Radial passive rockbolting in tunnelling design with a new convergence-confinement model

A new procedure for the computation of the convergence-confinement curves of a bolted tunnel is presented. The proposed model allows one to take into account the following specific conditions: the effect of the distance of the bolted section to the tunnel face, the effect of increasing the lateral spacing between bolts, and the influence of the different bolt-end plate response curves. A comparison of the results obtained by using the new procedure with those derived from numerical simulation and performance monitoring is shown to be satisfactory. Copyright (C) 1996 Published by Elsevier Science Ltd