Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
권호 표지
DOI QR코드

DOI QR Code

Temperature Transition Characteristics of Penetration Type Probes

관입형 프로브의 온도전이 특성

  • 정순혁 (대림산업(주) 기술개발원) ;
  • 윤형구 (고려대학교 건축사회환경공학부) ;
  • 이종섭 (고려대학교 건축사회환경공학부)
  • Published : 2011.03.01
⟨ Previous Next ⟩

Abstract

Various penetration type penetrometers such as CPT and DMT have been used for obtaining high resolution soil properties under the minimized disturbance effects. The cone type penetrometer, which can measure cone tip resistance, sleeve friction, and pore-water pressure using strain gauge type sensor and electrical resistivity probe, is affected by temperature changes during penetration into soils. In this study, temperature transition probe(TTP) whose diameters are 5mm and 10mm are manufactured using thermometer and temperature sensor. The internal temperature transient process of cone penetrometer is analyzed in various soil conditions. The temperature sensor is attached on 4 points of cone inside in consideration with electrical disturbance between electrical resistivity module and temperature sensor itself and the adhesion points of strain gauges. The test was performed in large-scale acrylic cell with 30-cm diameter and 60-cm height and small-scale cell with 20-cm diameter and 40-cm height using Jumunjin sand and glass beads, respectively, as controlling densities and temperatures of specimens under saturated conditions. The test results indicate that the larger temperature changes generate in the denser soils and the temperature of soil samples around the probe affects the temperature changes inside of the probes. Thus, the objective of this study was to develop the temperature transient probe and to propose that temperature compensation should be considered in order to obtain more accurate in-situ results.

지반조사 및 시료의 물성치 획득 시 교란의 영향을 최소화하고 해상도 높은 데이터를 연속적으로 획득하기 위해서 CPT, DMT 등을 비롯한 다양한 종류의 현장 관입시험기가 이용되고 있다. 이때 선단저항력과 주면마찰력 및 간극수압의 측정을 위해서 전기저항식 변형률계나 전기비저항 프로브를 이용하는 관입시험기의 경우 온도 변화에 의해 측정값이 영향을 받게 된다. 본 논문에서는 전기저항식 온도측정장치 및 온도센서를 이용하여 직경 5mm와 직경 10mm의 온도 전이 측정분석용 프로브를 제작하고 관입실험을 실시하여 다양한 조건에서의 콘 내부 온도 전이 과정을 분석하였다. 온도센서는 전기비저항 프로브와의 전기적 간섭현상과 프로브 내부의 전기저항식 변형률계 부착 위치를 고려하여 선단부를 포함하여 콘 내부의 4곳에 부착하였다. 실험은 직경 30cm 높이 60cm의 대형 아크릴 셀과 직경 20cm, 높이 40cm의 소형 아크릴 셀에서 각각 주문진사와 글라스비즈를 이용하여 시료를 조성하고, 포화 상태에서 시료의 밀도와 시료 표면의 온도를 조절하면서 실험을 진행하였다. 실험 결과, 시료의 밀도가 큰 시료에서 더 큰 온도 변화가 일어났다. 또한, 관입되는 프로브 주변의 온도가 프로브 내부 온도 변화에 큰 영향을 미치는 것으로 나타났다. 본 연구는 온도 전이 측정용 콘을 개발하고 다양한 조건에서의 실내 관입 실험을 통해 정확한 지반조사를 위해서는 온도에 대한 보정이 필요함을 보여준다.

