The criterion for dividing the surrounding rock EDZs of underground caverns based on the energy dissipation degree

• DOI: 10.1371/journal.pone.0288324
• Publication Date: 2023-07-28T17:34:20Z
• Authors: Xianliang Wang; Jianhai Zhang; Li Qian; Tianzhi Yao; Zuguo Mo; Jianhua He; Ru Zhang; Changgui Zhao; Zanbo Qiao
• Keywords: Overburden pressure; Degree (music)

An energy calculation parameter named the dissipation degree ( R Ud ) is introduced based on analysis of mechanism and evolution characteristics during conventional triaxial tests granite Shuangjiangkou. The deviatoric stress‒strain curve rock can be divided into five stages using four stress thresholds (crack closure σ cc , crack initiation ci damage cd peak p ), which also correspond to Udc Udi Udd Udp degree–strain curve. A given threshold increases with increasing confining pressure; however, a basically stable under different pressures. Then, new criterion for dividing excavation damaged zones (EDZs) in surrounding underground caverns monotonically degree‒axial strain relationship proposed, it allows classification types through quantitative thresholds. Based EDZs mass cavern, rocks cavern group Shuangjiangkou Hydropower Station are analyzed. distribution obtained by numerical simulation calculations same as those situ elastic wave tests. However, -based method classifying has obvious advantage being able probe boundaries undamaged zone (UDZ) more explicitly, while velocity testing not sufficiently explicit. zoning provide support design advice rock, such method, length free section anchor prestressing anchor, etc.