Liquefaction Mitigation of Silty Sands with MICP

Liquefiable soils require remediation to reduce the consequences of liquefaction. Methods used for improving sands can become restricted when applied to silty sands. These restrictions include lower permeability, environmental impacts, and higher costs. Therefore investigating the application of a new and more natural soil improvement method which can overcome these restrictions is necessary. Microbial induced calcium carbonate precipitation (MICP) is a natural and sustainable soil improvement method which increases the soil's strength and stiffness. In this project, MICP is applied to study the changes in the undrained monotonic and cyclic shear response of silty sands with varying levels of fines content (0 to 35%). Dry pluviation method was applied to prepare the soil specimens using mixtures of Nevada sand and silica flour. The untreated specimens were consolidated under the effective stress of 50 kPa and then sheared. The MICP treated specimens were first consolidated under 15 kPa of effective stress and treatment was performed to achieve a shear wave velocity of about 400 m/s. Once treatment was finished, the specimens were consolidated under 50 kPa of effective stress. All specimens were sheared with a rate of 50% strain per hour. The calcium carbonate content of MICP treated specimens were measured using acid washing. The data herein presents the reduced data and information such as specimen height, cross sectional area, mass of soil, void ratio, calcium carbonate content, shear wave velocity, consolidation volume change, strain rate, cyclic stress ratio (CSR) and number of cycles to liquefaction (N). The datasets can be used by researchers who study the experimental and numerical liquefaction response of untreated and MICP treated silty sands.