Longitudinal cracks in pressure tunnels

Abstract

Based on the non-linear finite element analysis, the maximum bearing capacity of a plain circular concrete lining subjected to external and internal pressure is investigated. Numerical results regarding elastic stresses and deformations are compared with those calculated using the classical thick-walled cylinder theory. Referring to the discrete cracking concept and assuming that the concrete behaves as a brittle material, the redistribution of stresses after cracks have occurred is further investigated. The normal tensile strength in the lining will reduce to zero as soon as the joint element is cracked. These analyses confirm that the proposed modelling method may be used satisfactorily, to model the cracking process of passive pre-stressed circular concrete linings.