Prediction of Piled Raft Settlement Using Soil Subgrade Modulus in Consolidating Clays
Publication: Practice Periodical on Structural Design and Construction
Volume 26, Issue 4
Abstract
Time-dependent settlements of piled raft foundations embedded in consolidating clays were studied using three-dimensional (3D) finite-element analysis and critical state-based soil constitutive modified Cam-Clay (MCC) model. In this study, different small to large rectangular rafts connected to circular bored cast-in-situ piles resting on four different types of clays and with varying overconsolidation ratios (OCRs) (1, 2, and 5) for each clay under a single drainage condition were analyzed. The influence of various piled raft parameters (pile length, pile spacing, pile diameter, raft thickness) and soil parameters (Poisson’s ratio of soil, soil critical state parameters, stress history of soil or OCR) on immediate and consolidation settlements of piled rafts were investigated. The detailed parametric study shows that critical state parameters and soil elastic properties have important roles in piled raft immediate and consolidation settlements. However, the pattern of parametric influence on immediate settlement and consolidation settlement is different. To capture the total settlement at the end of primary consolidation, a simple and quick calculation method for estimating the average soil subgrade modulus below the piled raft in consolidating clays is proposed through regression analysis and defining a combined influence parameter based on soil parameters, area ratio, and normalized loading. The results of the proposed method were compared with five case studies of piled raft foundations in various normally or overconsolidated clays showing satisfactory matches. It is believed that the proposed method will be very useful for design practitioners to get a quick estimate for the overall settlement of piled raft at the initial design stage.
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 codes that support the findings of this study are available from the corresponding author upon reasonable request:
•
Details of numerical analysis, and
•
Details of regression analysis.
References
Abdrabbo, F. M., and M. A. Mahmoud. 1990. “Correlations between index tests and compressibility of Egyptian clay.” Soils Found. 30 (2): 128–132. https://doi.org/10.3208/sandf1972.30.2_128.
Al-Mosawe, M. J., M. Y. Fattah, and A. A. O. Al-Zayadi. 2011. “Experimental observations on the behavior of a piled raft foundation.” J. Eng. 17 (4): 807–828.
Alnuaim, A. M., M. H. El Naggar, and H. El Naggar. 2015. “Performance of micropiled raft in clay subjected to vertical concentrated load: Centrifuge modeling.” Can. Geotech. J. 52 (12): 2017–2029. https://doi.org/10.1139/cgj-2014-0448.
Bajad, S. P., and R. B. Sahu. 2011. “Time dependent settlement of piled raft foundation.” In Proc., of Indian Geotechnical Conf., 225–228. Kochi, India: Indian Geotechnical Society.
Bhaduri, A., and D. Choudhury. 2020. “Serviceability-based finite-element approach on analyzing combined pile–raft foundation.” Int. J. Geomech. 20 (2): 04019178. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001580.
Bhartiya, P., T. Chakraborty, and D. Basu. 2020. “Settlement estimation of piled rafts for initial design.” J. Geotech. Geoenviron. Eng. 146 (2): 04019127. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002195.
Biot, M. A. 1941. “General theory of three-dimensional consolidation.” J. Appl. Phys. 12 (2): 155–164. https://doi.org/10.1063/1.1712886.
Bowles, J. E. 1996. Foundation analysis and design. 5th ed. New York: McGraw-Hill.
Butler, F. G. 1975. “Heavily over-consolidated clays: Review paper.” In Proc., Conf. on Settlements of Structures, 531–578. London: Pentech Press.
Chang, D.-W., W.-C. Lin, and C.-W. Lu. 2016. “Load and settlement of pile-raft foundation at post consolidation from 3D FEM analysis.” Jpn. Geotech. Soc. Spec. Publ. 2 (34): 1250–1254. https://doi.org/10.3208/jgssp.TWN-05.
Chen, S. L., and Y. N. Abousleiman. 2012. “Exact undrained elasto-plastic solution for cylindrical cavity expansion in modified Cam Clay soil.” Géotechnique 62 (5): 447–456. https://doi.org/10.1680/geot.11.P.027.
