Mitigation of soil liquefaction using microbial technology: An overview

Soil liquefaction is a major geo-hazard. As liquefaction could occur anywhere in a sand layer and result in large-scale lateral spreading, treatment for liquefaction needs to be carried out over a large extent. The cost-effectiveness of the treatment then becomes a major consideration. With the development of microbial geotechnologies, some new approaches for liquefaction mitigation have been developed. Some of the methods offer more advantages over the existing methods. This paper gives an overview of the recent progress in bio related soil liquefaction mitigation methods. These include both bio-cementation and biogas desaturation. The mechanisms of bio-cementation and biogas desaturation are discussed. Recent up-scaled model tests and field trials are also reviewed. The studies so far have demonstrated that there is a great potential for some of liquefaction mitigation methods to be adopted in practice, although there are still challenges that need to be studied further. These include treatment efficiency, long-term sustainability, and biosafety. A brief introduction to some emerging technologies for liquefaction mitigation such as bio-gelation and use of fungi are also introduced.