Applicability of Distinct Element Method to Model Tests of Irrigation Tunnels

Abstract

The maintenance of damaged irrigation tunnels has become a major social concern; and thus, evaluating the damage conditions of current tunnels is of crucial importance. Voids behind the tunnel lining may be created during or after construction by the conventional method, and these voids are the main factors in its failure. Hence, it is imperative to comprehend the behaviors of the ground, the tunnel lining and the voids. This paper presents model tests of the interacting behaviors between the ground and a tunnel lining with voids under loading conditions. The experimental results show that the longitudinal and lateral convergences are large in the case of a void of 90 degree angle. To investigate the local deformation and the damage pattern, the three-dimensional distinct element method is applied, incorporating the Concrete Particle Model, and the numerical results are compared with the experimental data. The comparison clarifies the qualitative evaluation of the deformation behavior of the tunnel in the model tests by the numerical method.