Enhancing raft substructures of single-detached dwellings on expansive soils

Overview

The use of prefabricated systems may potentially alleviate the housing and labour shortage in most developed countries by expediting construction period, reducing material wastage and effect of weather impacts, minimising unexpected costs, skilled labour dependence and construction hazards. The full potential of prefabricated construction is yet to be realised in part due to most advancements being focused on its superstructure. The development of prefabricated substructures for lightweight buildings needs to consider the susceptibility to damage induced by the shrink-swell movement of expansive soils causing significant global financial losses. As a result, the main aim of this study is to develop practical prefabricated solutions based on raft substructures for single-detached dwellings on expansive soils using innovative approaches, such as topology optimisation, soil-structure contact finite element modelling and strut-and-tie modelling. The results of this study will help overcome most construction limitations of conventional cast-in-place monolithic raft substructure, such as faster, safer and more sustainable construction, whilst providing comparable strength and serviceability.

Key outcomes

• A developed simplified hydromechanical finite element model to simulate soil-structure interaction
• Parametric numerical simulations to determine the correlation between soil-structure movements and soil, environmental and loading factors
• An enhanced waffle pod raft using topology optimisation
• A prefabricated connection using soil-structure contact analysis and strut-and-tie model
• An application of the developed connection to a prefabricated raft substructure on expansive soils

Research team

• Bertrand Teodosio
• Prof Priyan Mendis
• Dr Kasun Shanaka Kristombu Baduge

Research partners and collaborators

• The Australian Reinforcing Company