The Influence of Axial Pressure on the Yielding Behavior of Rock Mass around a Cylindrical Tunnel.
Year: 1992
Type: article
Abstract: The purpose of this paper is to clarify the effect of the axial pressure of a tunnel with a circular section on the behavior of the surrounding rock, and to classify the types of stress distribution and yielding modes. The rock mass is assumed to be elastic-perfectly plastic and to obey the linear Mohr-Coulomb yield criterion as well as the associated flow rule of the theory of plasticity; hence dilation is included. It is also assumed that a rock behaves in accordance with the condition of plane strain, and that the internal radial pressure decreases as the excavation of a tunnel proceeds. As the internal pressure is decreasing, yielding occurs. There are three different modes and two other composite modes on this primary yielding stage. As the internal pressure is further decreasing, the primary yielding stage gets into the secondary yielding stage, where the yielding mode is different to that in the primary stage. The variations of yielding pressures, plastic boundary radii and tunnel closures are given as a function of far-field rock pressure ratio. It is concluded that the axial pressure exerts a greater influence on the yielding behavior of the surrounding rock mass, and that hence the axial pressure is an essential factor in the elasto-plastic analyses of a tunnel.
Source: Shigen-to-Sozai
Authors: Masao NISHIMURA, Toshiaki SAITO, Makoto TERADA
Institutions: Okumura (Japan), Kyoto University
Language: English
Topic: Rock Mechanics and Modeling
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2319089539