Behavior of Piled Raft Foundation on Heterogeneous Clay Deposits Using Random Field Theory

Document Type : Research Papers

Authors

The University of Guilan

Abstract

In the case of problematic soils and tall buildings where the design requirements cannot be satisfied merely by a raft foundation, it is of common practice to improve the raft performance by adding a number of piles so that the ultimate load capacity and settlement behavior can be enhanced. In this study, the effect of spatial variability of soil parameters on the bearing capacity of piled raft foundation is investigated based on the random field theory using the finite difference software of FLAC3D. The coefficient of variation (COV) of the soil’s undrained shear strength, the ratio of standard deviation to the mean, was considered as a random variable. Moreover, the effect of variation of this parameter on the bearing capacity of piled raft foundation in undrained clayey soils was studied taking the Monte Carlo simulation approach and the normal statistical distribution. According to the results, taking into account the soil heterogeneity generally results in more contribution of the raft in bearing capacity than that of the homogenous soils obtained by experimental relationships, which implies the significance of carrying out stochastic analyses where the soil properties are intensively variant.

Keywords

Main Subjects

References

Adler, R.J. (2010). "The geometry of random fields", Society for Industrial and Applied Mathematics, SIAM edition.
Ahmed, A. and Soubra, A.H. (2012). "Probabilistic analysis of strip footings resting on a spatially random soil using subset simulation approach", Georisk, 6(3), 188–201.
Albusoda, B.S. and Salem L.A.K.  (2016). "The effect of interaction on pile-raft system settlement subjected to earthquake excitation", Applied Research Journal, 2(4), 205-214.
Bajad, S. and Sahu R.  (2008). "An experimental study on the behavior of vertically loaded piled raft on soft clay", The 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, India.
Baziar, M., Ghorbani A. and Katzenbach R. (2009). "Small-scale model test and three-dimensional analysis of pile-raft foundation on medium-dense sand", International Journal of Civil Engineering, 7(3), 170-175.
Bourgeois, E., De Buhan, P. and Hassen, G. (2012). "Settlement analysis of piled-raft foundations by means of a multiphase model accounting for soil-pile interactions", Computers and Geotechnics, 46, 26-38.
Ching, J. and Phoon, K.K. (2013). "Probability distribution for mobilized shear strengths of spatially variable soils under uniform stress states", Georisk, 7(3), 209–224.
Cho, J., Lee, J.H., Jeong, S. and Lee, J. (2012). "The settlement behavior of piled raft in clay soils", Ocean Engineering, 53, 153-163.
Dasaka, S.M. and Zhang, L.M. (2012). "Spatial variability of in situ weathered soil", Géotechnique, 62(5), 375-384.
DeGroot, D.J. (1996). "Analyzing spatial variability of in situ soil properties", Uncertainty in the Geologic Environment: From Theory to Practice, ASCE.
Elahi, A. (2011). "Evaluation of piled-raft bearing capacity located on heterogeneous soils using random field theory", M.Sc. Dissertation, University of Guilan, Rasht, Iran, (in Persian).
Fan, H., Huang, Q. and Liang, R. (2014). "Reliability analysis of piles in spatially varying soils considering multiple failure modes", Computers and Geotechnics, 57(Apr), 97-104.
Fleming, K., Weltman, A., Randolph, M. and Elson, K. (2008). Piling engineering, CRC press.
Griffiths, D. and Fenton G.A. (2001). "Bearing capacity of spatially random soil: The undrained clay prandtl problem revisited", Geotechnique, 51(4), 351-360.
Haldar, S. and Babu G.S. (2008a). "Reliability measures for pile foundations based on cone penetration test data", Canadian Geotechnical Journal, 45(12), 1699-1714.
Haldar, S. and Babu, G.S. (2008b). "Effect of soil spatial variability on the response of laterally loaded pile in undrained clay", Computers and Geotechnics, 35(4), 537-547.
Husain, A. (2016). "Probabilistic study for single pile in cohesionless soil Using Monte Carlo simulation technique", International Journal of Scientific and Engineering Research, 7(2). 628-633.
Itasca, F.D. (2009). "Fast Lagrangian analysis of continua in 3 dimensions, Version 4.0", Minneapolis, Minnesota, Itasca Consulting Group 438.
Jamshidi Chenari, R. and Mahigir, A. (2014). "The effect of spatial variability and anisotropy of soils on bearing capacity of shallow foundations", Civil Engineering Infrastructures Journal, 47(2), 199-213.
Jamshidi Chenari, R., and Alaie, R. (2015). "Effects of anisotropy in correlation structure on the stability of an undrained clay slope", Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 9(2), 109-123.
Jamshidi Chenari, R. and Behfar, B. (2017). "Stochastic Analysis of Seepage through Natural Alluvial Deposits Considering Mechanical Anisotropy", Civil Engineering Infrastructures Journal, 50(2), 233-253.
