Thermo-elasto-viscoplastic mechanical behavior of manmade rock and its numerical modeling

In this study, a thermo-elasto-viscoplastic model for soft rock is proposed to describe its fundamental mechanical behavior of soft rock such as the influences of overconsolidation, intermediate principal stress, temperature, time dependency and inherent structure with a unified set of parameters. In the model, the concepts of subloading and superloading yielding surfaces are introduced to describe the influence of overconsolidation and structure on the deformation and strength of soft rock. The influence of the intermediate principal stress is also properly considered by adopting a transformed stress tensor t(ij). To consider the temperature effect, a thermo-induced equivalent stress is introduced to consider its influence on the yielding surfaces, the evolution of the overconsolidation, and the structure when subjected to shearing loading under different conditions. By comparing the calculated results with test results of a manmade rock under different loading and temperature conditions, the availability and accuracy of the proposed model are carefully investigated, and the performance of the proposed model is verified in detail. (C) 2019 Tongji University and Tongji University Press. Production and hosting by Elsevier B.V. on behalf of Owner.