Cho, J., J.-H. Lee, S. Jeong, and J. Lee. 2012. “The settlement behavior of piled raft in clay soils.” Ocean Eng. 53 (Oct): 153–163. https://doi.org/10.1016/j.oceaneng.2012.06.003.
Clancy, P., and M. F. Randolph. 1993. “An approximate analysis procedure for piled raft foundations.” Int. J. Numer. Anal. Methods of Geomech. 17 (12): 849–869. https://doi.org/10.1002/nag.1610171203.
Colasanti, R. J., and J. S. Horvath. 2010. “Practical subgrade model for improved soil-structure interaction analysis: Software implementation.” Pract. Period. Struct. Des. Constr. 15 (4): 278–286. https://doi.org/10.1061/(ASCE)SC.1943-5576.0000060.
Cooke, R. W., D. F. Sillett, D. W. Bryden Smith, D. W. B. Smith, and M. V. Gooch. 1981. “Some observations of the foundation loading and settlement of a multi-storey building on a piled raft foundation in London clay.” Proc. Inst. Civ. Eng. 70 (3): 433–460. https://doi.org/10.1680/iicep.1981.1783.
de Sanctis, L., and G. Russo. 2008. “Analysis and performance of piled rafts designed using innovative criteria.” J. Geotech. Geoenviron. Eng. 134 (8): 1118–1128. https://doi.org/10.1061/(ASCE)1090-0241(2008)134:8(1118).
Dutta, S. C., and R. Roy. 2002. “A critical review on idealization and modeling for interaction among soil–foundation–structure system.” Comput. Struct. 80 (20–21): 1579–1594. https://doi.org/10.1016/S0045-7949(02)00115-3.
Fattah, M. Y., M. J. Al-Mosawe, and A. A. O. Al-Zayadi. 2013. “Time dependent behavior of piled raft foundation in clayey soil.” Geomech. Eng. 5 (1): 17–36. https://doi.org/10.12989/gae.2013.5.1.017.
Gasparre, A. 2005. “Advanced laboratory characterisation of London clay.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, Imperial College London.
Girija Vallabhan, C. V., W. Thomas Straughan, and Y. C. Das. 1991. “Refined model for analysis of plates on elastic foundations.” J. Eng. Mech. 117 (12): 2830–2844. https://doi.org/10.1061/(ASCE)0733-9399(1991)117:12(2830).
Hashash, Y. M. A., and A. J. Whittle. 1992. “Integration of the modified Cam-Clay model in non-linear finite element analysis.” Comput. Geotech. 14 (2): 59–83. https://doi.org/10.1016/0266-352X(92)90015-L.
Ho, I.-H., and C.-C. Hsieh. 2013. “Numerical modeling for undrained shear strength of clays subjected to different plasticity indexes.” J. Geoeng. 8 (3): 91–100. https://doi.org/10.6310/jog.2013.8(3).3.
Hooper, J. A. 1973. “Observations on the behaviour of a pile-raft foundation on London clay.” Proc. Inst. Civ. Eng. 55 (4): 855–877. https://doi.org/10.1680/iicep.1973.4144.
Horikoshi, K., and M. F. Randolph. 1996. “Centrifuge modelling of piled raft foundations on clay.” Géotechnique 46 (4): 741–752. https://doi.org/10.1680/geot.1996.46.4.741.
Huang, M., Y. Liu, and D. Sheng. 2011. “Simulation of yielding and stress–stain behavior of shanghai soft clay.” Comput. Geotech. 38 (3): 341–353. https://doi.org/10.1016/j.compgeo.2010.12.005.
Jain, S. K. 1985. “Analysis of the pressuremeter test by FEM formulation of the elasto-plastic consolidation.” Ph.D. thesis, Dept. of Civil Engineering, Virginia Tech.
Jain, V. K., M. Dixit, and R. Chitra. 2015. “Correlation of plasticity index and compression index of soil.” Int. J. Innovations Eng. Technol. 5 (3): 263–270.
