干旱区生态环境知识资源中心(Arid): Shear strength and damage characteristics of compacted expansive soil subjected to wet-dry cycles: a multi-scale study

Arid

DOI	10.1007/s12517-021-09260-z
	Shear strength and damage characteristics of compacted expansive soil subjected to wet-dry cycles: a multi-scale study
	Liu, Kuan; Ye, Wanjun; Jing, Hongjun
通讯作者	Liu, K (corresponding author), Xian Univ Sci & Technol, Sch Architecture & Civil Engn, 58 Yanta Middle Rd, Xian 710054, Shaanxi, Peoples R China.
来源期刊	ARABIAN JOURNAL OF GEOSCIENCES
ISSN	1866-7511
EISSN	1866-7538
出版年	2021
卷号	14 期号:24
英文摘要	In expansive soil regions, engineering geological disasters frequently occur in wet-dry (WD) environments, which are inseparable from the degradation of soil shear strength and structural damage. This study attempts to assess the underlying mechanisms of shear strength degradation and micro- and mesoscale damage to expansive soil under WD cycles. Recompacted specimens were subjected to several WD cycles, then triaxial shear, nuclear magnetic resonance, and scanning electron microscopy tests were performed. Moreover, the influence of the WD cycles on the shear strength of expansive soil was evaluated. The state-of-the-art image processing and analysis techniques were combined to quantitatively investigate the evolution of the soil micro- and mesostructural characteristics. The results reveal that the deterioration of soil shear strength is primarily embodied in the initial 3 WD cycles, and is mainly due to the severe loss of cohesion (about 51.69%) during this period. Soil meso-cracks were formed under the combined effects of swelling potential and tensile stress, which mainly occurred in three stages: initiation stage (1-2 cycles); propagation stage (3-4 cycles); equilibrium stable stage (5-6 cycles). Indeed, the strength and average width of cracks were increased to varying degrees, which degraded the structural integrity of the soil. In addition, the microstructure of the soil was deeply affected by WD cycles; the total volume of pores increased significantly, the particles roundness decreased marginally, and an isotropic particles orientation was achieved as a whole with local preferential orientation (depolarization). The deterioration of shear strength of the expansive soil may be attributed to alterations in humidity, which causes the clay minerals in the soil to swell and shrink repeatedly, thereby yielding the irreversible fatigue damage of microstructure and propagation of meso-cracks. This work sheds light on the properties of shear strength evolution and mechanisms of structural damage in expansive soils in semi-arid regions.
英文关键词	Expansive soil Wet-dry cycles Shear strength NMR test SEM test
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	SCI-E
WOS记录号	WOS:000730592700006
WOS关键词	PORE-SIZE DISTRIBUTION ; MECHANICAL-PROPERTIES ; CLAY ; LOESS ; BEHAVIOR ; SHRINKAGE ; STABILITY ; POROSITY ; PATTERNS ; RAINFALL
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/2XILL650/373986
作者单位	[Liu, Kuan; Ye, Wanjun; Jing, Hongjun] Xian Univ Sci & Technol, Sch Architecture & Civil Engn, 58 Yanta Middle Rd, Xian 710054, Shaanxi, Peoples R China
推荐引用方式 GB/T 7714	Liu, Kuan,Ye, Wanjun,Jing, Hongjun. Shear strength and damage characteristics of compacted expansive soil subjected to wet-dry cycles: a multi-scale study[J],2021,14(24).
APA	Liu, Kuan,Ye, Wanjun,&Jing, Hongjun.(2021).Shear strength and damage characteristics of compacted expansive soil subjected to wet-dry cycles: a multi-scale study.ARABIAN JOURNAL OF GEOSCIENCES,14(24).
MLA	Liu, Kuan,et al."Shear strength and damage characteristics of compacted expansive soil subjected to wet-dry cycles: a multi-scale study".ARABIAN JOURNAL OF GEOSCIENCES 14.24(2021).