堆积体滑坡内部变形与表层宏观形变特征的对应耦合关系及其应用研究

The Corresponding Coupling Relationship Between the Internal Deformation and the Macroscopic Deformation Characteristics of the Accumulation Landslide and Application

  • 摘要: 综合遥感技术可以捕捉滑坡地表变形迹象,但无法准确获得斜坡内部变形特征,从而限制了其评估当前斜坡所处阶段或滑动风险的能力。为克服这一问题,开展大型离心模型试验,利用多角度相机和图像处理技术收集堆积体斜坡地表和内部的变形数据,建立内部变形和宏观变形特征之间联系。研究结果为利用合成孔径雷达和激光雷达等技术进行早期滑坡识别提供了一个半定量框架。研究表明: 1)滑坡后缘的裂缝水平延伸,形成出现近似平行于坡体走向的弧形拉裂缝的发展趋势;堆积体滑坡破坏通常始于坡顶,由后向前逐步发展。2)提出新的滑坡阶段划分方法,将位移-加速度曲线与土壤的超固结比相结合,以超固结比突变点为界,突变前为土体固结沉降阶段以及应力重分布阶段,突变后为斜坡发生破坏阶段。3)选取两个典型案例进行对比分析,证明运用模型试验结果可以提高遥感技术识别滑坡变形阶段的能力,使用堆积体滑坡内部形变与表层形变特征的对应图谱对利用遥感解译结果判释滑坡体的变形阶段有一定的指导意义。

     

    Abstract: Objectives: Integrated remote sensing technology primarily captures deformation indicators on the surface of the slope but fails to delineate the internal deformation characteristics clearly. Consequently, it can only facilitate preliminary identification without accurately determining the current stage of the slope or assessing the risk of sliding. To address these limitations, experimental research was conducted. Methods: To investigate these issues, a centrifugal model test of a large-scale accumulation landslide was performed. Deformation characteristic data for both the surface and interior of the slope were obtained through multi-angle imaging, image processing, and observational deduction. This approach established a correlation between the internal deformation and the macroscopic deformation characteristics of the accumulation landslide. The resulting data provide a semiquantitative reference framework for the early identification and warning of landslides using technologies such as aperture radar, lidar, and optical remote sensing to ascertain the deformation stage of landslides. Results: The results show that: 1) During the development of the accumulation landslide, cracks at the trailing edge extend significantly in the horizontal direction, while cracks on the back wall exhibit an arc-shaped tensile development trend, approximately parallel to the slope's alignment. Slip failure in homogeneous soil slopes typically initiates at the slope crest, with overall failure occurring as the sliding surface gradually advances from back to front. 2) A novel method for classifying landslide stages is proposed, which combines the displacementacceleration curve of the accumulation landslide with the soil's over-consolidation ratio. A sudden change in the over-consolidation ratio serves as a segmentation point, with the soil consolidation settlement stage and stress redistribution stage preceding the change, and the slope failure stage following it. Conclusions: By comparing and analyzing typical cases, the results indicate that model test outcomes can aid remote sensing technology in distinguishing the deformation stages of landslides for early identification. This suggests that utilizing the correspondence mapping between the internal deformation of the accumulation landslide and the surface deformation characteristics offers valuable guidance for interpreting the deformation stage of the landslide through remote sensing.

     

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