Simplified analytical solution for stress concentration ratio of piled embankments incorporating pile–soil interaction

Abstract

Piled embankments have been extensively used for high-speed rail over soft soils because of their effectiveness in minimizing differential settlement and shortening the construction period. Stress concentration ratio, defined as the ratio of vertical stress carried by pile heads (or pile caps if applicable) to that by adjacent soils, is a fundamental parameter in the design of piled embankments. In view of the complicated load transfer mechanism in the framework of embankment system, this paper presents a simplified analytical solution for the stress concentration ratio of rigid pile-supported embankments. In the derivation, the effects of cushion stiffness, pile–soil interaction, and pile penetration behavior are considered and examined. A modified linearly elastic-perfectly plastic model was used to analyze the mechanical response of a rigid pile–soil system. The analytical model was verified against field data and the results of numerical simulations from the literature. According to the proposed method, the skin friction distribution, pile–soil relative displacement, location of neural point, and differential settlement between the pile head (or cap) and adjacent soils can be determined. This work serves as a fast algorithm for initial and reasonable approximation of stress concentration ratio on the design aspects of piled embankments.

Keywords

Piled embankments / Pile–soil interaction / Pile penetration / Cushion / Rigid pile / High-speed railway

References

[1.] Bian X Li W Hu J Liu H Duan X Chen Y. Geodynamics of high-speed railway. Transp Geotech, 2018 17 69-76

[2.] Zhou M Liu H Chen Y Hu Y. First application of cast-in-place concrete large-diameter pipe (PCC) pile-reinforced railway foundation: a field study. Can Geotech J, 2016 53 708-16

[3.] Zhou S Wang B Shan Y. Review of research on high-speed railway subgrade settlement in soft soil area. Railw Eng Sci, 2020 28 129-145

[4.] Zheng G Jiang Y Han J Liu Y. Performance of Cement-fly Ash-gravel Pile-supported High-speed Railway embankments over soft marine clay. Mar Georesources Geotechnol, 2011 29 145-61

[5.] Wang C Xu Y Dong P. Working characteristics of concrete-cored deep cement mixingpiles under embankments. J Zhejiang Univ Sci A, 2014 15 419-31

[6.] Wu L Jiang G Ju N. Behavior and numerical evaluation of cement-fly ash-gravel pile-supported embankments over completely decomposed granite soils. Int J Geomech, 2019 19 04019048

[7.] Zhuang Y Cui X. Case studies of reinforced piled High-speed railway embankment over soft soils. Int J Geomech, 2016 16 06015005

[8.] Chen R Chen Y Han J Xu Z. A theoretical solution for pile-supported embankments on soft soils under one-dimensional compression. Can Geotech J, 2008 45 611-623

[9.] Han J Gabr MA. Numerical analysis of geosyntheticreinforced and pile-supported earth platforms over soft soil. J Geotech Geoenvironm Eng, 2002 128 44-53

[10.] Nunez MA Briançon L Dias D. Analyses of a pilesupported embankment over soft clay: full-scale experiment, analytical and numerical approaches. Eng Geol, 2013 153 53-67

[11.] Ariyarathne P Liyanapathirana DS. Review of existing design methods for geosynthetic-reinforced pile-supported embankments. Soils Found, 2015 55 17-34

[12.] van Eekelen SJM Bezuijen A van Tol AF. An analytical model for arching in piled embankments. Geotext Geomembran, 2013 39 78-102

[13.] van Eekelen SJM Bezuijen A van Tol AF. Validation of analytical models for the design of basal reinforced piled embankments. Geotext Geomembran, 2015 43 56-81

[14.] Hewlett WJ Randolph MF. Analysis of piled embankments. Gr Eng, 1988 21 12-8

[15.] Raithel M Kirchner A Kempfert HG. Li G Chen Y Tang X. German recommendations for reinforced embankments on pile-similar elements. Geosynthetics in Civil and Environmental Engineering, 2008 Berlin Springer

[16.] McGuire M (2011) Critical height and surface deformation of column-supported embankments. Dissertation,Virginia Polytechnic Institute and State University

[17.] Russell D Pierpoint N. An assessment of design methods for piled embankments. Gr Eng, 1997 30 39-44

[18.] Collin JG (2004) Column supported embankment design considerations.In: 52nd Annual Geotechnical Engineering Conference. University of Minnesota, Minneapolis, MN, USA, pp. 51–78

[19.] Nordic Geotechnical Society. Nordic handbook reinforced soils and fills, 2002 Stockholm, Sweden Nordic Geotechnical Society

[20.] Zhuang Y Wang K. Finite element analysis on the dynamic behavior of soil arching effect in piled embankment. Transp Geotech, 2018 14 8-21

[21.] Liu W Qu S Zhang H Nie Z. An integrated method for analyzing load transfer in geosynthetic-reinforced and pile-supported embankment. KSCE J Civ Eng, 2017 21 687-702

[22.] Miao L Wang F Lv W. A simplified calculation method for stress concentration ratio of composite foundation with rigid piles. KSCE J Civ Eng, 2018 22 3263-70

[23.] Zhuang Y Wang K. Analytical solution for reinforced piled embankments on elastoplastic consolidated soil. Int J Geomech, 2017 17 06017010

[24.] Luo Q Lu Q. Settlement calculation of rigid pile composite foundation considering pile-soil relative slip under embankment load. China J Highw Transp, 2018 31 20-30

[25.] Abusharar SW Zheng J Chen B Yin J. A simplified method for analysis of a piled embankment reinforced with geosynthetics. Geotext Geomembran, 2009 27 39-52

[26.] Pham TA. Analysis of geosynthetic-reinforced pile-supported embankment with soil-structure interaction models. Comput Geotech, 2020 121 103438

[27.] Matyas E Santamarina JC. Negative skin friction and the neutral plane. Can Geotech J, 1994 31 591-7

[28.] Zhou W Chen R Zhao L Xu Z Chen Y. A semi-analytical method for the analysis of pile-supported embankments. J Zhejiang Univ Sci A, 2012 13 888-94

[29.] Randolph MF Wroth CP. Analysis of vertical deformation of Pile groups. Géotechnique, 1979 29 423-39

[30.] Cao W Wang J Luo Z Zhai Y. Settlement calculation method for composite ground considering pile-soil slip under flexible foundation. China J Highw Transp, 2012 25 9-16

[31.] Evgine E Fakharian K. Effect of stress paths on the behaviour of sand-steel interfaces. Can Geotech J, 1996 33 853-65

[32.] Zhang S Zhao M He L. Calculation of settlement of composite foundation with rigid piles under flexible ground. J Highw Transp Res Dev English Ed, 2011 5 15-21

[33.] Lee J Park D Choi K. Analysis of load sharing behavior for piled rafts using normalized load response model. Comput Geotech, 2014 57 65-74

[34.] Mandy K Robert JM Frits AF. Pile-soil interaction and settlement effects induced by deep excavations. J Geotech Geoenvironm Eng, 2016 142 04016034

[35.] Yin Z Zhu H Xu G. A study of deformation in the interface between soil and concrete. Comput Geotech, 1995 17 75-92

[36.] Potyondy JG. Skin friction between various soils and construction materials. Géotechnique, 1961 11 339-53

[37.] Pham HTV, Suleiman MT, White DJ (2004) Numerical analysis of geosynthetic-rammed aggregate pier supported embankments. GeoTrans 2004, ASCE, Los Angeles, p. 657–664

[38.] Chen R Wang Y Ye X Bian X Dong X. Tensile force of geogrids embedded in pile-supported reinforced embankment: a full-scale experimental study. Geotext Geomembran, 2016 44 157-69

[39.] SJM Eekelen van (2019) The Dutch design guideline basal reinforced piled embankments, and the development and validation of its design methods Fifteenth International Conference on Structural and Geotechnical Engineering, Cairo, Egypt, 2019. p. 1–17

[40.] Balaam NP, Poulos HG, Brown PT (1977) Settlementanalysis of soft clays reinforced with granular piles. In: 5th Southeast Asian Conference on Soil Engineering, Bangkok, Thailand, 1977, p. 81–92

[41.] Ambily AP Gandhi SR. Behavior of stone columns based on experimental and FEM analysis. J Geotech Geoenvironm Eng, 2007 133 405-15

[42.] Balaam NP Booker JP. Analysis of rigid rafts supported by granular piles. Int J Numer Anal Methods Geomech, 1981 5 379-403

[43.] Zhao M He L Zhang L. Settlement calculation of CFG pile composite foundation based on load transfer method. Rock Soil Mech, 2010 31 839-44

[44.] Zhang C Jiang G Liu X Buzzi O. Arching in geogrid-reinforced pile-supported embankments over silty clay of medium compressibility: field data and analytical solution. Comput Geotech, 2016 77 11-25

[45.] Mayne PW Kulhawy FH. K0-OCR relationship in soil. J Geotech Engrg Div, 1982 108 851-72

[46.] Hu L Pu J. Test and modeling of soil-structure interface. J Geotech Geoenvironm Eng, 2004 130 851-60

[47.] Shakir RR Zhu J. Behavior of compacted clay-concrete interface. Front Struct Civ Eng, 2009 3 85-92

[48.] Jason T Zachary J. Role of initial state, material properties, and confinement condition on local and global soil-structure interface behavior. J Geotech Geoenvironm Eng, 2009 133 1646-60

[49.] Pra-Ai S Boulon M. Soil-structure cyclic direct shear tests: a new interpretation of the direct shear experiment and its application to a series of cyclic tests. Acta Geotech, 2017 12 107-27

[50.] Wu C Guo W Li Y Tie R. Calculation of neutral surface depth and pile-soil stress ratio of rigid pile composite foundation considering influence of negative friction. Chinese J Geotech Eng, 2016 38 278-87(in Chinese)

[51.] German Geotechnical Society (2010) Empfehlungen für den entwurf und die berechnung von erdkörpern mit bewehrungen aus geokunststoffen– EBGEO (Recommendation for design and analysis of earth structures using geosynthetic reinforcements). Ernst Sohn Berline. (in German)

Funding

National Natural Science Foundation of China(41901073); Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety(R202003); China Postdoctoral Science Foundation(2019M663556)