Aging Effect on the S-p relationship due to repeated drying/wetting cycles on the Subsoil

由于底土重复干/湿循环而导致的老化对 S-p 关系的影响

• 批准号: 18K04344
• 负责人: FLORES Giancarlo
• 金额: $ 2.66万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2018
• 资助国家: 日本
• 起止时间: 2018-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-18K04344/
• 关键词: Aging effect; S-p relationship; SWCC; Contaminant; Subsoil; Aging Effect; S-p Relationship

During FY2019, we continued with the analysis of the changes in the S-p (SWCC) curve of water and an LNAPL (low viscosity paraffin liquid) when subject to repeated water table fluctuations, and participated of some scientific events where we discussed and confirmed some of our findings. Some new ideas were shared for a possible future continuation of this work.As I have left Japan, though, I have to forfeit the remaining of this grant, but the students with whom I worked at Kyoto University will partly continue with this work as part of their research work. This means that, hopefully, part of the remaining objectives of this study can be reached. They will probably be reduced though. In any case, we could work on confirming the following:1. The entry pressure of air-water system is higher than that of air-NAPL system, due to interfacial forces.2. As the changes in residual saturation reduce over time, the largest variations can be find at the beginning of the first drainage cycle, and they seem to follow a decay curve (found previously to be close to Srf(N) = (1 - Srf*) exp(-b N) + Srf*, where Srf* is the final value of residual saturation for the sample, N is the number of cycles, and b is a scaling parameter related to the easiness in reaching stability).3. Irreducible saturation was found to be correlated to initial void ratio and type of fluid.4. The final value of residual saturation is higher in air-NAPL systems than on air-water ones, most probably due to interfacial tension forces.

于2019财政年度，我们继续分析水及LNAPL（低粘度石蜡液体）的S-p（SWCC）曲线在地下水位反复波动下的变化，并参与一些科学活动，讨论及确认我们的部分发现。虽然由于我已经离开日本，我不得不放弃剩余的奖学金，但我在京都大学的学生们将继续把这项工作作为他们研究工作的一部分。这意味着，本研究的其余目标有望实现。但可能会减少。在任何情况下，我们可以确认以下几点：1.由于界面力的作用，空气-水体系的入口压力比空气-NAPL体系的入口压力高.由于残余饱和度的变化随时间减小，在第一个排水周期开始时可以发现最大变化，并且它们似乎遵循衰减曲线（以前发现接近Srf（N）=（1 - Srf*）exp（-B N）+ Srf*，其中Srf* 是样本的残余饱和度的最终值，N是循环数，以及B是与达到稳定性的容易性相关的缩放参数）。束缚饱和度与初始孔隙比和流体类型有关.空气-NAPL系统中的残余饱和度的最终值比空气-水系统中的残余饱和度的最终值高，最可能是由于界面张力。

项目成果

Variability of S-p relation of LNAPL and water under repeated drainage and imbibition

反复排水和吸吸作用下LNAPL与水S-p关系的变化

• 发表时间: 2018
• 期刊: Proceedings of the Japan Society of Civil Engineers Kansai Branch Annual Scientific Lecture 2018
• 作者: Yutaro Matsuda;Giancarlo Flores;Atsushi Takai;Toru Inui;and Takeshi Katsumi
• 通讯作者: and Takeshi Katsumi

LNAPL Contamination in Subsoil--How do they behave? (And why do we care?)

地下土壤中的 LNAPL 污染——它们的表现如何？

• 发表时间: 2019
• 作者: Yutaro Matsuda;Giancarlo Flores;Atsushi Takai;Toru Inui;and Takeshi Katsumi;Giancarlo Flores
• 通讯作者: Giancarlo Flores

Effects of repeated drainage and imbibition on the contamination behavior of a LNAPL and on its S-p relation

反复排水和吸入对 LNAPL 污染行为及其 S-p 关系的影响

• 发表时间: 2019
• 期刊: Proceedings of the 7th Asia-Pacific Conference on Unsaturated Soils
• 作者: Giancarlo Flores;Yutaro Matsuda;Yoshiyuki Yamanaka;Atsushi Takai;and Takeshi Katsumi
• 通讯作者: and Takeshi Katsumi