Jiang, S.H., Li, D.Q., Cao, Z.J., Zhou, C.B. and Phoon, K.K. (2014). "Efficient system reliability analysis of slope stability in spatially variable soils using Monte Carlo simulation", Journal of Geotechnical and Geoenvironmental Engineering, 141(2): 04014096.
Kalos, M.H. and Whitlock, P.A.  (2008). Monte Carlo methods, John Wiley & Sons.
Kenarsari, E., Oloomi, R., Jamshidi Chenari, R.  and Eslami, A. (2011). "Effect of vertical heterogeneity in soil strength on pile bearing capacity prediction from CPT data", Proceedings of the 36th Annual Conference on Deep Foundations, Boston, MA.
Lee, J., Kim, Y. and Jeong, S.  (2010). "Three-dimensional analysis of bearing behavior of piled raft on soft clay", Computers and Geotechnics, 37(1), 103-114.
Lee, J., Park, D. and Choi, K. (2014). "Analysis of load sharing behavior for piled rafts using normalized load response model", Computers and Geotechnics, 57, 65-74.
Lee, J., Park, D. and Park, K. (2015). "Estimation of load-sharing ratios for piled rafts in sands that includes interaction effects", Computers and Geotechnics, 63, 306-314.
Li, D.Q., Qi, X.H., Cao, Z.J., Tang, X.S., Phoon, K.K.  and Zhou, C.B.  (2016). "Evaluating slope stability uncertainty using coupled Markov chain", Computers and Geotechnics, 73: 72-82.
Li, M., Lu, X., Lu, X. and Ye, L. (2014). "Influence of soil–structure interaction on seismic collapse resistance of super-tall buildings", Journal of Rock Mechanics and Geotechnical Engineering, 6(5), 477-485.
Lloret-Cabot, M., Fenton, G.A. and Hicks, M.A. (2014). "On the estimation of scale of fluctuation in geostatistics", Georisk, 8(2), 129–140.
Matsuo, M. and Kuroda, K. (1974). "Probabilistic approach to design of embankments", Soils and Foundations, 14(2), 1-17.
Morse, R. (1971). "Importance of proper soil units for statistical analysis", Proceedings of the 1st  International Conference on Applications of Statistics and Probability to Soil and Structural Engineering, Hong Kong.
Nguyen, D.D.C., Jo, S.B. and Kim, D.S. (2013). "Design method of piled-raft foundations under vertical load considering interaction effects", Computers and Geotechnics, 47, 16-27.
Niandou, H. and Breysse, D. (2007). "Reliability analysis of a piled raft accounting for soil horizontal variability", Computers and Geotechnics, 34(2), 71-80.
Papadopoulos, C.E. and Yeung, H. (2001). “Uncertainty estimation and Monte Carlo simulation method”, Flow Measurement and Instrumentation, 12(4), 291-298.
Park, D., Park, D. and Lee, J. (2016). "Analyzing load response and load sharing behavior of piled rafts installed with driven piles in sands", Computers and Geotechnics, 78, 62-71.
Patil, J.D., Vasanwala, S.A. and Solanki, C.H. (2014). "An experimental investigation on behavior of piled raft foundation", International Journal of Geomatics and Geosciences, 5(2), 300.
Phoon, K.K. and Kulhawy, F.H. (1999). "Characterization of geotechnical variability", Canadian Geotechnical Journal, 36(4), 612-624.
Popescu, R., Deodatis, G. and Nobahar, A. (2005). "Effects of random heterogeneity of soil properties on bearing capacity", Probabilistic Engineering Mechanics, 20(4), 324-341.
Poulos, H. (2002). "Simplified design procedure for piled raft foundations", Deep Foundations 2002: An International Perspective on Theory, Design, Construction and Performance, pp: 441-458.
Poulos, H.G. and Davids, A.J. (2005). "Foundation design for the emirates twin towers, Dubai." Canadian Geotechnical Journal, 42(3), 716-730.
Randolph, M. (1992). "Design methods for pile groups and piled rafts", XIII ICSMFE, 61-82.
Reul, O. and Randolph M. (2003). "Piled rafts in overconsolidated clay: comparison of in situ measurements and numerical analyses", Geotechnique, 53(3), 301-315.
Reul, O. and Randolph, M.F. (2004). "Design strategies for piled rafts subjected to nonuniform vertical loading", Journal of Geotechnical and Geoenvironmental Engineering, 130(1), 1-13.
Saeedi Azizkandi, A. and Fakher, A. (2014). "A Simple Algorithm for Analyzing a Piled Raft by Considering Stress Distribution", Civil Engineering Infrastructures Journal, 47(2), 215-227.
Salgado, R., and Kim, D. (2014). "Reliability analysis of load and resistance factor design of slopes", Journal of Geotechnical and Geoenvironmental Engineering, 140(1),57-73.
Tung, Y.K. and Yen, B.C. (2005). Hydrosystems engineering uncertainty analysis, ASCE,McGraw Hill. 
Vanmarcke, E. (2010). Random fields: Analysis and synthesis, World Scientific.
Zhang, J., Zhang, L. and Tang, W.H.  (2011). "New methods for system reliability analysis of soil slopes", Canadian Geotechnical Journal, 48(7), 1138-1148.
Zhang, L., Goh, S.H.  and Yi, J. (2016). "A centrifuge study of the seismic response of pile-raft systems embedded in soft clay", Géotechnique, 67(6), 479-490.
 
Civil Engineering Infrastructures Journal
Volume 51, Issue 1
June 2018
Pages 35-54

Files

History

  • Receive Date: 25 April 2017
  • Revise Date: 20 February 2018
  • Accept Date: 01 May 2018

Share

How to cite

Statistics