An improved specimen preparation method for marine shallow gas-bearing sand sediments and its validations

doi:10.1016/j.jrmge.2020.11.010

	An improved specimen preparation method for marine shallow gas-bearing sand sediments and its validations
	Wang, Yong 1; Kong, Lingwei 1; Wang, Min 2; Wang, Yanli 3; Cheng, Peng 4
刊名	JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
	2021-06-01
卷号	13 期号:3 页码:682-693
关键词	Shallow gas Gas-bearing sediments Bubbles Mechanical behaviour Bender element
ISSN号	1674-7755
DOI	10.1016/j.jrmge.2020.11.010
英文摘要	Instabilities of shallow gas-charged seabed are potential geological hazards in ocean engineering. In practice, the conventional field sampling techniques failed to obtain undisturbed gas-bearing sediments from the seabed for laboratory mechanical testing because of sensitive gas exsolution and escape from sediments. However, preparation of representative remoulded gas-charged specimens is a challenging issue, because it is rather difficult to quantitatively control the gas content and obtain uniform distribution of gas bubbles within the specimen. Given the above problems, this work proposes a reliable approach to reconstitute the high-saturation specimen of gas-charged sediments in the laboratory by an improved multifunction integrated triaxial apparatus (MITA). This apparatus is developed based on an advanced stress path triaxial system by introducing a temperature-controlled system and a wave-monitoring system. The temperature-controlled system is used to accurately mimic the in situ environments of sediments in the seabed. The wave-monitoring system is utilized to identify exsolution point of free gas and examine the disturbance of gas to specimens during gas exsolution. The detailed procedure of gassy specimen preparation is introduced. Then, the quality of prepared specimens using our improved apparatus is validated by the high-resolution micro-X-ray computed tomography (mu CT) scanning test, from which bubble occurrence and size distribution within the gassy sand specimen can be obtained; and preliminary mechanical tests on gassy sand specimens with various initial saturation degrees are performed. The proposed specimen preparation procedure succeeds in proving the postulated occurrence state of gas bubbles in coarse-grained sediments and accurately controlling the gas content. (C) 2021 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V.
资助项目	National Natural Science Foundation of China[51979269] ; National Natural Science Foundation of China[51579237] ; National Natural Science Foundation of China[51779017]
WOS研究方向	Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000656383700016
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/27406]
专题	中科院武汉岩土力学所
作者单位	1.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China 2.Los Alamos Natl Lab, Theoret Div, Fluid Dynam & Solid Mech, Los Alamos, NM 87545 USA 3.Minist Water Resources, Key Lab Geotech Mech & Engn, Yangtze River Sci Res Inst, Wuhan 430010, Peoples R China 4.Hunan Univ, Design Inst Co Ltd, Changsha 410082, Hunan, Peoples R China
推荐引用方式 GB/T 7714	Wang, Yong,Kong, Lingwei,Wang, Min,et al. An improved specimen preparation method for marine shallow gas-bearing sand sediments and its validations[J]. JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING,2021,13(3):682-693.
APA	Wang, Yong,Kong, Lingwei,Wang, Min,Wang, Yanli,&Cheng, Peng.(2021).An improved specimen preparation method for marine shallow gas-bearing sand sediments and its validations.JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING,13(3),682-693.
MLA	Wang, Yong,et al."An improved specimen preparation method for marine shallow gas-bearing sand sediments and its validations".JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING 13.3(2021):682-693.