On swelling behaviors of a bentonite under different water contents
On swelling behaviors of a bentonite under different water contents
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不同含水量下膨润土的膨胀行为研究
DOI：
10.1680/jgeot.21.00312
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发表时间：
2022
期刊：
影响因子：
5.8
通讯作者：
H. Komine
中科院分区：
文献类型：
--
作者：
Hailong Wang;Dachi Ito;Takumi Shirakawabe;Kunlin Ruan;H. Komine
本研究从一个问题开始：在膨胀压力试验（ps试验）中，初始含水量（wi）如何影响压实膨润土的平衡膨胀压力（peq） ？然而，基于一种膨润土Kunigel V1 （K_V1）的实验，讨论扩展到以下问题：1)对peq的影响，2)孔隙水密度（ρpw）， 3)晶体和渗透膨胀的共存，以及4)peq与压实试验（pc试验）的关系。结果表明，一般情况下，wi对peq的影响不显著，但在相对较高的wi和干密度（ρd）条件下可能会出现显著影响。在36 ~ 65%的w范围内，蒙脱土晶体溶胀（d001= 1.0 ~ 1.9 nm）和渗透性溶胀（d001≥4.0 nm）两种溶胀类型同时存在。由于K_V1的ρpw可能在1.1 ~ 1.2 Mg/m3之间，因此，当样品的最终干密度（ρdf）大于1.46 Mg/m3时，ps试验中的peq主要受结晶膨胀的影响，而当样品的最终干密度(ρdf) <1.05 Mg/m3时，peq主要受渗透膨胀的影响。结合pc测试结果，用所提出的概念模型解释了wi对peq的影响。
This study starts from a question: how would initial water content (wi) affect equilibrium swelling pressure (peq) of compacted bentonites in swelling pressure tests (ps tests)? However, discussions, based on experiments of a bentonite, Kunigel V1 (K_V1), are extended to issues: 1) wi effect on peq, 2) pore water density (ρpw), 3) co-existence of crystalline and osmotic swelling, and 4) relation between peq and compaction tests (pc tests). It is revealed that wi has insignificant effect on peq in general, though significant effect may appear for relatively high wi and dry density (ρd) conditions. Two swelling types, crystalline swelling with basal spacing of montmorillonite (d001= 1.0 nm - 1.9 nm) and osmotic swelling (d001 ≥ ∼4.0 nm), co-exist in a w range from 36 to 65%. With the fact that ρpw of K_V1 may range from 1.1 to 1.2 Mg/m3, it is expected that crystalline swelling may mainly govern peq in ps tests if the final dry density of a specimen (ρdf) is larger than 1.46 Mg/m3, while osmotic swelling may mainly govern if ρdf <1.05 Mg/m3. Together with results of pc tests, the effect of wi on peq are explained by the proposed conceptual model.