Distribution characteristics of negative skin friction on piles installed at dredger fill sites considering consolidation effect

Abstract:

The paper aims to analyze the distribution of skin friction along piles caused by soil consolidation in newly formed dredger fill sites. Based on the continuous drainage boundary conditions and the ideal elastoplastic load transfer model, a theoretical model for the deformation analysis of pile foundations at newly filled sites was established considering the effect of soil consolidation. With the introduction of the continuous drainage boundary, the consolidation settlement of the double-layer foundation was acquired. The ideal elastoplastic load transfer method was used to simulate the pile shaft displacement-stress relationship, and the analytical solutions of skin friction and pile head settlement were obtained. Compared with experimental results, the proposed model was verified. The effects of time factor, thickness ratio of double-layer foundation, pile head load, and mechanics of pile foundation on axial force and skin friction were analyzed. Results show that as time increased, the negative skin friction increased and the neutral point of the skin friction moved downwards. When the thickness ratio of in-situ soil layer to new dredger fill layer increased, the negative skin friction decreased and the neutral point of the skin friction moved upwards. With the increase in the pile head load, the negative skin friction decreased and the neutral point moved upwards.