Modified p-y Curves Method Based on Degradation Stiffness Model of Sand

doi:10.16183/j.cnki.jsjtu.2019.094

Abstract

Abstract:

Most of the existing p-y curves are based on the model test results of small-diameter pile under cyclic loading of finite times, which makes it difficult to accurately describe the displacement accumulation of large-diameter pile under long-term horizontal cyclic loading and the cyclic weakening characteristics of soil. Therefore, based on the subroutine provided by Abaqus, a stiffness degradation model of the pile-soil system considering the long-term cyclic weakening effect of sand was established, and the p-y curves of large-diameter pile were obtained based on numerical analysis. Then, by introducing the concept of cyclic reaction ratio, the stiffness degradation factor of the pile-soil system was obtained, and the initial foundation reaction modulus was modified as well. Finally, a modified p-y curves method based on the degradation stiffness model of sand was proposed. By comparing with the test results, the validity of this method is verified. This modified p-y curves method, which is able to consider the effects of loading characteristics, number of cycles, cyclic weakening of sand stiffness, provides a concise and effective analysis method for the preliminary design of monopile foundation under long-term horizontal cyclic loading.

Key words: sand, monopile, degradation stiffness model, scale effect, cyclic loading, p-y curves

CLC Number:

TU473

HU Anfeng, NAN Bowen, CHEN Yuan, FU Peng. Modified p-y Curves Method Based on Degradation Stiffness Model of Sand[J]. Journal of Shanghai Jiao Tong University, 2020, 54(12): 1316-1323.

Figures/Tables 13

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D/m	L/m	ρ_p/(kg·m^－3)	ν_p	EI×10^－10/(N·m²)
4	50	3.00	0.3	5.67
5	50	1.95	0.3	5.67
6	50	1.35	0.3	5.67