Subsurface Water Movement and Downslope Deformation in Model-Slope Tests by Artificial Rainfall
Subsurface Water Movement and Downslope Deformation in Model-Slope Tests by Artificial Rainfall
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人工降雨模型边坡试验中的地下水运动和下坡变形
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
H. Ochiai
中科院分区：
文献类型：
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作者：
Y. Okada;H. Miyajima;H. Ochiai
通过人工降雨对河沙进行准真实比例模型斜坡试验来再现滑坡，其中仔细监测了地下水运动和下坡变形。松散状态的试件（长 9.0 米，宽 1.0 米，深 0.5 米）的强度为 100 毫米/小时的降雨导致喷水开始后 2,931 秒发生破坏。首先，孔隙流体逐渐下降，导致湿润锋与基底平行，砂样容易受到垂直收缩的影响。从破坏前 300 秒开始，等位线开始正常弯曲到模型坡底，并且孔隙流体受到下坡流的影响。与此同时，深层土体应变也已开始显着。陡坡上坡部深层蠕变变形最严重，并在该段内引发破坏。在源区未观察到超孔隙水压力。而由于失效的上坡体的碰撞，产生了严重的过高压头，导致液化。这表明，滑坡的产生必须依赖于孔隙压力的动态变化，而不是在源区，而是在压缩的下斜坡部分。
The flowslide is reproduced by the quasi-real scale model-slope tests on river sand by artificial rainfall, in which subsurface water movement and downslope deformation are carefully monitored. The rainfall at the intensity of 100 mm/hour on the specimen formed at loose state (9.0-metre long, 1.0-metre wide, 0.5metre deep) have brought about the failure at 2,931 sec after the onset of sprinkling. Firstly, the pore-fluid has descended gradually leading to the parallel wetting-front to the base, and the sand specimen has been susceptible to the vertical contraction. From 300 sec before the failure, the equi-potential lines started to bend normally to the model-slope base and the pore-fluid has been subject to downslope flow. At the same time, the soil strain in deep layer has considerably started. The most severe creep deformation has been produced in the deep layer among the upper slope portion on steep slope and the failure has been initiated within this section. The excess pore-pressure has not been observed in the source area. Whereas, severe excessive pressure head has been generated due to the collision of the failed upper slope-mass, leading to liquidization. It suggests that the dependence of flowslide generation must be on the dynamic changes in pore-pressure not in the source area but in the compressed lower slope-section.