Selection of construction method for large section soil tunnel and analysis of monitoring results during construction period

Relying on the background of large section soil tunnel engineering, the numerical simulation on three excavation methods for soil tunnel including bench method, arch heading method and cross diaphragm were carried out. Results show that the arch heading method is confirmed as optimum for this project by comparative analysis. And then, according to the monitoring results of the arch heading method, stress development laws and deformation characteristics of surrounding rock and supporting structure of large section soil tunnel were obtained, which include regression analysis functions of the development trend of vault settlement and horizontal convergence, distribution characteristics of ground surface settlement, development law of primary support stress and contact stress between surrounding rock and support, influence scope of tunnel face excavation and corresponding deformation law of surrounding rock as well as main deformation stage. Besides, the reliability of simulated results is verified by comparing them with the monitoring measurement data.