The Potential Use of Biopolymers as a Sustainable Alternative for Liquefaction Mitigation

The Potential Use of Biopolymers as a Sustainable Alternative for Liquefaction Mitigation—A Review

Smitha, S. / Rangaswamy, K.

Saturated cohesionless soils, when subjected to sudden loads like earthquake, will exhibit a phenomenon called liquefaction and start behaving like a liquid. This is due to the sudden build-up of excess pore water pressure that results in the complete loss of shear strength. Most of the traditional liquefaction mitigation approaches have several limitations like high cost and labour, disturbance to existing structures and other environmental issues. This paper reviews a series of researches that involve contemporary liquefaction mitigation practices and their mechanisms. It also presents a concise review of the application of bio-geotechnical methods for soil improvement, focusing on the use of biopolymers. Biopolymers are of biological origin and are environmentally friendly. They consist of repeating monomeric units bonded together to form a long polymeric chain and they are used commonly in the chemical as well as the food industry. In the past decade, numerous researches have been carried out to demonstrate their use in the field of geotechnical engineering to improve the various properties of soil. Biopolymers like xanthan, agar, guar, chitosan and starch were found to improve soil properties such as shear strength, permeability and compressibility significantly. Thus, biopolymers could be used to create engineered soil with modified properties in this epoch of depleting natural resources. Findings from the review of works of the literature indicate the prospective use of biopolymers as a sustainable substitute for preventing soil failure due to liquefaction in view of their pore filling and shear strength enhancement properties. Furthermore, the need for exhaustive research on the proposed concept is suggested.