Journal of Natural Disaster Science

EXTENDED DISTINCT ELEMENT SIMULATION OF DYNAMIC TUNNEL COLLAPSE

Motohiko HAKUNO
Professor, Earthquake Research Institute, University of Tokyo, Tokyo
and
Tadashi YAMAMOTO
Housing and Urban Development Cooperation, Tokyo

(Received 30 September 1991 and in revised form 20 January 1992)

Abstract

The Distinct Element Method (DEM), in which soil is represented as a system of numerous discrete particles, does not account for two factors; continuity of the medium and wave propagation. The extended method (EDEM) proposed by Iwashita and Hakuno has a physical structure that presents the effect of the internal material between the particles as pore water or clay. We simulated the two-dimensional dynamic fracture of a tunnel using this method. During fracture many small cracks occured throughout the medium, which formed fracture lines. Results confirmed that the EDEM can simulate a medium composed of continuous and discontinuous elements.

Key words

fracture mechanism, computational mechanics, extended distinct element method