Enhanced theoretical approach for predicting the tunnel response due to deep excavation above

Abstract

The deep excavation will inevitably cause the surrounding soil to move freely, which will have a significant impact on the existing tunnel’s response. The majority of theoretical studies focus on the mechanical equilibrium analysis of tunnel units, rather than selecting the energy method to analyse the soil-tunnel interaction. In this paper, the Rayleigh-Ritz method is utilized to replicate the distortion of the existing tunnel by considering the energy relationship. Moreover, the establishment of the potential energy equation for the existing tunnel can be achieved through the utilization of the Kerr foundation. The variational tunnel deformed energy solution is solved by selecting the minimum potential energy principle, and then the analytical resolution of the tunnel response resulting from the excavation above is obtained. The suggested method’s soundness is evaluated by contrasting it with two field case studies taken from prior research. When compared to the Winkler- and Pasternak-foundation model, which deviated from the proposed method, the outcomes obtained through the proposed method exhibit a closer resemblance to the measured data. According to additional parameter studies, the diameter and depth of the existing tunnel, as well as the elastic modulus of the soil, are significant factors that contribute to the tunnel response caused by the excavation above. The suggested theoretical solution can be utilized to anticipate the potential hazard of the existing tunnel caused by the excavation above in a pertinent engineering project.