ABSTRACT
This paper investigates the influence of twin tunnels with respect to the twin-tunnel interaction and stability of tunnels running through slopes within weak rockmasses based on the slope angle and the quality of the in-situ material and rockmass strength. This work involved the use of 2D Rocscience numerical models of tunnel sequencing for numerical simulation of composite material behaviour and sequential tunnel deformation response. Validation data was obtained from the field for tunnels that were excavated as part of actual tunnels in Europe. The goal of the research is to highlight the use of numerical analyses tools and the selection of constitutive relationships for such analyses at the design stage whereby geotechnical risks can be determined prior to tunnel construction within slopes. Additionally, it is of interest the implicit influence of tunnel construction within slopes at a shallow overburden for different topography and rockmass quality cases with respect of slope stability and the potential shear failure mechanisms.
