Wall displacement prediction of circular, D shaped and modified horseshoe tunnels in non-hydrostatic stress fields

The prediction of the magnitude and development of the expected displacements has an important impact on a large number of issues during tunnel construction. Convergence confinement method (CCM) is based on the analysis of the stress and strain state that develops in the rock around a circular tunnel capable of determining wall displacement. The radial displacement given by RocSupport that is based on convergence-confinement method (CCM) is valid for the tunnel circular cross section driven in the hydrostatic state of stress. In this paper several equations and graphs are presented using numerical modeling (FLAC3D) to obtain corrective coefficients to be applied to the values of wall displacement of circular tunnels in hydrostatic state of stress given by analytical method (RocSupport) for the prediction of maximum wall displacement and displacements of different parts of circular, D shaped and modified horseshoe tunnels in non-hydrostatic stress fields.

► We simulated three types of tunnels by FLAC3D in different depths and stress fields. ► We determined maximum displacement at different parts of the tunnels. ► We compared the FLAC3D results with the analytical method result (RocSupport). ► We presented equations for wall displacement prediction of the tunnels. ► Error analysis of equations shows the capability of presented equations.