Book Description

This dissertation, "Analysis and Prediction of the Axial Capacity and Settlement of Displacement Piles in Sandy Soil" by Feng, Mu, 牟峰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: ABSTRACT Piles are often used as foundations for tall buildings and critical structures. The performance of displacement piles in sand is recognized as being the area of greatest uncertainty in foundation design. Until recently, design methods throughout the world were almost entirely empirical. The failure to fully understand the underlying mechanisms is due mainly to the complexity of the interaction between the pile and surrounding soil. This thesis describes an investigation into the behavior of displacement piles in sandy soil and proposes a novel approach for the analysis and prediction of both the capacity and settlement of displacement piles under axial load. The estimation of ultimate base resistance is implemented in the framework of spherical cavity expansion theory by taking into account the properties of sandy soils, in terms of nonlinear shear stiffness and state-dependent shear strength. The ultimate local shaft friction is estimated based on a careful investigation of the 'friction fatigue' along the pile shaft during pile installation. Three phases of the load-settlement response are identified according to the mobilization of base and shaft resistances, and thereafter estimates are made in terms of the individual contributions of the base and shaft resistances to the total head settlement in each phase. A database of high-quality pile load tests is compiled for purposes of validating the proposed approach. A reasonably good agreement is shown between the measurements and predictions in both capacity and settlement. To facilitate the practical application, further effort has been made to develop a user-friendly software in the Windows platform that incorporates this novel approach. ii DOI: 10.5353/th_b3955898 Subjects: Piling (Civil engineering) Soil mechanics