Elastoplastic analysis of the effects of the advance of a double-track railway tunnel on the soil and on the tunnel support. In-situ testing and 2d modelling

Abstract

This study involves an elastoplastic analysis of the effects of the advance of a double-track railway tunnel on the soil and the tunnel support. The strength and deformation properties have been determined using in-situ testing with equipment designed and patented by the Soil Engineering Research Group at the University of Oviedo (GIITUO). The behaviour of the excavation face and the ideal trace are studied using a 2D model of the longitudinal cross section of the tunnel. In this work one study of the behaviour of the soil and the support during the different phases of excavation is given. From it, it is possible to say that in the initial phases of the excavation and with temporary support there are not significant deformations. Once the final support is applied, the maximum compressive stresses (7MPa) are concentrated in the crown zone and the maximum tensile stresses are in the base of the support of the top heading and the sidewalls (0.15-0.5 MPa