Modelling seepage flow velocity in centrifuge models
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摘要: 结合黏性土的压缩特性和 Kozeny-Carman 方程,考虑离心加速度变化对土体固有渗透率的影响,推导了渗流速度和离心加速度的关系式。参考常规渗流试验装置的构造,并结合离心模型试验的特点,研制了常水头离心渗流试验装置。应用该装置针对糯扎渡高心墙堆石坝的心墙黏土,分别进行了常规渗流试验和 10 g , 20 g , 30 g 常水头离心渗流试验。试验结果表明: Ng ( N 倍重力加速度)和 1 g 条件下渗透系数的比值随离心加速度的增大逐渐减小,但变化范围不大,接近于 N 。研究结果对于深入认识离心模型试验中的渗流相似准则具有重要意义。Abstract: Based on the characteristics of clay compression and the Kozeny-Carman equation, the relation between seepage flow velocity and centrifugal accelerations is deduced considering the change of intrinsic permeability. An apparatus for constant head seepage tests is developed considering the set-up of conventional seepage test apparatus and the characteristics of centrifugal model tests. A series of seepage tests (1 g, 10 g, 20 g, 30 g) are performed on Nuozhadu core-wall clay by means of the apparatus. It is concluded that the ratio of Ng and 1 g hydraulic conductivity decreases with the increase of centrifugal acceleration, but the variation is small and the ratio is close to N. The research results are important for understanding the scaling of seepage flow velocity in centrifuge models.
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Keywords:
- centrifuge modelling /
- seepage /
- scaling law /
- hydraulic conductivity /
- intrinsic conductivity
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