ISSN 1000-3665 CN 11-2202/P

    反倾层状斜坡破裂面演化特征离心机模型试验与数值模拟

    Centrifuge model test and numerical simulation on evolution characteristics of fracture surface of the anti-dipped layered slope

    • 摘要: 破裂面形成演化特征是反倾层状斜坡研究的重点之一,也是稳定性评价和工程设计治理的基础。利用室内大型土工离心机,获取坡体受力和变形参数,同时结合PFC数值模拟成果,展示斜坡破裂面的形成演化过程和特征,并讨论破裂面的形成机理。结果表明:(1)首先在坡体内部产生压剪裂隙,随后向中下部扩展,坡体压剪分区;(2)裂隙向中上部发展,破裂面初步形成,深部坡体发生弯折;(3)浅层裂隙完全贯通,形成由坡顶至坡脚的完整破裂面Ⅰ,内部潜在破裂面(Ⅱ、Ⅲ)中上部近似平行坡面,下部合并后至坡脚,而稳定受压区域与弯折区分界潜在破裂面Ⅳ呈阶梯形,同时浅层存在3条次级破裂面;(4)斜坡的变形破坏由于重力作用,使得岩层差异性受力,在压剪、拉剪及弯折作用下,裂隙由预制裂隙尖端萌生、扩展,最终贯通形成破裂面。重力是内在原因,而坡体结构特征是基础条件。研究成果可以为反倾层状斜坡进一步深入研究和实践提供参考。

       

      Abstract: The formation and evolution characteristics of fracture surface is one of the key points in anti-inclined layered slope research, and it is also the basis of stability evaluation as well as engineering design and treatment. In this study, the stress and deformation parameters of the slope are obtained by using the indoor large-scale geotechnical centrifuge. At the same time, combined with the PFC numerical simulation results, the formation and evolution process and characteristics of the slope fracture surface are displayed: firstly, the compression shear crack is generated and extends to the middle and lower part of the slope, and the compression shear zone of the slope is divided; secondly, the developments of cracks toward to the middle and upper part of the slope, and with the initial formation of fracture surface, the deep slope body is bent; finally, the shallow cracks are completely connected to form a complete fracture surface Ⅰ from the top to the foot of the slope. The middle and upper parts of the internal potential fracture surface (Ⅱ, Ⅲ) are approximately parallel to the slope surface, and the lower parts are merged gradually at the foot of the slope. While the potential fracture surface Ⅳ at the boundary between the stable compression area and the bending area is stepped. At the same time, there are three secondary fracture surfaces in the shallow layer of the slope. The formation mechanism of the fracture surface is revealed that the deformation and failure of the slope causes the differential stress of the rock stratum due to the action of gravity. Under the action of compression shear, tension shear and bending, the crack initiates and expands from the tip of the prefabricated crack, and finally penetrates to form the fracture surface. Therefore, gravity is the internal reason, and the structural characteristics of slope are the basic conditions. The research results provide a basis for further research and practice of anti-inclined layered slope.

       

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