宋丙辉, 谌文武, 吴玮江. 2016: 兰州原状Q2黄土抗剪强度的水敏感性特征研究. 工程地质学报, 24(s1): 799-805. DOI: 10.13544/j.cnki.jeg.2016.s1.115
    引用本文: 宋丙辉, 谌文武, 吴玮江. 2016: 兰州原状Q2黄土抗剪强度的水敏感性特征研究. 工程地质学报, 24(s1): 799-805. DOI: 10.13544/j.cnki.jeg.2016.s1.115
    SONG Binghui, CHEN Wenwu, WU Weijiang. 2016: STUDY ON THE WATER SENSITIVITY CHARACTERISTICS OF THE SHEAR STRENGTH OF UNDISTURBED Q2 LOESS IN LANZHOU. JOURNAL OF ENGINEERING GEOLOGY, 24(s1): 799-805. DOI: 10.13544/j.cnki.jeg.2016.s1.115
    Citation: SONG Binghui, CHEN Wenwu, WU Weijiang. 2016: STUDY ON THE WATER SENSITIVITY CHARACTERISTICS OF THE SHEAR STRENGTH OF UNDISTURBED Q2 LOESS IN LANZHOU. JOURNAL OF ENGINEERING GEOLOGY, 24(s1): 799-805. DOI: 10.13544/j.cnki.jeg.2016.s1.115

    兰州原状Q2黄土抗剪强度的水敏感性特征研究

    STUDY ON THE WATER SENSITIVITY CHARACTERISTICS OF THE SHEAR STRENGTH OF UNDISTURBED Q2 LOESS IN LANZHOU

    • 摘要: 黄土是世界公认的特殊性问题土。结构性黄土具有显著的水敏感性特征,黄土地区遇到的各种工程问题多和其密切相关。本文通过不同含水量原状Q2黄土的室内直剪试验研究了黄土抗剪强度的水敏感性特征,从定量的角度探讨了峰值抗剪强度、残余抗剪强度、最终残余抗剪强度和土体结构强度等强度参量与含水量和法向压力间的相关关系,研究结果表明:原状Q2黄土峰值强度的水敏感性强于残余强度和最终残余强度的水敏感性,指数函数和线性函数可以分别用来描述峰值强度以及残余强度和最终残余强度与含水量间的相关关系。不同法向压力下原状Q2黄土的峰值强度与含水量间相关关系可以进行归一化处理,指数函数能够用来描述这种归一化关系。结构强度和含水量之间也存在指数函数形式的定量关系。由于具有较高的结构强度,不同法向压力下原状Q2黄土的破坏剪应变多位于1%~2%之间。本文的研究成果对于进一步理解和认知非饱和结构性黄土抗剪强度的发挥机制及其抗剪强度设计准则均具有一定的借鉴意义。

       

      Abstract: Loess was seen as a kind of unique problematic soil around the world. Structural loess always embodies some very high water sensitivities which correlate closely with common engineering problems exiting in loess area. In this paper, a series of direct shear tests were utilized to study the relationships between peak strength, residual strength, ultimate strength, structural strength and water content and normal pressure for undisturbed Q2 loess with different moistures quantitatively. It could be concluded that peak strength of loess has the higher water sensitivity than its' residual and ultimate strength, and exponential function and linear function could be used to depict the relations between peak strength and water content and the relations between residual/ultimate strength and water content, respectively. The relationships between peak strength and water content can be normalized with respect to the maximal peak strength under various normal pressures, and exponential function is suited to describe the normalized relationships. In addition, there is an exponential correlation existing between structural strength and water content. For undisturbed Q2 loess, the shear strains under different normal pressures at failure are in the area of 1%~2% due to its' strong structural strength. Research findings obtained in the paper will be useful in the further comprehension and cognizance on the functioning mechanism and design criteria of shear strength of unsaturated structural loess.

       

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