An Optimized Prefabricated Raft Footing System for Houses on Shrink-Swell Soils: Preliminary Results

The strong demand for houses has been hampered by a shortage of skilled labor in Australia, which can be potentially alleviated using prefabrication. Significant advancements in the design and construction of prefabricated houses have been observed; however, most substructure constructions still use traditional cast-in-place method that is labor intensive and weather-dependent. Prefabrication of footing systems is an advantageous solution since this require minimal manual labor and shorter construction period. The design of an innovative prefabricated footing needs to consider structural integrity and design assembly. One of the important structural issues for light-weight houses is cyclic differential ground movements affecting footing systems due to reactive soils. This shrink-swell movements are due to the decrease and increase in soil moisture, which can cause minor to severe damage depending on the presence of fines. Due to the issues on shortage of skilled labor and housing, and the costly impact of shrink-swell movements of reactive soils to footings, this study aims to develop a prefabricated footing based on optimized waffle raft. The developed system can easily be installed in stable to highly reactive sites, minimizing site disturbance, on-site assembly requirements and maximizing construction speed, quality and sustainability.