A rockburst intensity criterion based on the Geological Strength Index, experiences learned from a deep tunnel

Autor: Xia-Ting Feng, Hu Lei, Guang-Liang Feng, Zhang Wei, Niu Wenjing, Xiao Yaxun, Zhi-Bin Yao
Rok vydání: 2020
Předmět:
Zdroj: Bulletin of Engineering Geology and the Environment. 79:3585-3603
ISSN: 1435-9537
1435-9529
DOI: 10.1007/s10064-020-01774-2
Popis: The occurrence of rockburst is related to the surrounding rock stress and geological rock mass strength. Rockburst occurs frequently during the construction at a deep tunnel in southwest China (a tunnel with a depth of approximately 2080 m, and a length of 13 km), leading to casualties, damage to construction equipment, and schedule delays. The application of the rockburst criteria based on the stress-strength/strength-stress ratio shows that they are not suitable for the construction stage. This paper suggests a simple and feasible rockburst intensity criterion based on the Geological Strength Index (GSI) for the construction stage. In this criterion, the strength of the rock mass exposed during excavation is estimated by the Hoek-Brown criterion and is used to reflect the geological conditions of the surrounding rock, considering the influences of the joint conditions and engineering disturbance. The maximum principal stress along the tunnel is obtained by the in situ stress inversion. The ratio of the rock mass strength to the maximum principal stress (σcm/σ1) is taken as the evaluation index. The criterion is as follows: σcm/σ1 > 1.2, none rockburst; 0.75
Databáze: OpenAIRE
Externí odkaz: