Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Dynamic Shear Behavior Characteristics of PHC Pile-cohesive Soil Ground Contact Interface Considering Various Environmental Factors

다양한 환경인자를 고려한 PHC 말뚝-사질토 지반 접촉면의 동적 전단거동 특성

  • 김영준 (한서대학교 건설공학과) ;
  • 곽창원 (인하공업전문대학 건설환경공학과) ;
  • 박인준 (한서대학교 인프라시스템학과 )
  • Received : 2023.11.14
  • Accepted : 2024.01.16
  • Published : 2024.02.29
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Abstract

PHC piles demonstrate superior resistance to compression and bending moments, and their factory-based production enhances quality assurance and management processes. Despite these advantages that have resulted in widespread use in civil engineering and construction projects, the design process frequently relies on empirical formulas or N-values to estimate the soil-pile friction, which is crucial for bearing capacity, and this reliance underscores a significant lack of experimental validation. In addition, environmental factors, e.g., the pH levels in groundwater and the effects of seawater, are commonly not considered. Thus, this study investigates the influence of vibrating machine foundations on PHC pile models in consideration of the effects of varying pH conditions. Concrete model piles were subjected to a one-month conditioning period in different pH environments (acidic, neutral, and alkaline) and under the influence of seawater. Subsequent repeated direct shear tests were performed on the pile-soil interface, and the disturbed state concept was employed to derive parameters that effectively quantify the dynamic behavior of this interface. The results revealed a descending order of shear stress in neutral, acidic, and alkaline conditions, with the pH-influenced samples exhibiting a more pronounced reduction in shear stress than those affected by seawater.

PHC 말뚝은 압축력 및 휨 모멘트에 대한 저항력이 우수하며, 공장에서의 생산으로 인해 품질 관리가 효율적으로 이루어진다. 이러한 장점으로 인해 다양한 토목 및 건축 현장에서 널리 활용되고 있지만, PHC 말뚝의 설계 과정에서 중요한 요소인 주면 마찰력은 주로 경험식이나 N 값 등의 추정치를 기반으로 하고 있다. 이에 대한 실험적 연구는 상대적으로 부족하며, 환경적 요소 중 하나인 pH 값과 지하수 또는 해수의 영향 역시 간과되는 경우가 많다. 본 연구에서는 진동기계 기초의 영향을 받는 PHC 말뚝 모델을 중심으로 다양한 pH 환경(산성, 중성, 염기성) 및 해수의 영향하에 한 달 동안 수침 후, 해당 PHC 말뚝-사질토의 접촉면에 대한 반복 단순 전단시험을 수행하였다. 이를 위해 교란 상태 개념(Disturbed State Concept)을 적용하여 접촉면의 동적 거동을 정량적으로 평가하였다. 연구 결과, 화학적 환경에 따른 동적 전단응력은 중성 > 산성 > 염기성 순으로 감소하였다. 또한, pH 영향을 받은 경우와 해수의 영향을 받은 경우를 비교했을 때, pH 영향을 받은 경우에 전단응력의 감소가 더 크게 나타났다.

Keywords

Acknowledgement

본 연구는 한국연구재단 중견연구지원사업(2021R1A2C10955891331682007070103)지원으로 수행되었으며, 이에 깊은 감사를 드립니다.

