Combined Pile Raft Foundations

This book presents the fundamental features of the design and performance of combined pile-raft foundations (CPRFs). Whereas in a traditional foundation the loads are carried either by the raft or by the piles, the capacity of CPRFs is assessed for the foundation as a whole, reducing total and differential settlements economically. The five chapters provide an overview of the historical development of piled rafts in practice and research, and of the design concepts developed for piled rafts over the last decades. Fundamental aspects of their bearing behaviour are presented, as well as an overview of the framework of the design process for CPRFs, including the safety concept, the design approach summarised in the ISSMGE Combined Pile-Raft Foundation Guideline (ISSMGE TC 212 2013) and the interaction between structural and geotechnical engineering. For numerical analysis based on the finite element method, guidance is given on creating the model and performing the calculations before providing basic information on the requirements for the site investigation, supervision of the construction process and monitoring of the foundation performance. Detailed case studies illustrate the design and performance of CPRFs, and a design example for the foundation of a multi-storey office building founded in non-cohesive soil is investigated, carrying out 3D finite element analysis to estimate deformations and design parameters for structural engineering. Based on the combined experience of the authors obtained in the last decades working in the industry and research, the book particularly suits consulting engineers engaged in foundation engineering, as well as graduate students and researchers interested in the bearing behaviour of piled rafts and pile groups.