Rational design concept for inverted arch structure for mountain tunnel

One of the typical countermeasures against ground heaving in mountain tunnels in service is reinforcement by installing or refurbishing new invert, but there are many problems in terms of workability and economy. The purpose of this study is to propose a concept and load-bearing capacity that will contribute to the selection of rational reinforcement measures. As one of the methods, inverts with new shapes were assumed as reasonable structures, and their load-bearing capacity and structural feasibility were examined by model experiment and numerical analysis. As a result, it was confirmed that the behavior during deformation and the tendency of the stresses generated differed depending on the shape of the invert. In addition, there are some cases where it is possible to have a certain load-bearing capacity and expect reinforcement effects in rational construction.