Sustainable Design for Unpiled-Raft Foundation Structure

This abstract forms Part 1 of 4 of full report on research work: “Bearing and settlement behaviour of piled-raft in soft clay.” The convention approach on piled-raft design tends to ignore load bearing and settlement contribution from the raft slab. Thus, selecting an effective raft size taking into effect of the soil-structure interaction environment is often neglected and this resulted with conservative design, expensive piled-raft foundation structure, depleting of resources and ineffective construction – in all, expensive and non-sustainable work This report evaluates on the conventional design approach, problems and limitations faced and propose possible alternative design approach to derive an optimum raft size which are both effective and practical based on the load bearing and settlement criteria. The model would then be used on piled-raft foundation in the next phase of research work to study any significance contribution from the raft and it level of contribution through similar parametrics. Analyses work and charts done would be used to support the selection of the most efficiency raft size model through the use of FEM geotechnical software in both short and long terms design consideration with structure founded on homogeneous normal consolidated soft clay overlaying a thickness of firm clay soil strata. As such, all presentations in this paper would only be encompassing solely on unpiled-raft foundation design under undrained condition since clay soil is expected to consolidate with times and gets firmer and stronger in long term. A sustainable design chart together with self-explained flowchart to serve as quick-reference design guide is developed for completeness.