大型基岩顺层滑坡滑带形成演化过程与模式

大型基岩顺层滑坡是对人民生命财产及国家重要基础设施安全危害较为严重的滑坡类型,滑带的性质对于这类滑坡具有控制作用,大型基岩顺层滑坡滑带形成演化过程与模式成为这类滑坡研究的重要科学问题。以三峡库区为例,在分析基岩顺层滑坡分布与滑带发育特征的基础上,将滑带形成演化过程划分为3个阶段:原生软岩、层间剪切带和滑带;通过滑带形成过程中原生软岩、层间剪切带和滑带的性质对比,研究滑带形成过程中的物理性质、岩石矿物组成和含量、微结构和连接特征、矿物微观演变、物理化学性质和物理力学性质的演化过程,最后总结得出滑带形成演化模式。

EVOLUTION PROCESS AND PATTERN OF SLIDING ZONE IN LARGE CONSEQUENT BEDDING ROCK LANDSLIDE

Large consequent bedding rock landslide is one of the most serious geological disasters.The evolution of landslide is controlled by the characters of sliding zone.And then,evolution process and pattern of sliding zone in the landslide become the key scientific questions.Firstly,the distribution and sliding zone development of large consequent bedding rock landslides in the Three Gorges Reservoir area are analyzed.Secondly,the evolution process of sliding zone of the landslide is divided into three stages,i.e.original soft rock,interbedded shear zone and sliding zone.Thirdly,the evolution of sliding zone characters is studied by comparing the characters in the three stages.By field investigation,grain test,X-ray diffraction(XRD),differential thermal analysis(DTA),scanning electronic microscope and energy dispersive X-ray(SEM-EDX),physicochemical test and physico-mechanical test,the physical property,clay mineral component and content,microstructure and contact feature,physicochemical property and physico-mechanical property are systemically studied.Finally,the evolution pattern of sliding zone in large consequent bedding rock landslide is shown.The following conclusions can be drawn in the evolution of sliding zone.(1)The grains size become finer.(2)The content of clay mine rises,the interbedded shear zone is montmorillonitization;and the sliding zone is illitization and kaolinitization.(3)The microstructural character of interbedded shear zone is most unfavorable.(4)The physicochemical and physico-mechanical characters of the intebedded shear zone are most unfavorable.(5)The characters of the interbedded shear zone are most unfavorable;and the landslide with interbedded shear zone should be paid more attentions to.