Increasing the Bearing Capacity of Shallow Foundations on Soft Soil After the Installation of Micro-Piles
Abstract
The bearing capacity of shallow foundations on soft soils can generally be estimated based on Local Shear Failure (Terzaghi theory). Several researchers previously stated that the installation of micro-piles on the failure area (slide) can increase the shear strength of the soil. This can be followed up by providing micro-pile reinforcement to prevent lateral soil movement. Therefore, this research was conducted to increase the bearing capacity of shallow foundations on medium-consistency soft clay soils that have been reinforced with micro piles. The research was conducted using modeling in the laboratory with a scale of 1:30. The soil sample used was kaolin clay made from slurry made from kaolin powder with a water content (wc = 1.77 LL), liquid limit (LL = 62.35%) and sample diameter (d = 33 cm). The slurry was formed by compacting at a medium consistency level with an undrained cohesion value (cu = 0.397 kg cm-2). The micro-pile material in the form of apus bamboo was installed, varying in diameter (d) 0.2 cm (0.027 B), 0.3 cm (0.04 B), and 0.5 cm (0.07 B); sum (n) 4, 9, 16, and 25; and length (L) 10 cm (1.33B), 13 cm (1.73B), and 16 cm (2.13B) micro-piles. While the foundation model uses a squarefoundation B x B with B = 7.5 cm. The tests were carried out before and after the micro-piles were reinforced with a soil shear failure test. The results showed that a decrease of 0.1B caused an increase in the ultimate bearing capacity of the micro-pile (qult-empirical, 0.1B) from the ultimate bearing capacity before installing the micro-pile. This value is then used to determine the ultimate bearing capacity ratio so that Rq,0.1B = qult-empirical,0.1B/qult-Terzaghiwith the optimum bearing capacity ratio occurring at Rq,0.1Bwith n3 = 16, d2 = 0.04B, L2= 1.73B.
References
Alfani, A. A., Sugianto, D. N., Indrayanti, E., Ismunarti, D. H. and Widiaratih, R. (2022), âModel fisik pengaruh armour cylinder concrete pada vertical breakwater terhadap koefisien refleksi gelombangâ, Indonesian Journal of Oceanography 4(1), 23â35.
Alnuaim, A. M., El Naggar, M. H. and El Naggar, H. (2016), âNumerical investigation of the performance of micropiled rafts in sandâ, Computers and Geotechnics 77, 91â105.
Ardana, I. M. D. (1999), âEffect of effective overburden stress and soil plasticity on the shear strength of undrained very soft consistency clayâ.
Bahtiar, E. T., Imanullah, A. P., Hermawan, D., Nugroho, N. et al. (2019), âStructural grading of three sympodial bamboo culms (hitam, andong, and tali) subjected to axial compressive loadâ, Engineering Structures 181, 233â245.
Brown (1994), Engineering and Design Bearing Capacity of Soils, ASCE, ASCE 1992, Departement of the army-Washington, DC 20314-100.
Cao, X. D., Wong, I. H. and Chang, M.-F. (2004), âBehavior of model rafts resting on pile-reinforced sandâ, Journal of geotechnical and geoenvironmental engineering 130(2), 129â138.
Das, B. M. (2010), Principles of Geotechnical Engineering, 7th edn, 200 First Stamford Place, Suite 400, USA.
DM-7, N. (1971), Design Manual, Soil Mechanics, Foundation and Earth.
El Sawwaf, M. (2010), âExperimental study of eccentrically loaded raft with connected and unconnected short pilesâ, Journal of geotechnical and geoenvironmental engineering 136(10), 1394â1402.
Eslami, A., Veiskarami, M. and Eslami, M. (2012), âStudy on optimized piled-raft foundations (prf) performance with connected and non-connected piles-three case historiesâ, International Journal of Civil Engineering 10(2), 100â111.
Esmaeilpour, P., Mamazizi, A. and Madabhushi, G.S. P. (2023), âAn overview of the model container types in physical modeling of geotechnical problemsâ, Soil Dynamics and Earthquake Engineering 168, 107827.
Hasheminezhad, A. and Bahadori, H. (2022), âOn the deep soil mixing method in the mitigation of liquefaction-induced bearing capacity degradation of shallow foundationsâ, Geomechanics and Geoengineering 17(1), 334â346.
Isnaniati (2017), âContribution of the shape of the pile to the maximum load received by the foundation for foundation planning on clay with surabaya cpt dataâ, aggregate journal 2(1), 21â27.
Lambe, T. W. and Whitman, R. V. (1969), âSoil mechanics. john willey & sonsâ, Inc., New York 553.
Manik, P., Yudo, H. and Siahaan, F. A. (2017), âPengaruh susunan dan ukuran bilah bambu petung (dendrocalamus asper) dan bambu apus (gigantochloa apus) terhadap kekuatan tarik, kekuatan tekan dan kekuatan lentur untuk komponen konstruksi kapalâ, Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan 14(3), 94â101.
Mochtar, N. E. (n.d.), âSoil improvementâ. Available at: https://scholar.google.com/scholar?hl=en&as_sdt=0,5&cluster=2757870835937004426.
Nasional, B. S. (2017), âSNI 8460-2017â, Persyaratan perancangan geoteknik.
Park, H.-J., Ko, K.-W., Song, Y.-H., Song, M.-J., Jin, S., Ha, J.-G. and Kim, D.-S. (2020), âCentrifuge modeling of disconnected piled raft using vertical pushover testsâ, Acta Geotechnica 15, 2637-2648.
Reul, O. and Randolph, M. F. (2004), âDesign strategies for piled rafts subjected to nonuniform vertical loadingâ, Journal of Geotechnical and Geoenvironmental Engineering 130(1), 1â13.
Rusdiansyah, I. B. M. and Mochtar, N. E. (2015), âEffect of burrow depth, spacing, and number of micro-piles in increasing the shear resistance of soft soil based on laboratory modelingâ.
Rusdiansyah, I. B. M. and Mochtar, N. E. (2016), âStudy on the increment of shear resistance of soft soil due to vertical piles reinforcement based on modeling in laboratoryâ, International Journal of Applied Engineering Research 11(8), 5934â5942.
Shah, I. A., Zaid, M., Farooqi, M. A. and Ali, K. (2021), âNumerical study on micropile stabilized foundation in flyashâ, Indian Geotechnical Journal 51(5), 1099â1106.
Suroso, H. M. (2008), âAlternative for reinforcement soft clay soil using micro-piles with variations in length and diameter of micro-pilesâ, Jurnal Rekayasa Sipil 2(1), 47â61.
Suroso, M. H. (2010), âThe effect of wooden pile and bamboo slice on the bearing capacity of soft claysâ, Journal of Civil Engineering 4(3), 161â174.
Terzaghi, K., Peck, R. B. and Mesri, G. (1996), Soil mechanics in engineering practice, John wiley & sons.
Tsukada, Y., Miura, K., Tsubokawa, Y., Otani, Y. and You, G.-L. (2006), âMechanism of bearing capacity of spread footings reinforced with micropilesâ, Soils and foundations 46(3), 367â376.
Umum, K. P. and Rakyat, P. (2019), âKumpulan korelasi parameter geoteknik dan fondasiâ, Kementerian Pekerjaan Umum dan Perumahan Rakyat. Jakarta.
Wen, L., Kong, G., Abuel-Naga, H., Li, Q. and Zhang, Z. (2020), âRectification of tilted transmission tower using micropile underpinning methodâ, Journal of Performance of Constructed Facilities 34(1), 04019110.
Ye, F. and Fu, W. P. D. (2018), âNo titleâ, Journal of Materials in Civil Engineering 30. Physical and Mechanical Characterization of Fresh Bamboo for Infrastructure Projects.
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