Challenges For Solar Farm Pile Design In Reactive Soil

The procedures for the design of piles installed in clay, based on conventional soil mechanics theory, are part of the foundational knowledge of practising geotechnical engineers. Although it is common for different designers to recommend piles of varying dimensions, because of differences in their preferences for correlations and design details, the fundamental scientific approach is usually similar. Regrettably, this is not the case for the design of short piles in reactive clay, which has to rely on the continuing evolution of knowledge in unsaturated soil mechanics and contend with the scarcity of relevant publications on aspects of pile design.
This paper chronicles the on-going collaboration works involving practising geotechnical engineers from EIC Activities, a member of CIMIC Group, and academics from both The University of Sydney (USYD) and The University of NSW (UNSW) to establish some fundamental pile design input that can be agreed upon to design piles in reactive soil for solar farm projects. This paper will outline the two separate collaborations at UNSW and USYD focusing on the vertical and lateral pile design aspects, respectively, for solar farm micro piles. The collaboration at UNSW focussed on the axial design topic for a pile in reactive clay and at USYD, the collaboration dealt with the lateral design topic for a pile in unsaturated clay.