Swelling behavior induced by alteration in granite and its implications on underground excavation

doi:10.1016/j.tust.2005.01.003

	Swelling behavior induced by alteration in granite and its implications on underground excavation
	Tu, XB ; Jian, B ; Wang, SJ ; Bian, HY ; Wang, J ; Li, SG
刊名	TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
	2005-07-01
卷号	20 期号:4 页码:378-389
关键词	Swell Alteration Granite Hydrothermal Alteration Montmorillonite Deformation Modulus Shear Strength
ISSN号	0886-7798
DOI	10.1016/j.tust.2005.01.003
文献子类	Article
英文摘要	Granite is commonly recognized as an ideal medium for underground construction. However. in the site investigation for Heimifeng Pumped Storage Power Station project, it was found that there are swelling behaviors induced by alteration ill granite and eventually causing slaking and disintegration of rock blocks. The Study shows that hydrothermal alteration in granite is primarily due to the intrusion of multi-phase igneous magma. The clay minerals, such as montmorillonite, chlorite, kaolinite, are the main causes for the swelling behavior of granite. In the exploratory adits, alteration wits observed to Occur mainly along faults or fractures in the rock masses and resulted in roof caving if water is present. Some of the highly altered borehole cores swell and crack within 24 h in water and eventually disintegrate completely. From the testing results oil the samples. the maximum axial free swelling strain is about 1.2%, while the maximum axial confined swelling strain is around 0.1% with swelling stress less than 25 kPa. Under free swelling tests, 80% of swelling is completed within 24 hours. Under confined swelling condition, swelling process is completed within 1 h for some samples, with 80% of maximum swelling strain finished within around 22 h for most or the samples. Contraction of samples occurs after swelling completed. The strength of granite. reflected by deformation and elastic moduli, shear strength, decreases due to alteration. The deformation and elastic moduli are even lower compared to highly weathered rock. The shear strength is between that for highly weathered and slightly weathered rocks. The swelling characteristics of the altered rock present great challenges for support or lining during construction and operation stages. Support or lining shall be in place immediately after excavation. Since the rock may swell when encountering water, the shotcrete shall be designed accordingly. During the construction of access tunnel and caverns, water shall be drained in time. Drainage directly from surface shall be avoided so as to prevent floor heave. (c) 2005 Elsevier Ltd. All rights reserved.
WOS关键词	TUNNELS ; CHINA ; ROCK ; DESIGN ; SOILS
WOS研究方向	Construction & Building Technology ; Engineering
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000229550700009
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/64771]
专题	中国科学院地质与地球物理研究所
通讯作者	Tu, XB
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Engn Geomech, Beijing 100029, Peoples R China 2.China Hydropower Engn Consulting Grp Corp, Cent S Design & Res Inst, Hydroelect Projects, Changsha 410014, Peoples R China 3.Nanyang Technol Univ, Underground Technol & Rock Engn Program, Protect Technol Res Ctr, Singapore 639798, Singapore 4.Nanyang Technol Univ, Sch Civil & Environm Engn, Singapore 639798, Singapore
推荐引用方式 GB/T 7714	Tu, XB,Jian, B,Wang, SJ,et al. Swelling behavior induced by alteration in granite and its implications on underground excavation[J]. TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY,2005,20(4):378-389.
APA	Tu, XB,Jian, B,Wang, SJ,Bian, HY,Wang, J,&Li, SG.(2005).Swelling behavior induced by alteration in granite and its implications on underground excavation.TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY,20(4),378-389.
MLA	Tu, XB,et al."Swelling behavior induced by alteration in granite and its implications on underground excavation".TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 20.4(2005):378-389.