Device for Load-Redistribution between Existing Piles and Underpinning Micropiles
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 150, Issue 12
Abstract
A micropile preloading method using bolt-fastening was studied to improve the constructability and economic feasibility of underpinning micropiles for the vertical expansion of a building with existing pile foundation. Due to the close distance between the existing piles and new micropiles, and the difference in their stiffness, precise control of preloading is required for the micropiles. A new preloading device was developed for this purpose. The laboratory test showed that for precise control of preloading, direct bolt-fastening (like the bolt connection for steel structures) was better than the typical hydraulic jacking method. The results of laboratory and onsite tests showed that the proposed preloading device adequately redistributed the bearing load between the existing piles and underpinning micropiles. Further load-redistribution was also possible by applying post-loading to the micropiles with continuous long-term measurement of bearing force whenever it was needed, even after the construction of the building expansion.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This work was supported by Daechi 2 Remodeling Housing Association. The authors are grateful to the authorities for their support. CLS ENG, KH Construction, JOOSHIN, and Korea Concrete Institute (KCI) collaborated in this work. The tests in this work were conducted with the assistance of the Institute of Construction and Environmental Engineering and Extreme Performance Testing Center and at Seoul National University.
References
Bhattacharjee, A., S. Mittal, and A. Krishna. 2011. “Bearing capacity improvement of square footing by micropiles.” Int. J. Geotech. Eng. 5 (1): 113–118. https://doi.org/10.3328/IJGE.2011.05.01.113-118.
Das, B. M. 2015. Principles of foundation engineering. Boston: Cengage Learning.
El Kamash, W., and J. Han. 2017. “Numerical analysis of existing foundations underpinned by micropiles.” Int. J. Geomech. 17 (6): 04016126. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000833.
Elsawwaf, A., M. El Sawwaf, A. Farouk, F. Aamer, and H. El Naggar. 2023. “Restoration of tilted buildings via micropile underpinning: A case study of a multistory building supported by a raft foundation.” Buildings 13 (2): 422. https://doi.org/10.3390/buildings13020422.
FHWA (Federal Highway Administration). 2005. Micropile design and construction. Washington, DC: National Highway Institute.
Han, J., and S. L. Ye. 2006. “A field study on the behavior of a foundation underpinned by micropiles.” Can. Geotech. J. 43 (1): 30–42. https://doi.org/10.1139/t05-087.
KGS (Korean Geotechnical Society). 2015. Commentary for foundation design code. Seoul: KGS.
Kim, D., J. Kim, and S. Jeong. 2019. “Estimation of axial stiffness on existing and reinforcing piles in vertical extension remodeled buildings.” Eng. Struct. 199 (Nov): 109466. https://doi.org/10.1016/j.engstruct.2019.109466.
KSCE (Korean Society of Civil Engineers). 2008. Korea highway design standard, explanation. Seoul: Korea Bridge Design & Engineering Research Center (KBRC), Kimoondang.
Larsson, K., and D. Jog. 2014. “Performance of micropiles used to underpin highway bridges.” J. Perform. Constr. Facil. 28 (3): 592–607. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000426.
Lopes, F. R., L. C. B. D’Hyppolito, F. A. B. Danziger, and L. B. Becker. 2020. “Settlements during underpinning with different processes: Case of a hospital in Rio de Janeiro, Brazil.” J. Geotech. Geoenviron. Eng. 146 (6): 05020003. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002266.
Makarchian, M., and H. G. Poulos. 1996. “Simplified method for design of underpinning piles.” J. Geotech. Eng. 122 (9): 745–751. https://doi.org/10.1061/(ASCE)0733-9410(1996)122:9(745).
Moradi Moghaddam, H., M. Keramati, A. Ramesh, and R. Naderi. 2021. “Experimental evaluation of the effects of structural parameters, installation methods and soil density on the micropile bearing capacity.” Int. J. Civ. Eng. 19 (May): 1313–1325. https://doi.org/10.1007/s40999-021-00629-5.
Poulos, H. G. 2001. “Piled raft foundations: Design and applications.” Géotechnique 51 (2): 95–113. https://doi.org/10.1680/geot.2001.51.2.95.
Wang, C., J. T. Han, and Y. E. Jang. 2019. “Experimental investigation of micropile stiffness affecting the underpinning of an existing foundation.” Appl. Sci. 9 (12).
Wang, C., J.-T. Han, and S. Kim. 2021. “A field study on the load sharing behavior of a micropiled raft underpinned by a waveform micropile.” Can. Geotech. J. 59 (7): 1175–1187. https://doi.org/10.1139/cgj-2020-0547.
Wang, C.-C., J.-T. Han, Y.-E. Jang, I.-S. Ha, and S.-J. Kim. 2018. “Study on the effectiveness of preloading method on reinforcement of the pile foundation by 3D FEM analysis.” J. Korean Geotech. Soc. 34 (1): 47–57. https://doi.org/10.7843/kgs.2018.34.1.47.
Wen, L., G. Kong, H. Abuel-Naga, Q. Li, and Z. Zhang. 2020. “Rectification of tilted transmission tower using micropile underpinning method.” J. Perform. Constr. Facil. 34 (1): 04019110. https://doi.org/10.1061/(ASCE)CF.1943-5509.0001398.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 150 • Issue 12 • December 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: Feb 1, 2024
Accepted: Jun 28, 2024
Published online: Oct 8, 2024
Published in print: Dec 1, 2024
Discussion open until: Mar 8, 2025
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.