Kirsch, A. 2011. “Analytical and numerical investigation of the subgrade modulus for raft and pile-raft-foundations.” In Proc., Calculation Methods in Geotechnics—Failure Mechanisms and Determination of Parameters, ÖGG-Tunnelbautag. Salzburg, Austria: Austrian Society for Geomechanics.
Koppula, S. D. 1981. “Statistical estimation of compression index.” Geotech. Test. J. ASTM 4 (2): 68–73.
Kordnaeij, A., F. Kalantary, B. Kordtabar, and H. Mola-Abasi. 2015. “Prediction of recompression index using GMDH-type neural network based on geotechnical soil properties.” Soils Found. 55 (6): 1335–1345. https://doi.org/10.1016/j.sandf.2015.10.001.
Lam, S. Y., C. W. W. Ng, and H. G. Poulos. 2013. “Shielding piles from downdrag in consolidating ground.” J. Geotech. Geoenviron. Eng. 139 (6): 956–968. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000764.
Lee, J., Y. Kim, and S. Jeong. 2010. “Three-dimensional analysis of bearing behavior of piled raft on soft clay.” Comput. Geotech. 37 (1–2): 103–114. https://doi.org/10.1016/j.compgeo.2009.07.009.
Lin, D.-G., W.-H. Chen, W.-T. Liu, and J.-C. Chou. 2017. “Parametric study of piled-raft foundation in deep excavation of Taipei metropolitan.” J. Mar. Sci. Technol. 25 (5): 508–519.
Lin, L. 1995. “Strength characteristics of a modelling silty clay.” M.Eng. thesis, Dept. of Engineering and Applied Science, Memorial Univ. of Newfoundland.
Liu, C., M. Yang, and A. Bezuijen. 2020. “Ratio of long-term settlement to immediate settlement for piled raft on soft clay.” Proc. Inst. Civ. Eng. Ground Improv. 173 (4): 216–223. https://doi.org/10.1680/jgrim.18.00048.
Loukidis, D. 2006. “Advanced constitutive modeling of sands and applications to foundation engineering.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, Purdue Univ.
Mendonca, A. V., and J. B. de Paiva. 2000. “A boundary element method for the static analysis of raft foundations on piles.” Eng. Anal. Boundary Elem. 24 (3): 237–247. https://doi.org/10.1016/S0955-7997(00)00002-3.
Mendonca, A. V., and J. B. Paiva. 2003. “An elastostatic FEM/BEM analysis of vertically loaded raft and piled raft foundation.” Eng. Anal. Boundary Elem. 27 (9): 919–933. https://doi.org/10.1016/S0955-7997(03)00061-4.
Mylonakis, G. 2001. “Winkler modulus for axially loaded piles.” Géotechnique 51 (5): 455–461. https://doi.org/10.1680/geot.2001.51.5.455.
Neville, A. M. 2011. Properties of concrete. London: Pearson.
Nguyen, D. D. C., S.-B. Jo, and D.-S. Kim. 2013. “Design method of piled-raft foundations under vertical load considering interaction effects.” Comput. Geotech. 47 (Jan): 16–27. https://doi.org/10.1016/j.compgeo.2012.06.007.
Papadimitriou, A. G., M. T. Manzari, and Y. F. Dafalias. 2005. “Calibration of a simple anisotropic plasticity model for soft clays.” In Soil Constitutive Models: Evaluation, Selection, and Calibration, Geotechnical Special Publication 128, edited by J. A. Yamamuro and V. N. Kaliakin, 415–424. Reston, VA: ASCE.
Poulos, H. G., and E. H. Davis. 1980. Pile foundation analysis and design. New York: Wiley.
Prakoso, W. A., and F. H. Kulhawy. 2001. “Contribution to piled raft foundation design.” J. Geotech. Geoenviron. Eng. 127 (1): 17–24. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:1(17).
Reul, O. 2000. “In-situ measurements and numerical studies on the bearing behaviour of piled rafts.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, Darmstadt Univ. of Technology.
