Soil Moisture Prediction During Freeze and Thaw Using a Coupled Heat and Moisture Flow Model

• Main Authors: Bigi, Susan R., Shoop, Sally A.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1994
• Subjects: Soil Mechanics; Snow; Ice and Permafrost; *SOIL MECHANICS; *MOISTURE CONTENT; *FROZEN SOILS; *FROST HEAVE; HEAT TRANSFER; COMPUTERIZED SIMULATION; PERMEABILITY; PAVEMENTS; SAND; SATURATED SOILS; FREEZING; ICE; FROST; THAWING; PORE PRESSURE; SOIL STRUCTURE INTERACTIONS; WATER TABLE; HEAD(FLUID MECHANICS); *HYDRAULIC CONDUCTIVITY; FROSTB COMPUTER PROGRAM; FREEZE THAW CYCLES; SILTY SAND; UNSATURATED SOILS; PE63734A; Table Head; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA289343; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA289343

A coupled heat flow and moisture flow model (FROSTB) was used to simulate large scale freeze-thaw experiments to assess its ability to predict soil moisture conditions during freeze and thaw. The experimental data consists of temperature and soil moisture profiles through freeze-thaw cycles of a 1-m layer of frost-susceptible silty sand over roughly 2 m of gravely sand. Two experimental conditions were modeled: (1) where the soil moisture was lower than specific retention (less than 12% by weight) and no water table was present (dry case) and (2) where the soil was fairly wet and the water table was approximately im deep (wet case). During freezing, FROSTB tends to predict ice contents higher than those observed, which causes the simulated soil column to thaw slower. During thawing the predicted moisture contents in the thawed soil were close to the measured values for the wet case but were always higher than the measured moisture contents for the dry case. Possible reasons for the discrepancy are discussed.