滑坡的变形破坏行为与内在机理

THEORETICAL STUDIES ON PREDICTION OF LANDSLIDES USING SLOPE DEFORMATION PROCESS DATA

自20世纪60年代日本学者斋藤借助于蠕变试验成果进行滑坡预测预报以来,人们就一直不停地对斜坡变形破坏行为和滑坡预报方法进行研究和探索,先后提出了数十种滑坡预测预报模型和方法。随着滑坡变形监测实例的不断增多,其变形监测资料越来越丰富,各式各样的变形-时间曲线相继产生。斜坡变形-时间曲线的类型、特征以及形成这些变形-时间曲线的力学条件等诸多问题都是滑坡预警预报必须查明的最基本科学问题。本文通过对各类滑坡变形破坏行为和变形-时间曲线的分析总结,结合岩土体流变试验成果,根据斜坡变形-时间曲线特征,将滑坡分为稳定型、渐变型、突发型3类,并给出了产生这3类变形行为的力学条件。同时,从细观力学的角度分析认为,斜坡产生宏观变形破坏行为的主要原因是岩土体细观尺度颗粒的"流动"和"微破裂",但在不同岩性组成的斜坡和同一斜坡的不同变形阶段,"流动"和"微破裂"将分别发挥不同的作用。

Research on slope deformation and failure process and landslide prediction method has been undertaken freqeuently since Saito developed the landslide prediction and forecasting method with help of creep test in 1960s.Dozens of models and methods for landslide prediction and forecasting have been put forward.With the increasing monitoring work on slope deformation and increasing available data,many kinds of displacement-time curves have been proposed.Many problems such as the types and features of slope displacement-time curves and the mechanic conditions forming the curves must be regarded as the most basic scientific problems.Theyhave to be answered and solved when landslide early warning and prediction are being carried out.This paper summarizes the landslide deformation and failure mechanisms and their corresponding displacement-time curves.With the aid of rheological test,three types of landslide deformation and failure processes are proposed.They are thehe steady type,the gradual change type and the sudden failure type.Their corresponding mechanic conditions are also studied.In the view of micromechanics,the macro deformation and failure of a slope are mainly attributed to the flow and micro rupture of rock and soil in microscopic scale.The flow and micro rupture can play different roles in slopes with different lithology or in different deformation phases of a slope.