Evaluate the influence of the excavation geometry of full-length construction on the longitudinal deformation of the existing tunnel when constructing the excavation using an analytical approach

In constructing structures using excavation methods in large cities, one of the greatest challenges is protecting existing underground structures from adverse impacts during the construction process. Reducing the load due to the excavation activities above can lead to undesired behaviors and potential damage to underground structures, especially those requiring high safety standards, such as TBM tunnels. This article proposes a simple method to assess the influence of excavation parameters when constructing the full-length tunnel axis displacement of TBM tunnels during upper-level excavation pit construction. Initially, stress changes are determined when excavating soil at the tunnel face, and then tunnel deformation is determined using analytical methods. The analytical results were also compared with the results from a 3D model, yielding minor discrepancies. Thus, this analytical method allows for the assessment of the influence of excavation parameters on the deformation of existing tunnels.