Structure nonlinearity and response of laterally loaded piles

Authors

Wei Dong Guo, University of WollongongFollow
B T. Zhu, Arup Pty Ltd, Furtitude Valley, Qld

RIS ID

39266

Publication Details

Guo, W. Dong. Zhu, B. T. (2011). Structure nonlinearity and response of laterally loaded piles. Australian Geomechanics Journal, 46 (3), 41-52.

Abstract

In light of a generic limiting force profile (LFP), closed·form solutions for laterally loaded free- and fixed- head piles in elastic-plastic media have been developed, and implemented by the first author into a spreadsheet program called GASLFP. The solutions offer an expeditious and sufficiently accurate prediction of response of lateral piles. Conversely, they allow input parameters to be deduced using measured pile response, as has been conducted for over 70 test (elastic) piles to date. Nevertheless. structure nonlinearity of pile body is an important issue at a large deflection.

In this paper, a semi·empirical approach is established to capture pile response owing to structural nonlinearity. Expressions were provided for gaining cracking moment M_cr, flexural rigidity of cracked cross section E_pl_p. and ultimate bending moment M_ult Against measured response of two laterally loaded single piles, back-estimation indicates that (1) the parameters for elastic piles are quite consistent with the previous findings for piles in sand and clay, (2) The proposed variations of M_cr, E_pl_p and M_ult, for nonlinear piles provide good prediction of the pile response against measured data and (3) the modulus of rupture k_r of 16.7 (clay) and 33.0(sand) are close 10 those adopted for structural beams, although a very high k_r of 62.7 (thus resulting in higher M_cr, ) for a pi le in sand was deduced (shown elsewhere). The use of the k_r for beams would render pile deflections of the later pile to be significantly overestimated. The conclusions may be incorporated into design of laterally loaded piles.