干旱区生态环境知识资源中心(Arid): The Compression Behavior of Undisturbed and Compacted Loess Under the Controlling of Total Suction and Injected Solutions

Arid

DOI	10.3389/feart.2022.818919
	The Compression Behavior of Undisturbed and Compacted Loess Under the Controlling of Total Suction and Injected Solutions
	Zhang, Tongwei; Hu, Zhengjin; Lan, Hengxing; Deng, Yongfeng; Zhang, Huyuan
通讯作者	Zhang, TW
来源期刊	FRONTIERS IN EARTH SCIENCE
EISSN	2296-6463
出版年	2022
卷号	10
英文摘要	Thousands of square kilometers of habitable land have been created on the Loess Plateau in China. In arid and semi-arid area of Northwest China, the mechanical behavior of structural loess is sensitive to water intrusion and human engineering activities. Meanwhile, the higher water salinity in loess and seasonal variation of ambient humidity are common in this area. Due to different physical and mechanical properties of natural and compacted loess, the impacts of ambient humidity and saline water migration on their deformation are still unclear. This paper developed an oedometer test to investigate the compression behavior of natural and compacted loess under environmental humidity (represented by total suction psi) and injection water salinity (represented by osmotic suction psi(pi)) changing. The results showed that the void ratio variation Delta e of compacted loess (the dry density is 1.8 g/m(3)) under the impact of total suctions (from 14.01 to 146.23 MPa) and salinities of injected solution (0.17 mol/L NaCl, 0.29 mol/L Na2SO4 and distilled water) were under 0.01. The variation of void ratio for undisturbed loess increased about 8 times with 10 times decreasing of total suction, which was corresponding to the increase of relative humidity (RH). In the stage of solution injection, the deformation of undisturbed loess increased with the psi-psi(pi) increasing, and the differences between different samples reached to nearly 20 times. The mechanism was that the salt inside undisturbed loess would deliquescence when the RH was higher than DRH (Deliquescence Relative Humidity), and the natural structure collapsed. The compression index C-c of samples generally decreased with psi-psi(pi), and the compressibility of undisturbed loess was higher. The swelling indices C-s of samples slightly decreased with psi-psi(pi), but the variation was not significant. The strain-stress relationships of loess can be well described by Duncan-Chang constitutive model. Interestingly, the difference of initial deformation modulus Delta E-s of two loesses, which represented the structural compression under the coupling of total suction and osmotic suction, linearly related to the psi-psi(pi). The Delta epsilon(max) between the structural loess and compacted loess exponential increased with psi-psi(pi). In the engineering practice, the humidity and saline water intrusion should be considered in the long-term behavior of loess in shallow layer.
英文关键词	compression behavior undisturbed loess compacted loess total suction injection solutions
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000764148800001
WOS关键词	SOIL ; SALINITY ; STRESS
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/376289
推荐引用方式 GB/T 7714	Zhang, Tongwei,Hu, Zhengjin,Lan, Hengxing,et al. The Compression Behavior of Undisturbed and Compacted Loess Under the Controlling of Total Suction and Injected Solutions[J],2022,10.
APA	Zhang, Tongwei,Hu, Zhengjin,Lan, Hengxing,Deng, Yongfeng,&Zhang, Huyuan.(2022).The Compression Behavior of Undisturbed and Compacted Loess Under the Controlling of Total Suction and Injected Solutions.FRONTIERS IN EARTH SCIENCE,10.
MLA	Zhang, Tongwei,et al."The Compression Behavior of Undisturbed and Compacted Loess Under the Controlling of Total Suction and Injected Solutions".FRONTIERS IN EARTH SCIENCE 10(2022).