A geotechnical perspective on soil-termite interaction: Role of termites in unsaturated soil properties

The soil-insect interaction has gathered significant attention in the recent years due to its contribution to bio-cementation. Termites, as a group of cellulose-eating insects, alter physical (texture) and chemical (chemical composition) properties of soil. Conversely, physico-chemical properties of soil also influence termite activities. It is vital to understand the soil-termite interaction and their influence on hydraulic properties and shear strength of soil, which are related to a series of geotechnical engineering problems such as ground water recharge, runoff, erosion and stability of slopes. In this study, an attempt has been made to review the latest developments and research gaps in our understanding of soil-termite interaction within the context of geo-environmental engineering. The hydraulic properties and shear strength of termite modified soil were discussed with respect to soil texture, density and physico-chemical composition. The incorporation of hysteresis effect of soil water characteristic curve, and spatio-temporal variations of hydraulic conductivity and shear strength of termite modified soil is proposed to be considered in geotechnical engineering design and construction. Finally, the challenges and future trends in this research area are presented. The expertise from both geotechnical engineering and entomology is needed to plan future research with an aim to promote use of termites as maintenance engineers in geotechnical infrastructure.