Development of simple and compact in-situ testing system measurement in unsaturated soils

开发简单紧凑的非饱和土原位测试系统测量

• 批准号: 15360253
• 负责人: TAKESHITA Yuji
• 金额: $ 6.91万
• 依托单位: Okayama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360253/
• 关键词: non destructive testing; in situ test; unsaturated soils; ground penetrating radar; permeability test; saturated-unsaturated soil hydraulic properties; 不飽和土

It is well noticed that in-situ measurement and evaluation of saturated-unsaturated soil hydraulic properties is essential to practical and accurate prediction of water movement in soil such as natural slope, embankment, landfill and agricultural field.In this research, firstly a fast, simple and nondestructive procedure to measure near-surface soil water content profiles in unsaturated sandy soils is proposed. Surface ground-penetrating radar (GPR) system is employed to estimate the average soil water content in the survey region as a function of the soil dielectric constant measured by electromagnetic wave velocities. GPR has a couple of advantages over the intrusive soil moisture sensors. GPR system offers a simple approach for in-situ determination of soil water content and a completely non-intrusive measurement. GPR may be a suitable for low-cost mapping of soil water content profiles in large sample volume.Secondly, a new field experimental method of determining field-saturated and unsaturated hydraulic conductivity continuously in the near surface of unsaturated soils is proposed. In this method, a ponded single-ring infiltrometer technique, such as the Guelph Pressure Infiltrometer (GPI) method has been investigated based on the field and numerical experiments in our study. The GPI method is performed to determine the field-saturated hydraulic conductivity. The instantaneous profile method with the unit gradient assumption was applied to determine unsaturated hydraulic conductivity as a function of volumetric water content during drainage period. The vertical soil moisture profiles were measured by using a portable device for collecting soil water content information from multiple depths. The advantage of the proposed method is that it allows measurement of hydraulic conductivity of the unsaturated soils by quite simple in-situ permeability test data. The utility of our proposed method is demonstrated by using numerical models.

本文首先提出了一种快速、简便、无损的非饱和砂土近地表含水率测量方法，并对其进行了研究。地面探地雷达(GPR)系统被用来估计调查区域的平均土壤含水率，它是由电磁波速度测量的土壤介电常数的函数。与侵入式土壤水分传感器相比，探地雷达有几个优点。探地雷达系统为现场测量土壤水分提供了一种简单的方法，而且是一种完全非侵入性的测量。探地雷达可能适用于大样本量土壤水分剖面的低成本填图。其次，提出了一种在非饱和土近地表连续测定田间饱和和非饱和导水率的新的田间试验方法。在该方法中，我们在野外和数值实验的基础上，研究了一种池塘单环入渗计技术，如Guelph压力入渗计(GPI)方法。采用GPI法确定田间饱和导水率。采用单位坡度假设的瞬时剖面法，确定了排水期非饱和导水率随体积含水率的变化规律。利用便携式多深度土壤水分信息采集装置对土壤水分垂直剖面进行了测量。该方法的优点是可以通过非常简单的原位渗透试验数据来测量非饱和土的渗透系数。通过数值模型验证了该方法的有效性。

项目成果

In-situ permeability test for measuring filed-saturated and unsaturated hydraulic conductivity by using soil moisture measurements.

通过土壤湿度测量来测量现场饱和和非饱和导水率的原位渗透性测试。

• 发表时间: 2006
• 期刊: Proceedings of the 41^<th> JGS Annual Meeting (in press)
• 作者: S.Piyamahant;H.Shima;竹下祐二;Y.Takeshita
• 通讯作者: Y.Takeshita

Permeability of sand sediment soil determined by the pressure infiltrometer test.

通过压力渗透仪试验测定砂沉积土的渗透性。

• 发表时间: 2004
• 期刊: Proceedings ISC-2 on Geotechnical and Geophysical Site Characterization Vol.1
• 作者: S.Piyamahant;H.Shima;竹下祐二;Y.Takeshita;竹下祐二;竹下祐二;Y.Takeshita;Y.Takeshita;T.Morii;1竹下祐二;K.Kamiya;森井俊広;Y.Takeshita;T.Morii
• 通讯作者: T.Morii

In-situ measurement and evaluation of soil permeability in sand sediment

砂沉积物土壤渗透率的现场测量与评价

• 发表时间: 2003
• 期刊: Proceedings of the Asian Conference on Unsaturated Soils
• 作者: S.Piyamahant;H.Shima;竹下祐二;Y.Takeshita;竹下祐二;竹下祐二;Y.Takeshita;Y.Takeshita;T.Morii;1竹下祐二;K.Kamiya;森井俊広;Y.Takeshita;T.Morii;Y.Takeshita;T.Morii;K.Kamiya;T.Morii;T.Morii;竹下祐二;森井俊広;IY.Takeshita;T.Morii
• 通讯作者: T.Morii

地中レーダによる河川堤防内の水分動態の非破壊計測方法

地下雷达河堤水动力无损测量方法

• 发表时间: 2003
• 期刊: 木学会第58回年次学術講演概要集
• 作者: 奥松俊博;岡林隆敏;房前慎一;船原祐樹;大岩根健吾;竹下祐二
• 通讯作者: 竹下祐二

土の飽和・不飽和水分特性の原位置測定

土壤饱和和非饱和水分特性的现场测量

• 发表时间: 2003
• 期刊: 38回地盤工学研究発表会平成15年度発表講演集
• 作者: 奥松俊博;岡林隆敏;房前慎一;船原祐樹;大岩根健吾;竹下祐二;森井俊広
• 通讯作者: 森井俊広