Liquefaction Mitigation of Silty Sands via Microbial Induced Partial Saturation: Fid-Bau Portal

Liquefaction Mitigation of Silty Sands via Microbial Induced Partial Saturation

Mousavi, Sayedmasoud / Ghayoomi, Majid

Both field and laboratory studies have shown that loose saturated sands containing nonplastic fines are highly susceptible to liquefaction. However, current liquefaction countermeasures for these soils are restricted due to their low permeability, environmental effects, and high costs. Microbial induced partial saturation (MIPS) via denitrification is a new emerging soil improvement technique that utilizes biochemical activities to generate biogenic gas and increase the liquefaction resistance of fully saturated soils. MIPS can offer a promising, quick, sustainable, and cost-effective method to effectively improve liquefaction resistance of silty sands. In this study, a direct simple shear (DSS) apparatus was used to experimentally investigate the response of induced partially saturated silty sands to cyclic loads. Water pressure sensor and (LVDT) were used to monitor excess pore water generation and deformation of treated specimens under strain-controlled cyclic tests. Results revealed that MIPS treated samples had significantly higher liquefaction resistance compared to untreated samples. Both generation of excess pore pressure and vertical deformation were considerably reduced as the degree of saturation decreased. From this study, it can be concluded that MIPS may potentially introduce a more effective technique than other techniques such as grouting and microbial induced carbonate precipitation where the permeability of soil limits the effectiveness.