The failure mechanism and construction practice of large underground caverns in steeply dipping layered rock masses

doi:10.1016/j.enggeo.2019.01.006

CORC > 武汉岩土力学研究所 > 中科院武汉岩土力学所 > 岩土力学所知识全产出 > 期刊论文

	The failure mechanism and construction practice of large underground caverns in steeply dipping layered rock masses
	Zhou, Yang-Yi; Xu, Ding-Ping; Gu, Gong-Kai; Liu, Ke; Wan, Liang-Peng; Wang, Tuan-Le; Yang, Jin-Bao
刊名	ENGINEERING GEOLOGY
	2019
卷号	250 期号:-页码:45-64
关键词	Layered rock mass Underground caverns Excavation Bedding plane Geological condition
ISSN号	0013-7952
DOI	10.1016/j.enggeo.2019.01.006
英文摘要	The stability of large underground caverns in steeply dipping layered rock masses is not only affected by the engineering geological characteristics of surrounding rock masses, but also by the excavation sequences and reinforcement measures. Certain places around the periphery of underground openings, such as the high sidewalls, would exhibit significant displacement increases and various failure patterns if the excavation and support were not properly designed. These issues can, according to the basic principles of structurally-controlled concept, be largely attributed to the mechanical properties of bedding planes and other discontinuities. In order to clarify the possible mechanisms behind these failures and to realize the dynamic adjustment of construction, a thorough investigation was conducted to the underground caverns of the Wudongde hydropower station throughout the excavation process. The geological conditions and mechanical properties of the rock masses in the study area were first introduced in detail. Four examples were then presented following the overall logic from geological background to failure mechanism and finally to reinforcement practice. The first example focused on the local wedge-type instability analyses, including the collection of necessary information, the identification of potential blocks, as well as the determination strategies for the factors of safety. The second example illustrated typical tensile failure mode of steeply inclined strata induced by large-scale excavation. The sudden normal unloading of bedding planes led to observable fractures along these weaknesses and considerable increases in sidewall displacements. Large quantities of extra reinforcements had to be installed to control further development of fractured range of the upstream sidewall. The third example highlighted the long-range influence of excavations on the stability of downstream roof, where multistage displacement increase and shotcrete cracking took place as a result of stress concentration and strata buckling, possibly also of the local unfavorable discontinuities. The last example was related to the failure mode of combined discontinuities on the surfaces of piers between two pits. Lessons learned from these examples mainly involve what the mechanical behaviors of the steeply dipping layered rock masses in different places after excavation will be like, and to what extent these behaviors could be predicted or anticipated, which then put emphasis on the importance of geological investigations, and how the optimization of excavation sequence and bench height as well as the timely installation of regular supports could effectively reduce the risks of instability.
WOS研究方向	Engineering ; Geology
语种	英语
WOS记录号	WOS:000461404500005
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/15043]
专题	岩土力学所知识全产出_期刊论文
作者单位	Northeastern Univ, Key Lab, Minist Educ Safe Min Deep Met Mines, Shenyang 110819, Liaoning, Peoples R China
推荐引用方式 GB/T 7714	Zhou, Yang-Yi,Xu, Ding-Ping,Gu, Gong-Kai,et al. The failure mechanism and construction practice of large underground caverns in steeply dipping layered rock masses[J]. ENGINEERING GEOLOGY,2019,250(-):45-64.
APA	Zhou, Yang-Yi.,Xu, Ding-Ping.,Gu, Gong-Kai.,Liu, Ke.,Wan, Liang-Peng.,...&Yang, Jin-Bao.(2019).The failure mechanism and construction practice of large underground caverns in steeply dipping layered rock masses.ENGINEERING GEOLOGY,250(-),45-64.
MLA	Zhou, Yang-Yi,et al."The failure mechanism and construction practice of large underground caverns in steeply dipping layered rock masses".ENGINEERING GEOLOGY 250.-(2019):45-64.