Analysis of pile load-transfer under pile-side softening

Abstract

A set of analytical equations for the variation of the axial force along depth and the pile-top load-settlement curve were established, using tri-linear softening model to pile-side soil and bilinear hardening model to pile-end soil. Influences of the pile-side and pile-end soil behavior on the load-settlement curve were discussed, indicating that the lowering reason for the variation step degree of the axial force along depth is the softening of the pile-side soil to result in the side friction lowering when the pile-top load is increased. To verify the reliability of this method, the parameters used in calculation are obtained from the test in Zhuzhou area. The obtained results are then compared with the tested results. Contrast shows that the calculated results and the tested values are very close, which illustrates that the proposed method is reliable.

Keywords

load-settlement curve / tri-linear softening model / bilinear hardening model

References

[1] ChenLong-zhu, LiangGuo-qian, ZhuJin-ying. Analytical calculation method of the axial load-settlement curve for piles[J]. Chinese Journal of Geotechnical Engineering, 1994, 16(6): 30-38(in Chinese)

[2] SeedH B, ReeseL C. The action of soft clay along friction pile[J]. Trans ASCE, 1995, 122: 731-754

[3] Kezdi A. The bearing capacity of pile and pile groups [A]. Proc 4th Int Conf S M & F E[C]. New York, 1957. 46–51.

[4] KraftL M, RayR P, KagawaT. Theoretical t-z Curves[J]. Journal Geotechnique Engineering Division, ASCE, 1981, 107(11): 1543-1561

[5] DuShao-jun, LingLi-chuan. Study of the numerical value calculation method for single pile load-settlement curve[J]. Journal of Central South University of Technology, 1998, 29(2): 120-122(in Chinese)

[6] PoulosH G, DavisE HPile foundation analysis and design[M], 1980, New York, John Wiley & Sons

[7] PrevostJ H, HughesT J R. Finite element solution of elastic-plastic boundary value problems [J]. Journal of Applied Mechanics, 1984, 48: 68-76

[8] SHEN Zhu-jiang. A few of problems of deformation calculation for strain softening material[J]. Jiangsu Mechanics(in Chinese), 1982, (6): 1–4.