Research On Optimization Of The Structure Design And Excavation Scheme Of Complex Cross-tunnel

With the rapid development of national communication,there are more and more construction projects of the tunnel.According to the plan of the Ministry of Communications, there are 400,000 kilometers new road will be build in 10 years,and the national arterial highway of "five verticals and seven horizontals" will be connected,and more than 155 kilometers of road tunnel will be built during the period.There will be more and more complicated structure of cross tunnel emergings in the highway tunnel in this period.The similar engineering are relatively less,there are some questions in design and operation in this new form of tunnel structure.This text has collect some results of researches in cross tunnel,introducing the situations of the research,summing up the design and construction methods of cross tunnel, which can be offer the materials to consult in the similarity projects.The research is carried on combined with the project of Qi Pan Guan tunnel,which analyzed the conditions of displacement and stress of rock and supporting structure.The article established some calculated models which are different in design parameter.Through the result of calculation,the article fixed the most optimum design parameter,which fixed the thickness of initial support being in the range of 20cm～25cm and secondary lining being 30cm.According the above parameters,four kinds of different excavated models have been built,which are used to study the dynamic construction mechanics feature in cross tunnels. After calculation of four kinds of excavate models,we can find the law which can explain rock and line's dynamic change in stress and displacement.At last combining the time of every excavate model,the text determine the most rational construction scheme.