کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6426927 1634459 2014 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Freezing and thawing characteristics of frozen soils: Bound water content and hysteresis phenomenon
ترجمه فارسی عنوان
ویژگی های انجماد و انجماد خاک های یخ زده: میزان آب و محتوای هیدرولیکی
کلمات کلیدی
خاک منجمد، هیسترزیس، رزونانس مغناطیسی هسته ای، محتوای آب محدود، اثر جذب، اثر کاپیلاری،
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
چکیده انگلیسی


- A NMR-based method is proposed for determining the bound water content in soils.
- Freezing/thawing hysteresis is characterized and possible mechanisms for the hysteresis are identified.
- Unfrozen pore water content is calculated for soils in freezing/thawing cycles.

The freezing/thawing characteristics of three soils with different compositions are investigated based on the nuclear magnetic resonance (NMR) proton spin spin relaxation time (T2) distribution and free-induction decay (FID) measurements. A threshold value of T2 is identified for defining the bound water, and the bound water contents in the soils are calculated. It is demonstrated that the bound water content varies insignificantly with temperature in all the tested soils. The hysteretic characteristics of soils are analyzed during a freezing/thawing cycle, and possible mechanisms for the hysteresis are discussed. It is found that the hysteresis loop can be divided into three distinct zones, in which the hysteresis can be accounted for by metastable nucleation, capillary and adsorption effects, and adsorption effect, respectively. A NMR-based procedure is proposed for determining the unfrozen pore water content. In particular, it is shown that the thickness of the water films decreases with the temperature in the fully-saturated frozen soils.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cold Regions Science and Technology - Volume 103, July 2014, Pages 74-81
نویسندگان
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