Some Comments on “Unloading Rock Mechanics”

Abstract:

Conventional rock mechanics parameters are not derived directly from loading rock specimens in laboratory or in situ. Instead, they are determined by many different rock classification codes and criteria in different countries, and some of them such as RMR and Q systems are widely used in many countries. None of these codes and classification systems has considered the important factor of unloading of real excavated rock masses for engineering purposes until Professor Ha Qiulin proposed his new concept of unloading rock mechanics some two decades ago. Since rock masses are not a true CHILE continuum, the loading and unloading behaviors differ greatly from each other. Ha and his co-workers such as Li Jianlin have demonstrated that strength and deformational characteristics, initial rock stresses, scale effects, creep, deformation and fracture patterns are quite different and stress path dependence is particularly emphasized. All these findings have practical significance and a brief introduction and some discussions will be presented in this paper.

• Periodical: Advanced Materials Research (Volumes 524-527)
• Pages: 686-689
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.524-527.686
• Online since: May 2012
• Authors: Bao Yun Zhao, Dong Yan Liu, Ke Shan Zhu
• Keywords: Discontinuity, Excavation, Rock Engineering Properties, Space- Time-Dependence, Stabilization and Fracturing

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