Effect of excavation length of inverted arch in one step on stability of multi-arch tunnels in loess

The reasonable excavation length of inverted arch in one step is an important parameter to the construction of multi-arch tunnels in loess,and it can reduce engineering accidents and accelerate tunnel construction.The effect of different excavation lengths of inverted arch in one step was analyzed by use of the finite element method and model tests.According to the final results of analysis,a reasonable excavation length of inverted arch in one step was put forward and applied to the construction of multi-arch tunnel in loess.