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从陕西泾阳泾河南塬11个新近发生和临滑的黄土滑坡不同深度位置采取原状土样,根据滑坡所处的地质环境和灌溉水诱发条件,按不同应力水平和不同含水率情况,分别对滑带黄土和古土壤进行了三轴蠕变实验和直剪蠕变实验,获得了该类滑带土的蠕变特性:蠕变形变均包含等速蠕变、加速蠕变和蠕变破坏3个阶段,但从加速蠕变到蠕变破坏均历时短暂;滑带土均表现为塑性破坏特征;滑带土发生蠕变破坏时对应的应变量ε基本在10%以下,随着含水率的增加,蠕变破坏相应的应变量也随之降低;而直剪蠕变在不同含水率下的破坏应变量都在4%以内;历时(t>0 min)的应力–应变等时曲线族几乎为一束曲线簇,均具有“归一化”现象,反映出该区滑带土具有良好的一致的蠕变变形特性。讨论了滑带土蠕变特性与边坡失稳时间预报模型之间的内在联系,为黄土滑坡的临滑预报作了实验研究和理论探讨。
Based on the geological conditions of the landslide and the induced conditions of irrigation water, 11 newly occurring loess landslides at the Jinghe South Plateau in Jingyang, Shaanxi Province were taken at different depths. According to the different stress levels and different water cut rates, Three-axis creep experiment and direct shear creep experiment with loess and paleosol were carried out to obtain the creep characteristics of this kind of slippery zone soil. Creep deformation included three kinds of constant velocity creep, accelerated creep and creep damage Stage, but from the accelerated creep to creep rupture both lasted for a short time; the sliding zone soil all showed plastic failure characteristics; the corresponding strain ε in the creep failure zone of slip zone soil was below 10% basically. With the increase of moisture content , The strain amount corresponding to creep failure also decreases. However, the shear strain of straight shear creep under different water cut rates is less than 4%. The stress-strain isochronal curves over time (t> 0 min) A cluster of curves all have the phenomenon of “normalization ”, which shows that the sliding zone soil has a good consistent creep deformation characteristics. The intrinsic relationship between the creep behavior of sliding zone soil and the prediction model of slope instability is discussed. The experimental study and theoretical discussion are made for the prediction of the slip of loess landslide.