DOI QR코드

DOI QR Code

근입조건에 따른 마이크로파일의 거동특성

Behavior Characteristics of Micropile Following the Embedded Condition

  • Bang, Seongtaek (Department of Construction & Disaster Prevention Engineering, Kyungpook National University)
  • 투고 : 2020.04.15
  • 심사 : 2020.05.28
  • 발행 : 2020.06.01

초록

최근 도심지 공사에 있어서는 공간부족 및 주변환경의 영향으로 기성파일의 시공이 불가능한 경우가 많다. 이러한 경우에 소형 장비로 시공이 가능하고 기존 파일의 지지능력을 발휘할 수 있는 소구경 파일 공법이 많이 사용되고 있다. 소구경 파일공법은 현장타설말뚝의 한 종류로서 파일의 직경이 75mm~300mm인 정도로 주변 구조물이나 지반 그리고 공간적인 장애물이 있는 경우에도 시공의 어려움이 거의 없으며 모든 종류의 토질조건에서 시공이 가능하다. 또한 시공과정에서 진동과 소음이 적고 건물 천장이 낮은 곳에서도 시공이 가능하므로 기존 건물의 기초보강에도 많이 이용된다. 이러한 마이크로파일이 압축력이나 인장력을 받았을 때 혹은 시공된 지반특성에 따라 변화되는 거동 특성에 대해서는 연구가 많지 않은 실정이다. 따라서 이 연구에서는 현장에 시공된 마이크로파일에 대한 현장재하시험 자료 분석을 통하여 마이크로 파일에 압축력 및 인장력을 가했을 경우 지반을 구성하는 성분과 파일의 근입조건에 따른 침하 및 지지력 특성을 규명하고 통계분석프로그램인 SAS를 활용하여 마이크로파일의 침하와 지지력에 영향을 미치는 주요한 인자에 대한 분석을 수행하였다.

In the recent downtown works, there are frequent cases where the work on existing piles is impossible due to the influence from lack of space and surrounding environment. In such cases, there has been growing cases of using the micropile method that is available to work with the small equipment and asserts the bearing capacity of the existing piles. The micropile method is a type of drilled shaft with the diameter of a pile to be around 75 mm~300 mm that, even for a case where it has certain surrounding structure, foundation and spatial obstacle, there is almost no work difficulty and the work is feasible under all types of soil conditions. In addition, the work can be done in places where the ceiling of the building is low with less vibration and noise in the work process that such method is significantly used for foundation reinforcement of existing buildings. With respect to the motion characteristics that are changed depending on the foundational characteristics or when the micropile is applied with compression or tensile force, there is very few studies conducted. Therefore, under this study, through the data analysis of the field loading test regarding the micropile worked in the fields, it clarifies the settlement and characteristics of bearing capacity following the embedded condition of the ingredients and piles that consist the foundation if the compression and tensile force are applied to the micropile, and by facilitating the statistical analysis program, SAS, to carry out the analysis on the main elements influencing on settlement of the micropile and bearing capacity.

키워드

참고문헌

  1. Abbs, A. F. (1984), A pile reinforced earth foundation for an oil stcrage tank, In-Situ Soil and Rock R einforcement, Paris, pp. 13-18.
  2. Gilloux, A. (1984), Evaluation de frottenment lateral soil, In-Situ Soil and Rock R einforcement Conference, Paris, pp. 66-70.
  3. Jang, Y. E. and Han, J. T. (2016), A field study on the constructability and performance evaluation of waveform micropile, Journal of the Korean Geotechnical Society, Vol. 32, No. 10, pp. 67-79 (In Korean). https://doi.org/10.7843/kgs.2016.32.10.67
  4. Jorge, G. R. (1969), The regroutable IRP anchorage for soft soil, low capacity or karstic rocks, Proceedings of the International Conference on Soil Mechanics and Foundation Engineering, Specialty Session No. 14 and 15, pp. 159-163.
  5. Korfiatis, G. P. (1984), Field testing of short pile system for floor sopport, In- Situ Soil and Rock Reinforcement Conference, Paris, pp. 71-75.
  6. Lee, M. S., Kim, M. I., Baek, J. N. and Han, B. G. (2011), Calculating the uniaxial compressive strength of granite from Gangwon province using linear regression analysis, The Journal of Engineering Geology, Vol. 21, No. 4, pp. 361-367 (In Korean). https://doi.org/10.9720/kseg.2011.21.4.361
  7. Lee, S. H. and Kim, Y. Y. (1996), Understanding small diameter pile micro pile, Journal of the Korean Society of Civil Engineers, Vol. 44, No. 7, pp. 48-54 (In Korean).
  8. Lee, S. M. and Baek, S. C. (2009), Estimation of the behavior of a micropile due to horizontal load, Journal of the Korean Geo-Environmental Society, Vol. 10, No. 6, pp. 117-123 (In Korean).
  9. Lizzi, F. (1978), Reticulated root piles to correct landslides, ASCE Convention, Chicago, pp. 23-31.
  10. Lizzi, F. (1983), The reticoldo Di Pali Radice (Reticulated Toot Piles) for the improvement of soil resitance, Physical Aspects and Design Approaches, Eighth European Conference on Soil Mechanics and Foundation Engineering, A. A. Balkema, Helsinki, pp. 521-524.
  11. Park, H. S., Baek, D. H., Do, J. U. and Lee, J. H. (2014), Examination of type and present state design on domestic small diameter piles", Krean Society of Civil Engineers, pp. 1621-1622 (In Korean).
  12. Plumelle, C. (1984), Amelioration de la portante d' un sol par inclusions de groupe et reseaux de micropieux, In-Situ Soil and Rock Reinforcement Conference, Paris, pp. 83-98.
  13. Prakash, S. (1990), Pile foundations in engineering practice, Printed by John Wiley and Sons, Inc., pp. 218-318.
  14. Weltman, A. (1981), A review of micro pile types, Ground Engineering, Vol. 14, No. 4, pp. 43-49.