Design of Quasi-Rectangular Tunnel Built in the Rock Masses Following Hoek-Brown Failure Criterion

Although quasi-rectangular tunnels have been widely used in underground projects, there is no related research work that was carried out to design this kind of tunnel excavated in the rock masses that followed the Hoek-Brown (HB) criterion. By transforming the strength parameters of the rocks that obey the HB failure criterion into equivalent strength parameters of the Mohr-Coulomb (MC) criterion, the lining internal forces of a quasi-rectangular tunnel are investigated in this manuscript in light of bending moments and normal forces using the Hyperstatic Reaction Method (HRM). After comparing with the values of a model test and verifying the present method, the influence of different tunnel depths, H, different rock unconfined compressive strengths, sigma(ci), and the geological strength parameter GSI on the lining internal forces of the quasi-rectangular tunnel is then investigated. The obtained results indicate that the parameters H, sigma(ci), and GSI have a significant effect on the lining internal forces of the quasi-rectangular tunnel. The work presented in this paper provides a theoretical reference for designing the quasi-rectangular tunnel support structure built in the rock masses following the Hoek-Brown criterion.

Automated summary

This study investigates the lining internal forces of a quasi-rectangular tunnel designed according to the Hoek-Brown criterion in rock masses. By transforming the strength parameters and using the Hyperstatic Reaction Method (HRM), the influence of different tunnel depths, rock strengths, and geological parameters on the lining internal forces is analyzed. The results show that these parameters have a significant effect on the lining internal forces of the quasi-rectangular tunnel.