Excavation cycle times recorded during sinking of a deep shaft in crystalline rock – A case example at Ventilation Shaft of Mizunami URL, Japan

Sanada, Hiroyuki; Sato, Toshinori; Horiuchi, Yasuharu; Mikake, Shinichiro; Okihara, Mitsunobu; Yahagi, Ryoji; Kobayashi, Shinji

doi:10.1016/j.tust.2015.06.012

Cited by 4 publications

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“…It was found that the orientation of the major in situ principal stress is between N26°W and N35°W in the horizontal plane. e shaft was excavated using short rounds of full-face drilling and blasting, which is an approach that is widely used for shaft sinking [41]. e advance length in each excavation round was set to 4.0 m, and each excavation cycle took about 24 hours.…”

Section: Case Study Project Descriptionmentioning

confidence: 99%

Evaluating the Impact of Blast‐Induced Damage on the Rock Load Supported by Liner in Construction of a Deep Shaft: A Case Study of Ventilation Shaft of Micangshan Road Tunnel Project

Fang

Yao

Walton

et al. 2020

Advances in Civil Engineering

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The rock load acting on the lining of an underground excavation is influenced by multiple factors, including rock type, rock mass condition, depth, and construction method. This study focuses on quantifying the magnitude and distribution of the radial loads on the lining of a deep shaft constructed in hard rock by the so-called short-step method. The blasting-induced damage zone (BDZ) around the shaft was characterized using ultrasonic testing and incorporated into the convergence-confinement method (CCM) and 3D numerical analyses to assess the impact of BDZ on rock loading against the liner. The results show that excavation blasting of shafts is an important controlling factor for the degradation of the rock mass, while the orientation and magnitude of the principal stress had a minimal influence on the distribution of blast-induced damage. The analysis shows that increasing the depth of blast damage in the walls can increase the loads acting on the lining, and the shear loads acting on the liner could be significant for shafts sunk by the short-step method in an area with anisotropic in situ stresses.

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Section: Case Study Project Descriptionmentioning

confidence: 99%