Abstract
For a laterally loaded pile with its head keyed into the cap, pile head actually rotates in spite of the restraint of the cap. Being aware of this fact, some parameters were put forward to represent the degree of rotational restraint at pile top, and many calculation methods of lateral pile responses were then developed. However, the presented solutions are only for piles under pure lateral loads. In fact, they are usually under the vertical loads simultaneously, caused by the weights of themselves and superstructures. Besides, the slight initial inclination of pile shaft is inevitable in engineering. Some researchers raised solutions of lateral responses of the slightly inclined single pile under combined vertical and lateral loads, but the partially fixed-head condition and the elastoplasticity of soil were not considered. In this study, elastoplastic semi-analytical solutions of lateral responses of the slightly inclined single pile under combined vertical and lateral loads were deduced, in which the rotational restraint coefficient was used to represent the degree of rotational restraint at pile top, and the three-parameter model of the coefficient of subgrade reaction was employed. The computer program was developed thereafter. The effectiveness and advantage of the obtained solutions were validated by the comparison among existing solutions, presented solutions and model test results. Sensitivity analysis was carried out for parameters such as the initial inclination angle of pile shaft, the rotational restraint coefficient, and the vertical load. Eventually, effects of each parameter on lateral pile responses were presented and discussed.
Similar content being viewed by others
Abbreviations
- N p :
-
Vertical load (kN)
- Q p :
-
Horizontal load (kN)
- M p :
-
Bending moment at pile top (kN m)
- u p :
-
Horizontal displacement of pile shaft at pile head (mm)
- φ p :
-
Rotation angle of pile shaft at pile head (rad)
- θ :
-
Initial inclination angle of pile shaft (rad)
- \(u_{*}\) :
-
Yielding displacement of soil (mm)
- H 0, H 1, H 2 :
-
Pile length (m)
- H :
-
Total pile length (m)
- K m :
-
Rotational restraint coefficient (kN m/rad)
- q :
-
Distributed load acting on pile shaft above ground (kN/m)
- q 0, Δq :
-
Coefficient of distributed load acting on pile shaft above ground (kN/m)
- N G, N S, N E :
-
Axial force of pile shaft (kN)
- f 0, f 1 :
-
Coefficient of axial load of pile shaft (kN/m)
- \(u_{\text{G}}^{\text{t}}\), \(u_{\text{S} }^{\text{t}}\), \(u_{\text{E} }^{\text{t}}\) :
-
Abscissa value of longitudinal axis of pile shaft
- u G, u S, u E :
-
Horizontal displacement of pile shaft (mm)
- u free :
-
Horizontal displacement at pile top with free-head condition (mm)
- u vp :
-
Horizontal displacement at the top of the vertical pile (mm)
- \(\varphi_{\text{G}}\), \(\varphi_{\text{S}}\), \(\varphi_{\text{E}}\) :
-
Rotation angle of pile shaft (rad)
- \(M_{\text{G} }\), \(M_{\text{S}}\), \(M_{\text{E}}\) :
-
Bending moment of pile shaft (kN m)
- M max :
-
Maximum bending moment under ground (kN m)
- M fixed :
-
Bending moment at pile top with fixed-head condition (kN m)
- M vmax :
-
Maximum bending moment under ground of the vertical pile (kN m)
- \(Q_{\text{G} }\), \(Q_{\text{S}}\), \(Q_{\text{E}}\) :
-
Shear force of pile shaft (kN)
- p, p u :
-
Soil resistance (kN/m)
- b :
-
Pile width (m)
- k 0 :
-
Coefficient of soil resistance in plastic zone (kN/m3)
- k 1 :
-
Coefficient of subgrade reaction in elastic zone of soil (kN/m3)
- m :
-
Scale factor in coefficient of subgrade reaction (kN/m3+n)
- n :
-
Index in coefficient of subgrade reaction
- z 0 :
-
A parameter standing for soil resistance at ground level (m)
- z m :
-
Distance between maximum bending moment and pile top (m)
- EI :
-
Flexural stiffness of pile (kN m2)
- E :
-
Modulus of elasticity of pile (kPa)
- I :
-
Moment of inertia of pile cross section (m4)
References
Laora, R.D.; Rovithis, E.: Kinematic bending of fixed-head piles in nonhomogeneous soil. J. Geotech. Geoenviron. Eng. ASCE 141(4), 04014126 (2015)
Fayyazi, M.S.; Taiebat, M.; Finn, W.D.L.: Group reduction factors for analysis of laterally loaded pile groups. Can. Geotech. J. 51(7), 758–769 (2014)
