反复干湿循环对重塑非饱和黄土力学特性影响

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Abstract Research purposes:Under the action of the repeated cycles of rainfall and evaporation, the water and gas state in shallow layers are in dynamic variation, which will have an irreversible effect on the mechanical properties of soil. In this paper, the SWCC curve test and triaxial test of remolded unsaturated loess after different times of dry-wet cycle were carried out. The effects of dry-wet cycle on water-holding capacity, strength and deformation characteristics of unsaturated loess were studied.
Research conclusions:(1) There is an obvious hysteretic phenomenon for the soil-water characteristic curve of unsaturated loess, which is gradually diminished with the increase of the times of dry-wet cycle. (2) The more suitable SWCC empirical model for unsaturated loess is VG model, and then the SWCC prediction models for loess under different dry-wet cycle times are established based on the VG model. (3) The stress-strain curve profiles are transformed from the strain hardening type to the strain softening type due to wet-dry cycle, the initial shear stiffness after wet-dry cycle is larger than that of the initial specimens, nevertheless, the failure strength is smaller. (4) With the increase of dry-wet cycle times, the effective cohesion c′,effective friction angle φ′and the suction friction angle φ^b of unsaturated loess are all decreased gradually. By comparison, the dry-wet cycle has the most effect on the effective cohesion, followed by effective friction angle, and the suction angle is affected least. (5) The research results can provide a reference for the selection of strength parameters in slope engineering design and reinforcement in loess area.

Key words： unsaturated loess drying-wetting cycles soil-water characteristics curve(SWCC) strength properties prediction model

Received: 01 February 2021

PACS:

TU411.3

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	Articles by authors
	MA Xuening
	ZHANG Yuqin
	ZHANG Peiyun
	WANG Xu

Cite this article:

MA Xuening,ZHANG Yuqin,ZHANG Peiyun, et al. Experimental Research on the Effect of Repeated Drying-wetting Cycles on the Mechanical Properties of Remolded Unsaturated Loess[J]. Journal of Railway Engineering Society, 2022, 39(1): 1-6.

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https://tdgcxb.crec.cn/EN/ OR https://tdgcxb.crec.cn/EN/Y2022/V39/I1/1

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