DOI QR코드

DOI QR Code

A laboratory pressurized vane test for evaluating rheological properties of excavated soil for EPB shield TBM: test apparatus and applicability

EPB 쉴드 TBM 굴착토의 유동학적 특성 평가를 위한 실내 가압 베인시험: 장비 개발과 적용성 평가

  • Kwak, Junho (School of Civil, Environmental and Architectural Engineering, Korea University) ;
  • Lee, Hyobum (Advanced Railroad Civil Engineering Division, Korea Railroad Research Institute) ;
  • Hwang, Byeonghyun (School of Civil, Environmental and Architectural Engineering, Korea University) ;
  • Choi, Junhyuk (School of Civil, Environmental and Architectural Engineering, Korea University) ;
  • Choi, Hangseok (School of Civil, Environmental and Architectural Engineering, Korea University)
  • 곽준호 (고려대학교 건축사회환경공학과) ;
  • 이효범 (한국철도기술연구원 첨단궤도토목본부) ;
  • 황병현 (고려대학교 건축사회환경공학과) ;
  • 최준혁 (고려대학교 건축사회환경공학과) ;
  • 최항석 (고려대학교 건축사회환경공학부)
  • Received : 2022.03.08
  • Accepted : 2022.08.10
  • Published : 2022.09.30

Abstract

Soil conditioning improves the performance of EPB (earth pressure balance) shield TBMs (tunnel boring machines) by reducing shear strength, enhancing workability of the excavated soil, and supporting the tunnel face during EPB tunnelling. The mechanical and rheological behavior of the excavated muck mixed with additives should be properly evaluated to determine the optimal additive injection condition corresponding to each ground type. In this study, the laboratory pressurized vane test apparatus equipped with a vane-shaped rheometer was developed to reproduce the pressurized condition in the TBM chamber and quantitively evaluate rheological properties of the soil specimens. A series of the pressurized vane tests were performed for an artificial sand soil by changing foam injection ratio (FIR) and polymer injection ratio (PIR), which are the injection parameters of the foam and the polymer, respectively. In addition, the workability of the conditioned soil was evaluated through the slump test. The peak and yield stresses of the conditioned soil with respect to the injection parameters were evaluated through the rheogram, which was derived from the measured torque data in the pressurized vane test. As FIR increased or PIR decreased, the workability of the conditioned soil increased, and the maximum torque, peak stress, and yield stress decreased. The peak stress and yield stress of the specimen from the laboratory pressurized vane test correspond to the workability evaluated by the slump tests, which implies the applicability of the proposed test for evaluating the rheological properties of excavated soil.

쏘일 컨디셔닝(soil conditioning)은 굴착토의 전단강도를 감소시키고 작업성(workability)을 확보하여, EPB 쉴드 TBM의 굴진면 전방을 지지하며 TBM의 굴진 성능을 향상시키는 기술이다. 다양한 지반 조건에 대한 최적의 첨가제 주입 조건을 결정하기 위해서는 첨가제를 혼합한 굴착토의 역학적 유동학적 거동을 평가해야 한다. 따라서, 본 연구에서는 TBM 챔버 내 압력 상태를 모사하고 시료의 유동학적 특성을 평가할 수 있는 실내 가압 베인시험 장비를 개발하였다. 인공 사질토 시료에 대하여 폼(foam)과 폴리머(polymer)의 주입변수인 FIR (foam injection ratio)과 PIR (polymer injection ratio)을 변화시켜가며 일련의 실내 가압 베인시험을 수행하였다. 또한, 슬럼프 시험을 통해 컨디셔닝된 흙의 작업성을 평가하였다. 실내 가압 베인시험 장비를 통해 베인 전단시험을 수행함으로써 측정된 토크 데이터로부터 컨디셔닝된 흙의 유동곡선(rheogram)을 도출하여 주입변수에 따른 첨두응력과 항복응력의 경향을 분석하였다. 시험 결과, FIR이 커지거나 PIR이 작아질수록 작업성이 증가하는 경향을 나타냈으며, 최대 토크, 첨두응력과 항복응력은 모두 감소하였다. 실내 가압 베인시험으로 측정된 시료의 첨두응력과 항복응력이 슬럼프 시험을 통해 측정된 작업성과 상응하는 결과는 제안된 시험이 굴착토 물성 평가에 활용될 수 있음을 보여준다.