Reul, O., and M. F. Randolph. 2004. “Design strategies for piled rafts subjected to nonuniform vertical loading.” J. Geotech. Geoenviron. Eng. 130 (1): 1–13. https://doi.org/10.1061/(ASCE)1090-0241(2004)130:1(1).
Rodriguez, E., R. P. Cunha, and B. Caicedo. 2018. “Behavior of piled raft foundation systems in soft soil with consolidation process.” In Vol. 2 of Proc., 9th Int. Conf. on Physical Modeling in Geotechnics, 1407–1411. London: CRC Press.
Roscoe, K. H., and J. B. Burland. 1968. “On the generalized stress strain behavior of wet clay.” In Engineering plasticity, 47–54. Cambridge, UK: Cambridge University Press.
Russo, G., and C. Viggiani. 1998. “Factors controlling soil-structure interaction for piled rafts.” In Proc., Int. Conf. on Soil-Structure Interaction, 297–321. Darmstadt, Germany: Darmstadt Univ. of Technology.
Schmidt, B. 1966. “Earth pressures at rest related to stress history.” Can. Geotech. J. 3 (4): 239–242. https://doi.org/10.1139/t66-028.
Sinha, A., and A. M. Hanna. 2017. “3D numerical model for piled raft foundation.” Int. J. Geomech. 17 (2): 04016055. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000674.
Small, J. C., and H. L. C. Liu. 2008. “Time-settlement behaviour of piled raft foundations using infinite elements.” Comput. Geotech. 35 (2): 187–195. https://doi.org/10.1016/j.compgeo.2007.04.004.
Sridharan, A., and H. B. Nagaraj. 2000. “Compressibility behaviour of remoulded, fine-grained soils and correlation with index properties.” Can. Geotech. J. 37 (3): 712–722. https://doi.org/10.1139/t99-128.
Vesic, A. B. 1961. “Beams on elastic subgrade and Winkler’s hypothesis.” In Proc., 5th Int. Conf. on Soil Mechanic and Foundation Engineering, 845–850. Paris: Dunod.
Winkler, E. 1867. Die Lehre Von Elasticitaet Und Festigkeit. 1st ed. Prague, Czech Republic: H. Dominicus.
Yamashita, K., M. Kakurai, and T. Yamada. 1994. “Investigation of a piled raft foundation on stiff clay.” In Proc., 13th Int. Conf. on Soil Mechanics and Foundation Engineering, 543–546. London: CRC Press.
Yu, H. S. 2006. Plasticity and geotechnics. New York: Springer.
Information & Authors
Information
Published In
Practice Periodical on Structural Design and Construction
Volume 26 • Issue 4 • November 2021
Copyright
© 2021 American Society of Civil Engineers.
History
Received: Dec 15, 2020
Accepted: Apr 27, 2021
Published online: Jul 30, 2021
Published in print: Nov 1, 2021
Discussion open until: Dec 30, 2021
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.
Cited by
- Priyanka Bhartiya, Dipanjan Basu, Tanusree Chakraborty, A simplified settlement prediction method for piled rafts in clay, Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, 10.1680/jgeen.21.00207, (1-20), (2022).
- Priyanka Bhartiya, Dipanjan Basu, Tanusree Chakraborty, Time-Dependent Response of Rectangular Piled Rafts in Clayey Soils, Journal of Geotechnical and Geoenvironmental Engineering, 10.1061/(ASCE)GT.1943-5606.0002758, 148, 5, (2022).
- Harpreet Singh, Aditya Kumar Tiwary, Analysis and effect of piles on raft foundation for High-Rise framed structure under seismic loading, Materials Today: Proceedings, 10.1016/j.matpr.2022.11.411, (2022).
- Victor Yavna, Vladimir Shapovalov, Maksim Okost, Andrey Morozov, Yakov Ermolov, Andrei Kochur, Modeling of long-term train loads impacts on subgrade soils: a review, International Journal of Transportation Science and Technology, 10.1016/j.ijtst.2022.06.005, (2022).