한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

  • 제36권11호
  • /
  • Pages.157-165
  • /
  • 2020
  • /
  • 1229-2427(pISSN)
  • /
  • 2288-646X(eISSN)
한국지반공학회 (Korean Geotechnical Society)
권호 표지
DOI QR코드

DOI QR Code

진동기 얕은기초에 추가되는 동적 연직하중 산정을 위한 모형실험 방안 연구

A Study on the Model Test for Estimating Dynamic Vertical Load Added to Shallow Foundation for Machine

  • 하익수 (경남대학교 토목공학과) ;
  • 유민택 (철도기술연구원 철도구조연구팀)
  • Ha, Ik-Soo (Dept. of Civil Engrg., Kyungnam Univ.) ;
  • Yoo, Mintaek (Railroad Structure Research Team, Korea Railroad Research Institute)
  • 투고 : 2020.11.02
  • 심사 : 2020.11.05
  • 발행 : 2020.11.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

현재 국내외에서는 진동기계기초에 진동으로 발생하는 추가 연직 동하중을 산정하고 설계함에 있어서 명확하게 제시된 기준이나 이론이 정립되어 있지 않아 국내의 경우, 심각한 진동조건이 아님에도 불구하고 진동에 의한 추가 동하중을 정적하중의 최대 100%로 간주하는 극히 보수적인 설계가 이루어지고 있다. 본 연구의 목적은 연직 기계진동으로 인하여 정하중외에 추가적으로 발생하는 동적하중의 정량적 크기를 평가하기 위한 모형실험 방안을 제시하는 것이다. 실내 모형실험의 기초실험으로, 제한된 크기의 모형 토조 내에서 발생할 수 있는 진동 반사파의 영향을 분석 및 보완하였고, 제작한 모형 진동기계기초의 고유진동수를 산정하여 실험 시 공진영향을 최소화하였다. 제안된 기법을 적용한 본 모형실험을 수행하여, 중간 조밀도의 모래 기초지반에 놓인 기계진동 얕은 기초에 기계진동에 의해 발생하는 추가적인 동하중의 정량적 크기를 평가해 보았다. 모형실험결과로부터, 현재 국내외에서 제시하고 있는 설계기법의 적합성을 논의해 보았다.

At present, there are no clearly stated criteria or theories in calculating additional vertical dynamic loads that occur at the machine foundation due to vibration and reflecting them in the design at home and abroad. According to the domestic standard, although it is not a serious vibration condition, the additional dynamic load due to vibration is considered up to 100% of the static load. This is an extremely conservative design. The purpose of this study is to propose a model test method for evaluating the quantitative magnitude of additional dynamic loads that are generated at certain static loads due to vertical mechanical vibrations. As preliminary basic tests for the model tests, the test for evaluating the effects of reflective wave that may occur within a limited size soil box and the test for estimating the natural frequency of the devised model soil-foundation system were carried out. From the analysis of results for basic tests, a method to minimize the influence of the reflected wave was prepared, and the effect of the resonance of the model system was minimized during the model tests. After the basic tests, the main model tests were conducted. Through the proposed main test, the quantitative magnitude of additional dynamic loads caused by machine vibration on a shallow foundation for machine on medium dense sand foundations were evaluated. From the results of the model test, the feasibility of design applied at home and abroad was reviewed.

키워드

참고문헌

  1. Arya, S.C., O'Neill, M.W., and Pincus, G. (1984), "Design of Structures and Foundations for Vibrating Machines", Gulf Publishing Company, Houston, Texas.
  2. Baidya, D.K. and Muralikrishna, G. (2001), "Natural Frequency of Vibrating Foundations on Layered Soil System-An Experimental Investigation", International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, Paper No.2.02.
  3. Bhowmik, D., Baidya, D.K., and Dasgupta, S.P. (2016), "A Numerical and Experimental Study of Hollow Steel Pile in Layered Soil Subjected to Vertical Dynamic Loading", Soil Dynamics and Earthquake Engineering, 85, pp.161-165. https://doi.org/10.1016/j.soildyn.2016.03.017
  4. Boominathan, A. and Lakshmi, T. (2000), "Dynamic Characteristics of Pile Group under Vertical Vibration", The 12th World Conference on Earthquake Engineering, pp.1-8.
  5. Ha, I.S. and Han, J.T. (2016), "Evaluation of the Allowable Axial Bearing Capacity of a Single Pile Subjected to Machine Vibration by Numerical Analysis", International Journal of Geo-Engineering, Vol.7, No.1, 22, pp.1-12.
  6. Han, J.T., Kwon, S.Y., Ha, I.S., and Kim, U.G. (2013), "Evaluation on Bearing Capacity for Machine Foundation in Plant considering Dynamic Load", The 39th Conference Proceedings of the Korean Society of Civil Engineers, KSCE, pp.2775-2778 (in Korean).
  7. KGS (2018), Manual of Foundation Design Criteria, Korean Geotechnical Society, pp.863-892 (in Korean).
  8. Korea Institute of Construction Technology (2014), "Development of Evaluation Technology on Bearing Capacity of Foundation for Vibrating Machines in Plant", Research Report, KICT (in Korean).
  9. Lee, J.S. (2014), "Estimation on 3-D Numerical Modeling of a Floasting Single Pile subjected to Machine Vibration", Master's Thesis, Kyungnam University (in Korean).
  10. Manna, B. and Baidya, D.K. (2010), "Dynamic Nonlinear Response of Pile Foundations under Vertical Vibration-theory Versus Experiment", Soil Dynamics and Earthquake Engineering, 30(6), pp.456-469. https://doi.org/10.1016/j.soildyn.2010.01.002
  11. Novak, M. and F. Grigg, R. (1976), "Dynamic Experiments with Small Pile Foundations", Canadian Geotechnical Journal, Vol.13, No.4, pp.372-385. https://doi.org/10.1139/t76-039