谢小帅, 陈华松, 肖欣宏, 王静, 周家文. 2019: 水岩耦合下的红层软岩微观结构特征与软化机制研究. 工程地质学报, 27(5): 966-972. DOI: 10.13544/j.cnki.jeg.2019028
    引用本文: 谢小帅, 陈华松, 肖欣宏, 王静, 周家文. 2019: 水岩耦合下的红层软岩微观结构特征与软化机制研究. 工程地质学报, 27(5): 966-972. DOI: 10.13544/j.cnki.jeg.2019028
    XIE Xiaoshuai, CHEN Huasong, XIAO Xinhong, WANG Jing, ZHOU Jiawen. 2019: MICRO-STRUCTURAL CHARACTERISTICS AND SOFTENING MECHANISM OF RED-BED SOFT ROCK UNDER WATER-ROCK INTERACTION CONDITION. JOURNAL OF ENGINEERING GEOLOGY, 27(5): 966-972. DOI: 10.13544/j.cnki.jeg.2019028
    Citation: XIE Xiaoshuai, CHEN Huasong, XIAO Xinhong, WANG Jing, ZHOU Jiawen. 2019: MICRO-STRUCTURAL CHARACTERISTICS AND SOFTENING MECHANISM OF RED-BED SOFT ROCK UNDER WATER-ROCK INTERACTION CONDITION. JOURNAL OF ENGINEERING GEOLOGY, 27(5): 966-972. DOI: 10.13544/j.cnki.jeg.2019028

    水岩耦合下的红层软岩微观结构特征与软化机制研究

    MICRO-STRUCTURAL CHARACTERISTICS AND SOFTENING MECHANISM OF RED-BED SOFT ROCK UNDER WATER-ROCK INTERACTION CONDITION

    • 摘要: 水岩长期作用下红层软岩体现出成岩作用差、易风化、易软化崩解等特点,给软岩工程设计与施工带来挑战。以滇中红层软岩地区所取泥岩试样为研究对象,首先对自然和饱水状态下岩样进行单轴和三轴压缩试验,分析水岩作用下软岩的力学特性;然后采用X射线衍射技术对不同含水状态下软岩微观结构进行对比研究;最后基于试验结果对滇中地区红层软岩遇水软化机制进行了探讨。研究结果表明:水岩作用下软岩力学性质劣化明显,岩石峰值抗压强度显著降低,岩体破坏程度提高;软岩黏土矿物颗粒吸水膨胀,微观结构由致密的团粒状转变为疏松多孔的不规则片状和鳞片状结构;伊利石等黏土矿物与水反应,产生的不均匀应力和大量微孔隙导致软岩内部结构破坏;红层软岩的遇水软化机制包括软岩矿物的溶蚀和次生作用、黏土矿物的吸水膨胀与崩解、软岩与水作用导致颗粒间胶结连结破坏等。

       

      Abstract: Under the long-term of water-rock interaction, the red-bed soft rock shows the characteristics of poor diagenesis, easy weathering and softening, which brings challenges to the soft rock engineering design and construction. Firstly, in order to analyze the mechanical properties of soft rock, uniaxial and triaxial compression tests are carried out on the samples of mudstone taken from the red-bed soft rock area of central Yunnan in the natural state and saturated state. Then the microstructure of soft rock in different water-bearing states is studied by X-ray diffraction. Finally, based on the experimental results, the softening mechanism is discussed. The results show that the mechanical properties of soft rock are obviously deteriorated under the action of hydro-rock, and the compressive strength of rock peak value is significantly reduced, the failure degree of rock mass increases. When the soft rock clay minerals absorb water, the microstructure changes from compact granular structure to loose and porous irregular flake structure. Clay mineral particles such as illite react with water, resulting in uneven stress and a large number of micropores, which causes the destruction of the internal structure of soft rock. The water-softening mechanism of red-bed soft rock includes the dissolution and secondary action of soft rock minerals, the water-absorbing expansion and disintegration of clay minerals, and the failure of intergranular bonding caused by the interaction between soft rock and water.

       

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