Analysis on construction stability of shallow tunnel with unsymmetrical pressure and small clear distance

Abstract

Taking Georgia’s E60 Highway No. 3008 tunnel as the engineering background, a finite element calculation model was established for the construction stability of the shallow buried and unsymmetrical section of the tunnel exit, and the slope displacement and deformation and the construction dynamic characteristics of the supporting structure were analyzed. Finally, through analysis, the dangerous parts in the construction process are obtained. The analysis results show that: it is safe and feasible to simultaneously excavate the entrance section of the tunnel with unsymmetrical pressure and small spacing using the full-section method. The slope settlement process roughly goes through three stages: rapid change stage, slow change stage, stable stage, and the position stability of the slope toe is more sensitive to the overall construction of the tunnel. The maximum vertical settlement occurs at the position of the vault at the end of the tunnel, and more attention should be paid to this position during the construction. The research results can provide a certain theoretical reference for the construction of similar road tunnels in Europe.