Experimental Research on Strength and Microstructure Evolution of Q2Undisturbed Loess under Different Wetting-drying Cycle Paths

被引：0
|
作者：
Liu Y.-Y. [1 ]
An C. [1 ]
Lai H.-P. [2 ]
Wang G. [1 ]
Xie M.-D. [1 ]
机构：
[1] School of Civil Engineering, Chang'an University, Shaanxi, Xi'an
[2] School of Highway, Chang'an University, Shaanxi, Xi'an
来源：
Zhongguo Gonglu Xuebao/China Journal of Highway and Transport | 2022年 / 35卷 / 12期
基金：
中国博士后科学基金; 中国国家自然科学基金;
关键词：
mechanical strength; microstructure; triaxial test; tunnel engineering; undisturbed loess; wetting-drying cycle;
D O I：
10.19721/j.cnki.1001-7372.2022.12.014
中图分类号：
学科分类号：
摘要：
This paper aimed to investigate the influence of different wetting-drying cycle paths on the macro strength and microstructure of Q2undisturbed loess. Considering the environment of buried loess, the triaxial shear, nuclear magnetic resonance and scanning electron microscope were carried out under three wetting-drying cycle paths respectively. The strength and microstructure of Q2undisturbed loess, combined with the change of mineral composition, were analysed. The relationship between the strength and microstructure was discussed. Results indicate that: the macroscopic parameter-cohesion and the microscopic parameters-pore distribution, average diameter of pore and soil particles have different degrees of degradation under different cycle paths, and the trend of parameters attenuation is completely consistent, that is, the larger the range of wetting-drying cycle and the higher the upper limit water content, the more serious the parameters attenuation and the more obvious the degradation effect. The evolution characteristics of internal friction angle, pores and soil particles structure arc similar, that is, the internal friction angle fluctuates slightly, and the morphology, structural complexity and arrangement order of pores and soil particles are basically stable. Considering the wetting-drying amplitude, the upper limit water content and the number of cycles, the characteristic function of micro pore degradation was constructed to explain the degradation characteristics of pore. The two-stage development law of pore deterioration was also revealed, namely, the rising stage of wave-like damage accumulation and the stable stage of damage. These related results can provide useful guidance for understanding the macro and micro degradation of undisturbed loess under different wetting-drying cycles. © 2022 Xi'an Highway University. All rights reserved.
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页码：168 / 180
页数：12
相关论文
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