Shrinkage and desaturation properties during desiccation of reconstituted cohesive soil
Shrinkage and desaturation properties during desiccation of reconstituted cohesive soil
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DOI：
10.1016/j.sandf.2012.12.003
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发表时间：
2013-02
影响因子：
3.7
通讯作者：
T. Umezaki;T. Kawamura
中科院分区：
文献类型：
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作者：
T. Umezaki;T. Kawamura
作者提出了一种比空气干燥更快地降低含水量的真空蒸发方法，应用于六个饱和重塑粘性土样品，以研究干燥过程中的收缩和去饱和特性。试验条件为：真空压力pv =−93.9 ~ −97.5 kPa，固结压力σv=68.6 ~ 392 kPa，初始含水量w 0 =0.59- 0.92 wL，试样初始表面积As 0 =20-205 cm 2，其中wL为液限。在这些限制条件下得到的结果如下。土壤中孔隙水的真空蒸发发生在高于约-93 kPa的真空压力下（|PV|>93 kPa），但蒸发过程非常缓慢。在真空压力作用下，土体在无收缩阶段的最小孔隙比Emin为一常数。得到了m_（min）= 1.15和w_（s）= 87（min/Gs）的关系式，其中m_（min）=对应于收缩极限的孔隙比w_s，g_（s）=土颗粒的比重。使用真空蒸发方法，w −e、w−V/V0和w − S的连续关系比用空气干燥的常规方法更容易和更快速地获得。这三个关系式是用两个参数来表示的，即，一个是用真空蒸发试验简单地获得的实验参数，另一个是可以容易地假定和确定的参数。这三种关系式与实验结果吻合较好。此外，如果已经获得基本物理参数ws，则可以粗略地估计这三个关系，而无需进行任何测试。
A vacuum evaporation method, proposed by the authors to reduce the water content more quickly than by air drying, was applied to six saturated reconstituted cohesive soil samples to investigate shrinkage and desaturation properties during desiccation. The test conditions were a vacuum pressure ofpv=−93.9 to −97.5 kPa, a consolidation pressure ofσv=68.6–392 kPa, an initial water content ofw0=0.59–0.92wL, and an initial surface area of the specimen ofAs0=20–205 cm2, wherewLis the liquid limit. The results obtained for these restricted conditions are as follows. The vacuum evaporation of pore water from the soil occurs at a vacuum pressure higher than about −93 kPa (|pv|>93 kPa), but the evaporation process is very slow. The minimum void ratio,emin, at theno-shrinkage phase of the soil subjected to the vacuum pressure, becomes a constant value. The relationsemin≈1.15esandws≈87(emin/Gs) are obtained, whereesis the void ratio corresponding to the shrinkage limit,ws, andGsis the specific gravity of the soil particles. Using the vacuum evaporation method, the continuous relations forw−e,w−V/V0, andw−Srare more easily and more rapidly obtainable than with the conventional method by air drying. These three relations were formulated using two parameters, namely, an experimental parameter that is simply obtained using vacuum evaporation tests and a parameter that can be assumed and determined easily. The three formulated relations show a good agreement with the experimentally obtained results. Furthermore, if the basic physical parameter,ws, has already been obtained, then the three relations can be estimated roughly without the performance of any tests.