References

  1. Alanazy, A.S. (1996), "Testing and Modeling of Sans-Steel Interfaces Under Static and Cyclic Loading", Ph.D Dissertation, Dept. of Civil Engrg and Engrg. Mech. Univ of Arizona, Tucson, Arizona. 
  2. Armaleh, S.H. and Desai, C.S. (1990), "Modeling Include Testing of Cohesingless Soils under Disturbed State Concopt", Report to the NSF, Dept of Civil Engrg and Engrg Mech Univ of Arizona, Tuscon, Arizona. 
  3. Choi, Y.K., Lee, W.J., Lee, C.U., and Kwon, O.K. (2019), "Study(I) on Develoment of Charts and Formulae Prediction Allowable Axial Bearing Capacity for Prebored PHC Pile Socketed into Weathered Rock through Sandy Soil Layer - An Analysis of Sharing Ratio of Skin Friction to Total Bearing Capacity (SRF) by Analyzing Pile Load Test Data-", Journal of the Korean Geotechnical Society, Vol.35, No.8, pp.17-30.  https://doi.org/10.7843/KGS.2019.35.8.17
  4. Huang, F.Y., Wu, S.W., Luo, X.Y., Chen, B.C., and Lin, Y. (2018), "Pseudo-static Low Cycle Test on the Mechanical behavior of PHC Pipe Piles with Consideration of Soil-pile Interaction", Engineering Structures, Vol.171, No.15, pp.992-1006. 
  5. Jang, D.I., Kim, Y.J., Kwak, C.W., and Park, I.J. (2015), "Dynamic Shear Behavior of the Ground-geosynthetics Interface in the Waste Landfill", Journal of the Korean Geotechnical Society, Vol.31, No.4, pp.5-12.  https://doi.org/10.7843/KGS.2015.31.4.5
  6. Kim, B.I., Lee, S.H., Kim, Y.U ., Jo, S.M., Yoon, C.Y., and Jo, Y.J. (2013), "Foundation Engineering", MoonUnDang, ISBN 978-89-7393-985-5, pp.167. 
  7. Kwak, C.W. (2022), "Characteristics of Dynamic Shear Bbehavior of Pile-Soil Interface Considering pH Conditions of Groundwater", Journal of the Korean Geotechnical Society, Vol.38, No.5, pp. 55-17.
  8. Kwak, C.W., Park, I.J., and Park, J.B. (2013), "Evaluation of Disturbance Function for Geosynthetic-soil Interface Considering Chemical Reactions based on Cyclic Direct Shear Tests", Soils and Foundations, Vol.53, No.5, pp.720-734. 
  9. Kwak, C.W. (2014), "Cyclic Shear Behaviors of Geosynthetic-Soil Interface Considering Chemical Effeccts", Ph.D. Dissertation, Department of Civil and Environmental Engineering Seoul National Unversity, Seoul, Korea. 
  10. Kwak, C.W., Park, J.B., Jang, D.I., and Park, I.J. (2017), "Dynamic Shear Degradation of Geosynthetic-Soil Interface in Waste Landfill Sites", Applied Science, Vol.7, No.1225, doi:10.3390/app7121225 
  11. Luo, X., Huang, F., Zhuang, Y., Wu, S., and Qian, H. (2019), "Modified Calculations of Lateral Displacement and Soil Pressure of Pile Considering Pile-Soil Interaction under Cyclic Loads", Journal of Testing and Evaluation, Vol.49, No.4, 10.1520/JTE20190267. 
  12. Park, I.J. and Desai, C.S. (2000), "Cylic Behavior and Liquefaction of Sand Using Disturbed State Concept", Journal of Geotechnical and Geoenvironmental Engineering", ASCE, Vol.1236, No.9, pp. 834-846. 
  13. Park, T.K., Lee, J.C., and Lee, C.S. (2008), "Problems and Improvement Measure of PHC Pile Construciton", Proceedings of Korea Institute of Construction Engineering and Mangment, Nov., No.07, pp.344-348. 
  14. Shin, B.S., Choi, Y.S., and Bong, S.K., (2012), "Vibration Reduction of a LP Steam Turbine having Support Subsidence", Korean Society of Noise and Vibration Engineering Paper Collection, Vol.22, No.1, pp.74-80. 
  15. Shin, K.S. and Lim, B.H. (2018), "Engineering Properties of PHC Pile Considering Replacement Ratio of Ground Granulated BlastFurnace Slag and Curing Conditions", Journal of Korea Institute of Buliding Construction, Vol.18, No.5, pp.439-446. 
  16. Tomlinson, M.J. (1994), "Pile Design and Construction Practice 4th Edition", E & FN Spon., pp.133-134. 
  17. Tran, N.X., Bong, T., Yoo, B.S., and Kim, S.R. (2021), "Evaluation of the Soil-pile Interface Properties in the Lateral Direction for Seismic Analysis in Sand", Soil Dynamics and Earthquake Engineering, Vol.140, 106473. 
  18. Yoo, J.W., Kim, T.H., Kim, S.K., and Han, C.H. (2002), "A Study on the Improvement Method of Construction Management for PHC Pile in an Apartment house", Proceedings of Korea Institute of Construction Engineering and Management, pp.244-247. 
  19. Yoo, M.T., Back, M.C., Lee, I.H., and Lee, J.S. (2017), "Evaluation of Dynamic Behavior for Pile-Supported Slab Track System by 3D Numerical Analysis", Jorunal of the Earthquake Engineering Society of Korea, Vol.21 No.5, pp.255-264.