速度倒数方法在不同运动形式滑坡中的应用

在滑坡的时间预测领域近年来提出了很多模型和方法，如灰色系统、神经网络、灾变论、时间序列等，但速度倒数方法仍以其简单、直观、有效而在滑坡失稳预测中广泛应用。根据统计国内外滑坡加速破坏阶段的时序曲线，发现了滑坡进入加速阶段后所呈现出的4种不同的运动形式：直线型、波动型、渐进型和瞬间型，并分析了4种不同类型的运动特征和力学机制。以实例说明了速度倒数方法适用于直线型和波动型的运动形式，其力学机制是伴随着裂纹扩展的脆性破坏，可以用曲线拟合方法预测滑坡失稳； 而对于渐进型和瞬间型运动形式，由于塑性破坏的渐进性和瞬间破坏的突发性，这种方法不能满足这两种类型的预测，但仍可以直观地反映其变化趋势。

APPLICATION OF THE INVERSE-VELOCITY METHOD IN DIFFERENT MOVEMENT PATTERNS OF LANDSLIDE

Although many models are proposed in landslide prediction in recently years, such as grey system, artificial neural net and time series analysis, the inverse-velocity method is still widely used and characterized by availability and simpleness. According to the movement histories of many landslides that occurred in a variety of materials in a range of settings, four movement patterns are observed evidently during acceleration phase：linear, fluctuant, asymptotic and instantaneous form. Deformation mechanism and movement characteristic of four movement patterns are also presented. The prediction results by the inverse-velocity method are illustrated by typical examples original from the published literature：(1)The inverse-velocity method is suitable for the linear form or fluctuant form that is associated with crack growth, and it can be used by plotting the inverse-velocity curve to predict failure time.(2)Due to ductile deformation in asymptotic form or sudden acceleration in instantaneous form, the method can not directly predict failure time in the two forms. However, the overall trend of landslide deformation is easier to interpret on the inverse-velocity plot.