Keywords

Acknowledgement

이 연구는 국토교통부/국토교통과학기술진흥원이 시행하고 한국도로공사가 총괄하는 "스마트건설기술개발국가R&D사업(과제번호 22SMIP-A158708-03)"의 지원으로 수행하였습니다.

References

  1. ASTM C143 (2017), Standard test method for slump of hydraulic-cement concrete, ASTM International, Vol. 04.02, pp. 1-4.
  2. ASTM D4648 (2016), Standard test method for laboratory miniature vane shear test for saturated finegrained clayey soil, ASTM International, Vol. 04.08, pp. 1-7.
  3. Avunduk, E., Copur, H., Tolouei, S., Tumac, D., Balci, C., Bilgin, N., Shaterpour-Mamaghani, A. (2021), "Possibility of using torvane shear testing device for soil conditioning optimization", Tunnelling and Underground Space Technology, Vol. 107, 103665. https://doi.org/10.1016/j.tust.2020.103665
  4. Bavasso, I., Vilardi, G., Sebastiani, D., Di Giulio, A., Di Felice, M., Di Biase, A., Miliziano, S., Di Palma, L. (2020), "A rapid experimental procedure to assess environmental compatibility of conditioning mixtures used in TBM-EPB technology", Applied Sciences, Vol. 10, No. 12, pp. 4138-4150. https://doi.org/10.3390/app10124138
  5. EFNARC (2005), Specification and guidelines for the use of specialist products for mechanised tunnelling (TBM) in soft ground and hard rock. European Federation of National Associations Representing for Concrete, pp. 1-45.
  6. Galli, M., Thewes, M. (2019), "Rheological characterisation of foam-conditioned sands in EPB tunneling", International Journal of Civil Engineering, Vol. 17, pp. 145-160. https://doi.org/10.1007/s40999-018-0316-x
  7. Ghica, M.V., Hirjau, M., Lupuleasa, D., Dinu-Pirvu, C.E. (2016), "Flow and thixotropic parameters for rheological characterization of hydrogels", Molecules, Vol. 21, No. 6, pp. 786-802. https://doi.org/10.3390/molecules21060786
  8. Hu, W., Rostami, J. (2021), "Evaluating rheology of conditioned soil using commercially available surfactants (foam) for simulation of material flow through EPB machine", Tunnelling and Underground Space Technology, Vol. 112, 103881. https://doi.org/10.1016/j.tust.2021.103881
  9. Jancsecz, S., Krause, R., Langmaack, L. (1999), "Advantages of soil conditioning in shield tunneling: experiences of LRTS Izmir", Challenges for the 21st Century: Proceedings of the World Tunnel Congress '99, Vol. 2, Oslo, pp. 865-875.
  10. Karmakar, S., Kushwaha, R.L. (2007), "Development and laboratory evaluation of a rheometer for soil visco-plastic parameters", Journal of Terramechanics, Vol. 44, No. 2, pp. 197-204. https://doi.org/10.1016/j.jterra.2006.10.002
  11. Kim, T.H., Kim, B.K., Lee, K.H., Lee, I.M. (2019), "Soil conditioning of weathered granite soil used for EPB shield TBM: a laboratory scale study", KSCE Journal of Civil Engineering, Vol. 23, No. 4, pp. 1829- 1838. https://doi.org/10.1007/s12205-019-1484-1
  12. Kim, T.H., Kwon, Y.S., Chung, H., Lee, I.M. (2018), "A simple test method to evaluate workability of conditioned soil used for EPB shield TBM", Journal of Korean Tunnelling and Underground Space Association, Vol. 20, No. 6, pp. 1049-1060. https://doi.org/10.9711/KTAJ.2018.20.6.1049
  13. Kim, T.H., Lee, I.M., Chung, H.Y., Park, J.J., Ryu, Y.M. (2021), "Application ranges of EPB shield TBM in weathered granite soil: a laboratory scale study", Applied Sciences, Vol. 11, No. 7, pp. 2995-3009. https://doi.org/10.3390/app11072995
  14. Langmaack, L. (2000), "Advanced technology of soil conditioning in EPB shield tunneling", Proceedings of the North American Tunneling, Vol. 2000, Boston, pp. 525-542.
  15. Lee, H. (2021), Evaluation on performance of EPB shield tunnelling with foam conditioning, Ph.D. Thesis, Korea University, pp. 1-272.