Tehrani, F.S.; Prezzi, M.; Salgado, R.: A multidirectional semi-analytical method for analysis of laterally loaded pile groups in multi-layered elastic strata. Int. J. Numer. Anal. Met. 40(12), 1730–1757 (2016)
Mokwa, R.L.; Duncan, J.M.: Rotational restraint of pile caps during lateral loading. J. Geotech. Geoenviron. Eng. ASCE 129(9), 829–837 (2003)
Prakash, S.; Sharma, H.D.: Pile Foundations in Engineering Practice. Wiley, New York (1990)
Jiang, L.H.; Kong, L.G.; Lin, G.; Chen, Y.M.: Simplified method of laterally loaded single piles with partial pile head fixity. Eng. Mech. 31(11), 63–69 (2014). (in Chinese)
Kong, L.G.; Jiang, L.H.; Chen, R.P.; Chen, Y.M.: Response of single pile with partial pile head fixity subjected to lateral loading. Chin. J. Appl. Mech. 31(3), 393–399 (2014). (in Chinese)
Chatterjee, K.; Choudhury, D.; Poulos, H.G.: Seismic analysis of laterally loaded pile under influence of vertical loading using finite element method. Comput. Geotech. 67(6), 172–186 (2015)
Zhang, L.; Gong, X.N.; Yu, J.L.: Elastic solutions for partially embedded single piles subjected to simultaneous axial and lateral loading. J. Cent. South Univ. 21(11), 4330–4337 (2014)
Hirai, H.: A winkler model approach for vertically and laterally loaded piles in nonhomogeneous soil. Int. J. Numer. Anal. Methods Geomech. 36(17), 1869–1897 (2012)
Liang, F.Y.; Chen, H.B.; Chen, S.L.: Influences of axial load on the lateral response of single pile with integral equation method. Int. J. Numer. Anal. Methods Geomech. 36(16), 1831–1845 (2012)
Zhang, L.; Zhao, M.H.; Zhao, H.: Transfer matrix method for deformation of pile type bridge pier under axial transverse load. China J. Highw. Transp. 28(2), 69–76 (2015). (in Chinese)
Gabr, M.A.; Wang, J.J.; Zhao, M.: Buckling of piles with general power distribution of lateral subgrade reaction. J. Geotech. Geoenviron. Eng. ASCE 123(2), 123–130 (1997)
Chen, R.B.; Lu, R.M.: Analysis and treatment of bearing capacity behavior of sloping prestressed pipe-pile. Chin. J. Rock Mech. Eng. 25(S2), 3545–3551 (2006). (in Chinese)
Zheng, G.; Li, S.; Du, Y.M.; Zhang, X.S.: Bearing capacity behaviors of inclined pile under vertical load. J. Tianjin Univ. 45(7), 567–576 (2012). (in Chinese)
Nadeem, M.; Chakraborty, T.; Matsagar, V.: Nonlinear buckling analysis of slender piles with geometric imperfections. J. Geotech. Geoenviron. Eng. ASCE 141(1), 06014014 (2015)
Li, W.Z.; Zhao, M.H.; Shan, Y.M.; Yang, M.H.: Analysis of single pile under eccentric and inclined loading. Cent. South Highw. Eng. 30(3), 53–57 (2005). (in Chinese)
Zhao, M.H.; Li, W.Z.; Shan, Y.M.; Yang, M.H.: Behavior analysis of piles in layered clays under eccentric and inclined loads by improved finite pole element method. Eng. Mech. 25(5), 79–84 (2008). (in Chinese)
Zhao, M.H.; Li, W.Z.; Yang, M.H.; Shan, Y.M.: A model test study on displacement of piles under inclined and eccentric loads in layered soils. China Civ. Eng. J. 39(12), 95–99 (2006). (in Chinese)
Hsiung, Y.M.; Chen, S.S.; Chou, Y.C.: Analytical solution for piles supporting combined lateral loads. J. Geotech. Geoenviron. Eng. ASCE 132(10), 1315–1324 (2006)
Guo, W.D.: Nonlinear response of laterally loaded piles and pile groups. Int. J. Numer. Anal. Met. 33(7), 879–914 (2009)
Zhang, L.; Gong, X.N.; Yu, J.L.: Semi-analytical solutions for single piles subjected to combined vertical and lateral loads by subgrade reaction method. J. Harbin Inst. Technol. 43(6), 96–100 (2011). (in Chinese)
Zheng, G.; Wang, L.: Finite element analysis of bearing capacity of pile under inclined load in layered soil. Rock Soil Mech. 30(3), 680–687 (2009). (in Chinese)
Acknowledgements
This work was funded by the National Natural Science Foundation of China (Grant No. 51508455), and the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2019JM-232).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhang, L. Lateral Bearing Behaviors of Slightly Inclined Single Pile with Different Pile Head Restraint Under Combined Loads. Arab J Sci Eng 46, 4593–4602 (2021). https://doi.org/10.1007/s13369-020-05026-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13369-020-05026-z