Abstract:
Australia’ s climate is defined by its extremes— frequent droughts, variable rainfall, and intense solar exposure, making it a prime candidate for solar energy generation. However, the geotechnical conditions that accompany these climatic features present unique challenges for foundation design, particularly for solar tracker systems commonly supported on shallowly driven I- or H-section piles. In regions underlain by reactive clays, ground movements associated with soil moisture fluctuations can lead to uplift forces during wet phases and reduced lateral or vertical support during dry periods. This paper reviews foundation design methods previously developed by the author for such conditions and critically examines the underlying design assumptions in light of observed ground behavior. Emphasis is placed on the impact of soil moisture state, particularly the distinction between unsaturated and partially saturated conditions, during pile installation. The findings highlight the importance of installation timing, site-specific soil and climate characterisation, and the potential consequences for long-term performance of pile-supported solar arrays.