Keywords

References

  1. 김래현, 이종섭, 안신환, 이우진(2010), FBG센서를 이용한 콘선단저항력의 온도영향 보상, 한국지반공학회 논문집, Vol. 25, No. 10, pp. 31-40.
  2. 김준한, 윤형구, 정순혁, 이종섭(2009a), 4전극 전기비저항 탐사장비의 개발 및 검증, 대한토목학회 논문집, Vol. 29, No. 3c, pp. 127-136.
  3. 김준한, 윤형구, 최용규, 이종섭(2009b), 전기비저항 콘 프로브를 이용한 해안 연약지반의 간극률 평가, 한국지반공학회논문집, Vol. 25, No. 2, pp. 45-54.
  4. 윤형구, 이창호, 김준한, 이종섭(2009), 미소변형 전단파 속도를 고려한 선행압밀하중 산정, 한국지반공학회 논문집, Vol. 26, No. 5, pp. 5-16.
  5. ASTM Standard D5778-95.(2000), Standard Test Method for Performing Electrocnic Friction Cone and Piezo Penetration Testing of soils, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA.
  6. Bemben, S. M. and Myers, H. J.(1974), The Influence of Rate of Penetration on Static Cone Resistance in Connecticut River Valley Varved Clay, Proceedings of the European Symposium on Penetration Testing, Stockholm, Vol. 2, No. 2, pp. 33-34.
  7. Buteau, S., Fortier, R., and Allard, M.(2005), Rate-controlled Cone Penetration Tests in Permafrost, Canadian Geotechnical Journal, Vol. 42, pp. 184-197. https://doi.org/10.1139/t04-093
  8. Campanella, R. G. and Weemees, I.(1990), Development and Use of an Electrical Resistivity Cone for Groundwater Contamination Studies, Candian Geotehnical Journal, Vol. 27, pp. 557-567. https://doi.org/10.1139/t90-071
  9. Cho, G. C., Lee, J. S., and Santamarina, J. C.(2004), Spatial Variability in Soils: High Resolution Assessment with Electrical Needle Probe, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 130, No.8, pp. 843-850. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:8(843)
  10. De Lima, D. C. and Tumay, M. T.(1991), Scale Effects in Cone Penetration Tests, Proceedings of the Geotechnical Engineering Congress 1991, ASCE, Boulder, Colorado, 1, pp. 38-51.
  11. Ferreira, M. P. and Negrao, J. H.(2006), Effects of Spatial Variability of Earthquake Ground Motion in Cable-stayed Bridges, Structural Engineering and Mechanics, Vol. 23, No. 3, pp. 233-247. https://doi.org/10.12989/sem.2006.23.3.233
  12. Griffiths, D. V. and Fenton, G. A.(2001), Bearing Capacity of Spatially Random Soil: the Undrained Clay Prandtl Problem Revisited, Geotechnique, Vol. 51, No. 4, pp. 351-359. https://doi.org/10.1680/geot.2001.51.4.351
  13. ISSMFE.(1989), International Reference Test Procedure for Cone Penetration Test(CPT), Report of the ISSMFE Technical Committee on Penetration Testing of Soils-TC16, with Reference to Test Procedures, Swedishi Geotechnical Institute, Linkoping Information, pp. 6-16.
  14. Kim, H. K. and Santamarina, J. C.(2008), Spatial Variability: Drained and Undrained Deviatoric Load Response, Geotechnique, Vol. 58, No. 8, pp. 805-814. https://doi.org/10.1680/geot.2008.3724
  15. Kim, J. H., Yoon, H. K., and Lee, J. S.(2010a), Void Ratio Estimation of Seashore Soft Soils by Electrical Resistivity Cone Probe, Journal of Geotechnical and Geoenvironmental Engineering, ASCE (Accepted).
  16. Kim, R., Lee, W., Yoon, H. K., and Lee, J. S.(2010b), Temperature Compensated Cone Penetrometers by Using Fiber Optical Sensors, Geotechnical Testing Journal, ASTM, Vol. 33, No. 3, pp. 1-10.
  17. Kwon, T. H. and Cho, G. C.(2005), Smart Geophysical Characterization of Particulate Materials in a Laboratory, Smart Structures and Systems, Vol. 1, No. 2, pp. 217-233. https://doi.org/10.12989/sss.2005.1.2.217
  18. Lee, J. S. and Santamarina, J. C.(2007), Seismic Monitoring Short-duration Events - liquefaction in 1g Models, Canadian Geotechnical Journal, Vol. 44, No. 6, pp. 659-672. https://doi.org/10.1139/t07-020
  19. Lee, W., Shin, D. S., Yoon, H. K., and Lee, J. S.(2009), Microcone Penetrometer for Tip Resistance and Layer Detection, Geotechnical Testing Journal, ASTM, Vol. 32, No. 4, PP. 358-364.
  20. Lunne, T., Eidsmoen, T., Gillespie, D., and Howland, J. D. (1986), Laboratory and Field Evaluation of Cone Penetrometers, Proceedings of the ASCE Specialty Conference In Situ '86: Use of In Situ Testes in Geotechnical Engineering, Blacksburg, pp. 714-729.
  21. Lunne, T., Robertson, P. K., and Powell, J. J. M.(1997), Cone Penetration Testing in Geotechnical Practice, Blakie Academic, Great Britain, London, pp. 1-7.
  22. Nishimura, S. I., Shimada, K., and Fujii, H.(2002), Consolidation Inverse Analysis Considering Spatial Variability and Non-linearity of Soil Parameters, Soils and Foundation, Vol. 42, No. 3, pp. 45-61. https://doi.org/10.3208/sandf.42.3_45
  23. Paice, G. M., Griffiths, D. V., and Fenton G. A.(1996), Finite Element Modeling of Settlements on Spatially Random soil, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 122, No. 9, pp. 777-779. https://doi.org/10.1061/(ASCE)0733-9410(1996)122:9(777)
  24. Post, M. L. and Nebbeling, H.(1995), Uncertainties in Cone Penetration Testing, Proceedings of the International Symposium on Cone Penetration Testing, CPT '95, Linkoping, Sweden, Vol. 2, pp. 73-78.
  25. Swedish Geotechnical Society(1992), Recommended Standard for Cone Penetration Tests, Report 1:93 E.
  26. Zeitoun, D. G. and Baker, R.(1992), A Stochastic Approach for Settlement Predictions of Shallow Foundations, Geotechnique, Vol. 42, No. 4, pp. 617-618. https://doi.org/10.1680/geot.1992.42.4.617
  27. Zuidberg, H. M., Hoope, J. ten, and Geise, J. M.(1988), Advances in In-situ Measurements, Proceedings of the 2nd International Symposium on Field Measurements in Geomechnics, Kobe, pp. 279-291.