程富阳, 黄英, 周志伟, 赵贵刚, 张浚枫. 2017: 干湿循环下饱和红土不排水三轴试验研究. 工程地质学报, 25(4): 1017-1026. DOI: 10.13544/j.cnki.jeg.2017.04.016
    引用本文: 程富阳, 黄英, 周志伟, 赵贵刚, 张浚枫. 2017: 干湿循环下饱和红土不排水三轴试验研究. 工程地质学报, 25(4): 1017-1026. DOI: 10.13544/j.cnki.jeg.2017.04.016
    CHENG Fuyang, HUANG Ying, ZHOU Zhiwei, ZHAO Guigang, ZHANG Junfeng. 2017: UNDRAINED TRIAXIAL TEST OF SATURATED LATERITE UNDER DRYING-WETTING CYCLE. JOURNAL OF ENGINEERING GEOLOGY, 25(4): 1017-1026. DOI: 10.13544/j.cnki.jeg.2017.04.016
    Citation: CHENG Fuyang, HUANG Ying, ZHOU Zhiwei, ZHAO Guigang, ZHANG Junfeng. 2017: UNDRAINED TRIAXIAL TEST OF SATURATED LATERITE UNDER DRYING-WETTING CYCLE. JOURNAL OF ENGINEERING GEOLOGY, 25(4): 1017-1026. DOI: 10.13544/j.cnki.jeg.2017.04.016

    干湿循环下饱和红土不排水三轴试验研究

    UNDRAINED TRIAXIAL TEST OF SATURATED LATERITE UNDER DRYING-WETTING CYCLE

    • 摘要: 以云南红土为研究对象,考虑干湿循环次数、干湿循环幅度等影响因素,利用TSZ-2型全自动三轴仪,开展干湿循环下饱和红土的不排水三轴试验,研究干湿循环作用对饱和红土剪切特性的影响。试验结果表明:不固结不排水条件下,随干湿循环次数增加和干湿循环幅度增大,饱和红土的应变软化现象增强,应力-应变曲线的初始斜率、孔压峰值增大,剪切峰值、峰值轴向应变、黏聚力、内摩擦角减小;干湿循环次数的影响大于干湿循环幅度的影响。干湿循环下饱和红土剪切特性变化的实质在于红土与水之间的相互作用,包括脱湿过程中水的逃逸作用、红土颗粒的吸附作用、红土体的硬化作用及收缩作用和吸湿过程中水的楔入作用、润滑作用、软化作用及红土体的膨胀作用,干湿循环过程中上述作用不断加深加剧,严重损伤了红土体的微结构,最终改变了饱和红土的不排水剪切特性。

       

      Abstract: The influence of drying-wetting cycle to the shear characteristic of saturated laterite is studied in this paper. Undrained triaxial tests of Yunnan laterite at drying-wetting cycle are performed using type TSZ-2 full automatic triaxial test apparatus. It considers drying-wetting cycle number and drying-wetting cycle amplitude. The results show that as the drying-wetting cycle number and the drying-wetting cycle amplitude increase, the strain-softening phenomenon of saturated laterite generally enhances, the initial slope of stress-strain curve and pore water pressure peak increase, the peak shear strength and its corresponding axial strain, cohesion, internal friction angle decrease under unconsolidated undrained condition. The influence of drying-wetting cycle number is more obvious than that of its amplitude. Interaction between laterite and water is the essence of the change of shear characteristic of saturated laterite at drying-wetting cycle. They include the escape of water, the adsorption of laterite particles, hardening and shrinkage of laterite under the condition of dehydration and the wedging, lubricating, softening of water, expansion of laterite in the process of moistening. The deepening and intensifying of above actions at drying-wetting cycle can seriously damage the microstructure of laterite, ultimately change its shear characteristic.

       

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