Field frost heave measurement and prediction during periods of seasonal frost

1990 ◽  
Vol 27 (3) ◽  
pp. 393-397 ◽  
Author(s):  
H. N. Hayhoe ◽  
D. Balchin
Keyword(s):  
Temperature Gradient ◽  
Displacement Transducer ◽  
Linear Displacement ◽  
Time Domain Reflectometry ◽  
Frost Heave ◽  
Unfrozen Water ◽  
Data Logger ◽  
Unfrozen Water Content ◽  
Frost Penetration ◽  
Displacement Transducers

Frost heave measurements were taken over two winter seasons on a clay loam soil located near Ottawa, Canada. Heaving was measured using linear displacement transducers attached to a metal frame that was anchored in the soil below the depth of frost penetration. The output of the displacement transducer was recorded hourly using a microcomputer-based data logger. The system functioned reliably and the observed data compared well with published measurements.Soil temperature was recorded simultaneously using thermocouples. Time-domain reflectometry was used to measure the unfrozen water content. The study shows that soil temperature measurements can be used to estimate the temperature gradient at the freezing front for determining the cumulative frost heave, as suggested by the Konrad–Morgenstern theory of ice segregation processes. Key words: frost heave, temperature, gradient, displacement transducer, segregational potential.

The measurement of unfrozen water content by time domain reflectometry: results from laboratory tests

1981 ◽  
Vol 18 (1) ◽  
pp. 131-144 ◽  
Author(s):  
D. E. Patterson ◽  
M. W. Smith
Keyword(s):  
Dielectric Property ◽  
Water Content ◽  
Time Domain ◽  
Empirical Relationship ◽  
Time Domain Reflectometry ◽  
Unfrozen Water ◽  
Published Data ◽  
Frozen Soils ◽  
Unfrozen Water Content ◽  
Property Versus

A new technique for determining the volumetric unfrozen water content of frozen soils is reported, which uses time domain reflectometry (TDR) to measure the dielectric property. Using precise temperature control, the technique, which was developed previously by others for unfrozen soils, has been successfully applied to the measurement of unfrozen water contents of frozen soils. Curves of the dielectric property versus temperature show a close similarity to unfrozen water content curves, for a variety of soils. Results from experiments on ice–water mixtures and from combined TDR–dilatometry experiments on frozen soils suggest that an empirical relationship obtained by Topp, Davis, and Annan may be applicable to frozen media as well as unfrozen soils. Using this relationship, dielectric values were converted to unfrozen water content values, and the results agreed very closely with published data for similar soils, determined by other methods. For silt loams, agreement is typically within ± 1½% in volumetric water content, and for clays ± 3 %. Some of this difference is undoubtedly due to soil sample variations.

Strength of frozen saline soils

1995 ◽  
Vol 32 (2) ◽  
pp. 336-354 ◽  
Author(s):  
E.G. Hivon ◽  
D.C. Sego
Keyword(s):  
Water Content ◽  
Fine Particles ◽  
Constant Strain Rate ◽  
Significant Loss ◽  
Time Domain Reflectometry ◽  
Frozen Soil ◽  
Unfrozen Water ◽  
Strain Behavior ◽  
Unfrozen Water Content ◽  
The Time Domain

This paper summarizes an extensive laboratory program undertaken to study the influence of soil type, temperature, and salinity on the strength of three different frozen soils under conditions of unconfined constant strain rate tests. Since the effects of temperature and salinity can be unified by studying the variation of unfrozen water content, measurements of unfrozen water at different temperatures were carried out using the time-domain reflectometry (TDR) method. The stress–strain behavior is influenced by the presence of fine particles in the soil, and an increase in temperature and salinity (unfrozen water content) causes a significant loss of strength. For each soil tested, a predictive model of its strength in terms of salinity and temperature (unfrozen water content) is presented. Key words : frozen soil, saline, unfrozen water, strength.

scholarly journals Frost Heave due to Ice Lens Formation in Freezing Soils

1995 ◽  
Vol 26 (2) ◽  
pp. 125-146 ◽  
Author(s):  
D. Sheng ◽  
K. Axelsson ◽  
S. Knutsson
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Frost Heave ◽  
Darcy Law ◽  
Unfrozen Water ◽  
Clapeyron Equation ◽  
Unfrozen Water Content ◽  
Steady State Heat ◽  
Ice Pressure ◽  
Lens Formation

A frost heave model which simulates formation of ice lenses is developed for saturated salt-free soils. Quasi-steady state heat and mass flow is considered. Special attention is paid to the transmitted zone, i.e. the frozen fringe. The permeability of the frozen fringe is assumed to vary exponentially as a function of temperature. The rates of water flow in the frozen fringe and in the unfrozen soil are assumed to be constant in space but vary with time. The pore water pressure in the frozen fringe is integrated from the Darcy law. The ice pressure in the frozen fringe is determined by the generalized Clapeyron equation. A new ice lens is assumed to form in the frozen fringe when and where the effective stress approaches zero. The neutral stress is determined as a simple function of the unfrozen water content and porosity. The model is implemented on an personal computer. The simulated heave amounts and heaving rates are compared with experimental data, which shows that the model generally gives reasonable estimation.

Unfrozen water content in saline soils: results using time-domain reflectometry

1985 ◽  
Vol 22 (1) ◽  
pp. 95-101 ◽  
Author(s):  
D. E. Patterson ◽  
M. W. Smith
Keyword(s):  
Water Content ◽  
Time Domain ◽  
Time Domain Reflectometry ◽  
Frozen Soil ◽  
Probe Design ◽  
Unfrozen Water ◽  
Use Of Time ◽  
Unfrozen Water Content ◽  
Pore Water Salinity ◽  
Apparent Dielectric Constant

The use of time-domain reflectometry (TDR) for determining the phase composition of saline permafrost from measurement of the apparent dielectric constant, Ka, is examined.Combined TDR–dilatometry experiments were performed to assess whether the TDR method could be used on frozen soil samples with high pore water salinity. In general, unfrozen water content determinations by TDR were within ±0.025 cm3∙cm−3 of those obtained by dilatometry, with no marked influence due to salinity. A novel probe design for use on saline core samples shows promise as a means for determining unfrozen water contents in the field.

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