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Development of a Flat-type TDR System for Compaction Control

다짐관리를 위한 판형 TDR 시스템 개발

Song, Minwoo;Choi, Chanyong;Kim, Daehyeon
송민우;최찬용;김대현

  • Received : 2016.03.14
  • Accepted : 2016.03.28
  • Published : 2016.04.29

Abstract

In this study, a new TDR system equipped with a flat type probe has been developed to improve the currently used TDR system that measures dry density and water content. To verify the developed TDR system, TDR tests were conducted on Jumunjin sand and three typical soils. Also, additional tests were performed to measure the correction value of the developed probe. Using the TDR signals, dielectric constant, electrical conductivity and soil constants were derived. The water content and dry density of the soils were determined through the TDR tests. The applicability of the TDR system was examined by comparison of the measured values by TDR and the real values. The values of dry density and water content were found to have about 2% and 0.5% error, respectively. Based on the test results, it has been confirmed that the new TDR system can be used as an alternative to the previous TDR system as it can measure the dry density and the water content with reasonable accuracy, leading to significant time and cost savings.

Keywords

TDR;Nondestructive system;water content;dry density

References

  1. ASTM D 6780-05. (2005), "Standard Test Method for Water Content and Density of Soil in Place by Time Domain Reflectometry(TDR)", Annual Book of ASTM Standards.
  2. Baker, J.M. and Allmaras, R.R. (1990), "System for Automating and Multiplexing Soil Moisture Measurement by Time-domain Reflectometry", Soil Science Society of America Journal, Vol.54, No.1, pp.1-6. https://doi.org/10.2136/sssaj1990.03615995005400010001x
  3. Cho, M.H. Lee, Y.H. Kim, N.S., and Park, J.Y. (2010), "A Study on Measuring and Calibration Method using Time Domain Reflectometry Sensor under Road Pavement", Journal of Korean Society of Hazard Mitigation, Vol.10, No.2, pp.23-30.
  4. Ferre, P.A., Knight, J.H., Rudolph, D.L., and Kachanoski, R.G. (1998), "The Sample Areas of Conventional and Alternative Time Domain Reflectometry Probes", Water Resources Research, Vol.34, No.11, pp.2971-2979. https://doi.org/10.1029/98WR02093
  5. Giese, K. and Tiemann, R. (1975), "Determination of the Complex Permittivity from Thin-sample Time Domain Reflectometry Improved Analysis of the Step Response Waveform", Advances in Molecular Relaxation Processes, Vol.7, No.1, pp.45-59. https://doi.org/10.1016/0001-8716(75)80013-7
  6. Jung, S., Drnevich, V., and Abou Najm, M. (2013), "New Methodology for Density and Water Content by Time Domain Reflectometry", Journal of Geotechnical and Geoenvironmental Engineering, Vol.139, No.5, pp.659-670. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000783
  7. Kim, K.Y. Han, H.S. Lee, J.H., and Park, M.C. (2011), "Analysis of Saturation and Ground Water Level at Embankment by TDR Sensor", Journal of the Korean Geotechnical Society, Vol.27, No.2, pp.63-72.
  8. Knight, J.H., Ferre, P.A., Rudolph, D.L., and Kachanoski, R. G. (1997), "A numerical analysis of the effects of coatings and gaps upon relative dielectric permittivity measurement with time domain reflectometry", Water resources research, Vol.33, No.6, pp.1455-1460. https://doi.org/10.1029/97WR00435
  9. Sallam, A.M., White, N.K., and Ashmawy, A.K. (2004), "Evaluation of the Purdue TDR Method for Soil Water Content and Density Measurement", Final Report the Florida Department of Transportation, No.BC-353-30.
  10. Siddiqui, S.I. and Drnevich, V.P. (1995), "A New Method of Measuring Density and Moisture Content of Soil Using the Technique of Time Domain Reflectometry", Joint Highway Research Project, Purdue University.
  11. Shin, E.C. Ryu, B.H., and Park, J.J. (2013), "Water Content Calibration of Time-Domain Reflectometry Probe Using Laboratory Model Test", Journal of the Korean Geosynthetic Society, Vol.12, No.2, pp.1-11.
  12. Topp, G.C., Davis, J.L., and Annan, A.P. (1980), "Electromagnetic Determination of Soil Water Content: Measurements in Coaxial Transmission Lines", Water resources research, Vol.16, No.3, pp.574-582. https://doi.org/10.1029/WR016i003p00574
  13. Yu, X. and Drnevich, V.P. (2004), "Soil Water Content and Dry Density by Time Domain Reflectometry", Journal of Geotechnical and Geoenvironmental Engineering, Vol.130, No.9, pp.922-934. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:9(922)

Acknowledgement

Supported by : 국토교통부