Abstract:

Nowadays, the structural analysis method of railway tunnel in China is still an experiencedependent one, thus the subjective differences of correlative parameters (especially the loads for the models) applied are widely existed due to the operators. To minimize the influence from the differences, effective guidance and norms are required. In this further discussion of tunnel engineering situation, the loading status and relative supports are legitimately classified, not only based the rock classification but also differed by specific geological environments in the same rock classification. In this proposed method, the consideration for consistency and differentiation is well presented. A simple fact is clarified form comprehensive analysis between New Austrian Tunneling Method (NATM) and traditional mining method (MM) that loading on the lining is a longterm act. Through the comparison between the structure calculation and analysis of actual measurement, several conclusions are drawn: The collapse loads on deepburied tunnels of railway are determined by the current formula are turned out to be reasonable. The loads of Ⅱand Ⅲ levels lining structure are the collapse ones of 40%, and then the loads of Ⅳand Ⅴ levels lining structure are, respective, the collapse ones of 50% and 70%. The Ⅱand Ⅲ levels lining structure of single track tunnel is considered to be safety reserve. As the span increases, the construction, engineering analogy and structure calculation requirements should be satisfied. Meanwhile lateral pressure coefficients of all levels of surrounding rocks are used according to the specification. Through the systematic statistical analysis and experimental research,the conditions for further perfecting the structure design method are provided.

Key words: railway tunnel, project status, surrounding rock pressure, loading correction