Long-term measurement of matric suction using thermal conductivity sensors

Thermal conductivity (TC) sensors, which provide estimates of matric suction, were used in a field experiment designed to characterize unsaturated water movement through coarse mine waste rock at a mine site in northern Saskatchewan. Two years of monitoring data were used to evaluate long-term TC sensor performance and accuracy. Thermal conductivity sensor output requires corrections of sensor hysteresis and changes in ambient temperature. A correction method for ambient temperature is derived. A comparison of the uncorrected field measurements with the values corrected for both hysteresis and ambient temperature indicates that the magnitude of these corrections can be similar. Corrected TC sensor measurements are compared to measurements of matric suction made using tensiometers. Thermal conductivity sensor response to the initial arrival of a wetting front lagged 1–3 days behind the tensiometer measurements. The TC sensor data tended to overestimate matric suction in the waste rock, when compared to the...

[1]  A. Klute,et al.  Water Potential: Tensiometry , 2018, SSSA Book Series.

[2]  Time domain reflectrometry measurements of water content in coarse waste rock , 2003 .

[3]  Delwyn G. Fredlund,et al.  A LABORATORY STUDY OF THE HYSTERESIS OF A THERMAL CONDUCTIVITY SOIL SUCTION SENSOR , 2002 .

[4]  D. Fredlund,et al.  Some Factors that Influence Soil Suction Measurements Using a Thermal Conductivity Sensor , 2002 .

[5]  D. G. Fredlund,et al.  Use of a New Thermal Conductivity Sensor to Measure Soil Suction , 2000 .

[6]  P. Starks.  A general heat dissipation sensor calibration equation and estimation of soil water content , 1999 .

[7]  G. Wilson,et al.  Instrumentation and monitoring of an engineered soil cover system for mine waste rock , 1998 .

[8]  G. Wilson,et al.  Heat and mass transfer in unsaturated soils during freezing , 1997 .

[9]  C. Reece.  Evaluation of a Line Heat Dissipation Sensor for Measuring Soil Matric Potential , 1996 .

[10]  Kl Greenwood,et al.  A double-puncture technique for improving the accuracy of puncture tensiometer measurements , 1996 .

[11]  A. Xing,et al.  Numerical Modeling of a Thermal Conductivity Matric Suction Sensor , 1994 .

[12]  D. Fredlund,et al.  Soil Mechanics for Unsaturated Soils , 1993 .

[13]  Delwyn G. Fredlund,et al.  Use of thermal conductivity sensors to measure matric suction in the laboratory , 1989 .

[14]  Dkh Wong,et al.  EVALUATION OF AGWA-II THERMAL CONDUCTIVITY SENSORS FOR SOIL SUCTION MEASUREMENT , 1989 .

[15]  A W Clifton,et al.  SOIL SUCTION MEASUREMENTS AT SEVERAL SITES IN WESTERN CANADA , 1987 .

[16]  David I. Stannard.  Theory, Construction and Operation of Simple Tensiometers , 1986 .

[17]  R. C. Weast.  Handbook of chemistry and physics , 1973 .

[18]  Glenn J. Hoffman,et al.  Measuring Soil Matric Potential in situ by Sensing Heat Dissipation within a Porous Body: I. Theory and Sensor Construction 1 , 1971 .

[19]  S. L. Rawlins,et al.  Measuring Soil Matric Potential in situ by Sensing Heat Dissipation within a Porous Body: II. Experimental Results1 , 1971 .