Numerical analysis of time-dependent behavior of Siah Bisheh Cavern

Abstract

The understanding of time dependent effects or creep behavior is important in further development of knowledge in the field of rock mechanics. Increasing pressure on support system because of creep behavior of rock is one of the most important problems in underground structure which surrounded with weak rock mass. This paper presents a time dependent behavior analysis of Siah Bisheh pumped storage powerhouse cavern with complex geometry, available geological formations and diverse geotechnical properties of rocks, is under construction on the Chalus River at the north of Iran. Because of the fractured and jointed rock mass, the Discrete Element method Code 3DEC used to compute convergence and pressure on the support system. The power constitutive creep model which is able to model the primary and secondary creep regions of rock masses is applied. In this paper, results of the Siah Bisheh cavern as a case study de align with a comparison between long - term deformation data from in situ measurements and obtained data from an analytical solution and numerical simulations with special consideration of anisotropic effects will be presented. The differences between the obtained values might be because of discontinuous media or different inputs parameters were used for analysis.