Time-Prediction Method of the Onset of a Rainfall-Induced Landslide Based on the Monitoring of Shear Strain and Pore Pressure
Time-Prediction Method of the Onset of a Rainfall-Induced Landslide Based on the Monitoring of Shear Strain and Pore Pressure
复制标题
基于剪切应变和孔隙压力监测的降雨诱发滑坡发生时间预测方法
DOI：
10.1007/978-3-319-53487-9_10
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Katsuo Sasahara
中科院分区：
文献类型：
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作者：
Katsuo Sasahara;Naoki Sakai;笹原克夫，岩田直樹;Katsuo Sasahara
模拟降雨作用下边坡的剪切变形对预测滑坡的发生具有重要意义。通过对人工降雨条件下桑迪边坡模型的变形和土水特征监测，建立了降雨入渗引起边坡剪切变形和滑坡发生的预测方法。通过对实测数据的分析，确定了同一深度剪应变与孔压之间的双曲线关系。基于此关系，建立了边坡剪应变的时间预测方法。首先对边坡破坏前任意时刻的剪应变-孔压关系和时间-孔压关系进行了回归分析。将这两个方程结合起来，就得到了时间和剪切应变之间的关系方程。该方程较好地模拟了边坡剪应变随时间的变化。然后，通过对时间与剪切应变之间的关系的方程进行微分，导出时间与剪切应变速度的倒数之间的关系的方程。这种时间预测方法预测的破坏时间相对较好，特别是在较深的土层中的边坡时，剪切变形进行的正孔压的平稳增加。剪应变不能跟随孔压的快速上升。结果表明，该方法可用于预测边坡剪切变形的时间变化和边坡的破坏时间。
It is important to simulate the shear deformation of a slope under rainfall to predict the onset of rainfall-induced landslides. Monitoring of deformation and soil–water characteristics in a sandy slope model under artificial rainfall was conducted to establish a prediction method for shear deformation of the slope due to rainfall infiltration and the onset of a rainfall-induced landslide. A hyperbolic relationship between the shear strain and the pore pressure at the same depth was identified from the analysis of the monitored data. A time-prediction method of the shear strain in the slope was established based on the relation as follows. Regression analyses of the shear strain—the pore pressure relationship at any given time before the failure of the slope—and the time—the pore pressure relationship at the same time—were conducted first. Combining both equations produced an equation for the relationship between the time and the shear strain. The equation simulated the time variation of shear strain in the slope relatively well. Then, an equation for the relationship between the time and the inverse of the shear strain velocity was derived by differentiating the equation for the relationship between the time and the shear strain. This time-prediction method predicts the failure time relatively well, especially at deeper soil layers in the slope when the shear deformation proceeds with the smooth increase of positive pore pressure. The shear strain cannot follow rapid jumping up of the pore pressure. The results showed that the procedure described above could be applicable for the prediction of the time variation of shear deformation and the failure time of the slope.