Model Test on Bearing Behaviors of Battered Piles under Horizontal Eccentric Loads

CAO Wei-ping; LI Qing-yuan; TAO Peng; ZHAO Min

doi:10.11988/ckyyb.20220430

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Journal of Changjiang River Scientific Research Institute ›› 2023, Vol. 40 ›› Issue (9) : 118-125. DOI: 10.11988/ckyyb.20220430

Rock-Soil Engineering

Model Test on Bearing Behaviors of Battered Piles under Horizontal Eccentric Loads

CAO Wei-ping^1,2, LI Qing-yuan¹, TAO Peng¹, ZHAO Min³

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Abstract

The bearing deformations of battered piles are intricate due to the asymmetrical stress field exerted by the self-weight of the surrounding soil. Model tests were conducted on battered piles embedded in sandy soils to investigate their bearing deformation behavior under horizontal eccentric loads perpendicular to their inclination direction. The study also revealed the effects of pile surface roughness and pile shaft inclination angle on the bearing deformation characteristics of battered piles, as well as the internal forces acting on the pile shaft. Test results manifest that under horizontal eccentric loads perpendicular to the inclined direction of battered piles, the horizontal displacement of the pile head is minimal, while torsional deformation is significant. The bearing capacity of battered piles primarily relies on their torsional bearing capacity. When a horizontally applied eccentric load is perpendicular to the pile’s inclination, the battered pile not only undergoes bending but also experiences tension along its longitudinal axis. The maximum bending moment induced in the battered pile shaft by the horizontal load exceeds the torque moment applied at the pile top by approximately 10% to 30%. The entire battered pile shaft is subjected to tension, although the tension is relatively small, with a maximum tensile force equal to around 5% of the horizontal load applied at the pile head. The pile shaft is also subjected to longitudinal and circumferential skin frictions. The upper shaft exhibits positive longitudinal skin friction, while the lower shaft exhibits negative friction, with the neutral point located at a depth of Z/L=0.3. The average longitudinal skin friction is considerably smaller than the average circumferential skin friction at the same depth.

Key words

battered pile / model test / torsional capacity / horizontal eccentric loads / longitudinal skin friction / circumferential skin friction

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CAO Wei-ping, LI Qing-yuan, TAO Peng, ZHAO Min. Model Test on Bearing Behaviors of Battered Piles under Horizontal Eccentric Loads[J]. Journal of Changjiang River Scientific Research Institute. 2023, 40(9): 118-125 https://doi.org/10.11988/ckyyb.20220430

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