming a hot researching item, has more even greater advantages of the double-arch tunnel. So this small spacing tunnel is widely used.Based on the neighborhood tunnel of Huang Qu Nan Expressway, this paper takes numerical simulation as the main means of research, associating with the indoor model test. By comparing and confirming of the both, it draws the conclusion. The main research work are as follows:(1) Set net minimum reasonable distance of neighborhood tunnel in the rock classⅢ～Ⅴ, by the means of simulating tunnel excavation in different ground conditions,distances, state support systems.(2)Differentiate and define the middle rock pillar and its neighboring areas in neighborhood tunnel with small interval. On this basis, through the numerical simulationt, study the mechanical properties of the middle rock pillar and the effect of different reinforcing manner in different ground conditions, intervals. So we can determine the reasonable reinforcement approaches of the neighborhood tunnel.(3)Analyze the control of construction safety key technology of neighborhood tunnel with small interval,and the mechanical analysis of neighborhood tunnel with small interval in unsymmetrical pressure and heterogeneous layer.(4)Compare, confirm and supplement the two(three)-dimensional numerical simulation results via model test.
|
PDF Full Text Request