  16. Lee, H., Kim, D.Y., Shin, D., Oh, J., Choi, H. (2022), "Effect of foam conditioning on performance of EPB shield tunnelling through laboratory excavation test", Transportation Geotechnics, Vol. 32, 100692. https://doi.org/10.1016/j.trgeo.2021.100692
  17. Lee, H., Shin, D., Kim, D.Y., Shin, Y.J., Choi, H. (2019), "Study on EPB TBM performance by conducting lab-scaled excavation tests with different foam injection for artificial sand", Journal of Korean Tunnelling and Underground Space Association, Vol. 21, No. 4, pp. 545-560. https://doi.org/10.9711/KTAJ.2019.21.4.545
  18. Maidl, U. (1995), Erweiterung der Einsatzbereiche der Erddruckschilde durch bodenkonditionierung mit Schaum, Ph.D. Thesis, Institut fur Konstruktiven Ingenieurbau, Ruhr-Universitat Bochum, pp. 1-184.
  19. Meng, Q., Qu, F., Li, S. (2011), "Experimental investigation on viscoplastic parameters of conditioned sands in earth pressure balance shield tunneling", Journal of Mechanical Science and Technology, Vol. 25, No. 9, pp. 2259-2266. https://doi.org/10.1007/s12206-011-0611-9
  20. Merritt, A.S., Borghi, F.X., Mair, R.J. (2003), "Conditioning of clay soils for earth pressure balance tunnelling machines", Proceedings of the Underground Construction 2003, London, pp. 455-466.
  21. Messerklinger, S., Zumsteg, R., Puzrin, A.M. (2011), "A new pressurized vane shear apparatus", Geo-technical Testing Journal, Vol. 34, No. 2, pp. 112-121.
  22. Mori, L. (2016), Advancing understanding of the relationship between soil conditioning and earth pressure balance tunnel boring machine chamber and shield annulus behavior, Ph.D. Thesis, Colorado School of Mines, pp. 1-191.
  23. Peila, D. (2014), "Soil conditioning for EPB shield tunnelling", KSCE Journal of Civil Engineering, Vol. 18, No. 3, pp. 831-836. https://doi.org/10.1007/s12205-014-0023-3
  24. Peila, D., Oggeri, C., Borio, L. (2009), "Using the slump test to assess the behavior of conditioned soil for EPB tunneling", Environmental & Engineering Geoscience, Vol. 15, No. 3, pp. 167-174. https://doi.org/10.2113/gseegeosci.15.3.167
  25. Peila, D., Oggeri, C., Vinai, R. (2007), "Screw conveyor device for laboratory tests on conditioned soil for EPB tunneling operations", Journal of Geotechnical and Geoenvironmental Engineering, Vol. 133, No. 12, pp. 1622-1625. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:12(1622)
  26. Quebaud, S., Sibai, M., Henry, J.P. (1998), "Use of chemical foam for improvements in drilling by earth-pressure balanced shields in granular soils", Tunnelling and Underground Space Technology, Vol. 13, No. 2, pp. 173-180. https://doi.org/10.1016/S0886-7798(98)00045-5
  27. Shin, D. (2020), Evaluation of EPB TBM excavation performance on artificial sandy soils with foam injection conditions, Master Thesis, Korea University, pp. 1-272.
  28. Thewes, M., Budach, C., Bezuijen, A. (2012), "Foam conditioning in EPB tunnelling", In Geotechnical Aspects of Underground Construction in Soft Ground, Taylor & Francis, London, Vol. 36, pp. 127-135.
  29. Vinai, R., Oggeri, C., Peila, D. (2008), "Soil conditioning of sand for EPB applications: a laboratory research", Tunnelling and Underground Space Technology, Vol. 23, No. 3, pp. 308-317. https://doi.org/10.1016/j.tust.2007.04.010
  30. Zhou, X., Yang, Y. (2020), "Effect of foam parameters on cohesionless soil permeability and its application to prevent the water spewing", Applied Sciences, Vol. 10, No. 5, pp. 1787-1797. https://doi.org/10.3390/app10051787
  31. Zumsteg, R., Messerklinger, S., Puzrin, A.M., Egli, H., Walliser, A. (2009), "Pressurized vane shear test for soil conditioning", Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering, Alexandria, pp. 275-278.