Study on improved neutral plane analysis of deep foundation for lightweight buildings on soft soil - Raft foundation on timber piles for 3-5 levels building

Sammanfattning

Current building standards and guidelines allow a timber construction to be built with more than two floors, an opening of the market to choose timber as material in load-bearing structures. Because of the weight of the building, this will lead to modification of ground foundation in consideration of low costs and less construction time. Simultaneously, this contributes to a more sustainable and climate-smart society. The objective of this thesis is to investigate ground foundations for lightweight 3-5 floors residential constructions on soft soil through variety of length of piles, placement and the number of piles and pile material, together with a new approach of calculations on pile settlements for the timber piles. The study is based on an examination of existing building of timber loadbearing construction and soil model of construction side in the middle of Gothenburg, project “The Working Lab”. One of the challenges was to investigate the interaction between piled raft and subsoil, yielding point of disturbed soil under installation of piles and down drag loads. This Master thesis evaluate the settlements and bearing capacity of the piled raft on timber piles based on the calculated assets of the presumed models. For that, the algorithm of piled raft behaviour considering optimization of the design has been created and followed. The analysis shows a positive result which fulfill Eurocode requirements. It can be used in general for timber construction and constructions with low applied loads. Further studies would be required for a development of the practical model and guidelines together with verification in practice.