Effect of Light Biocementation on the Liquefaction Triggering and Post-Triggering Behavior of Loose Sands

Microbially induced calcite precipitation (MICP) is an environmentally conscious ground-improvement method that can enhance the engineering properties of granular soils through calcium carbonate (CaCO3) on soil particle surfaces and contacts. Although numerous studies have shown ability biocementation to improve liquefaction resistance loose sands, effects light cementation levels undrained cyclic behaviors remained relatively unexplored. A series monotonic direct simple shear tests were performed examine effect (?Vs<100 m/s CaCO3 contents <0.9%) triggering post-triggering behavior Ottawa F-65 sand subjected varying loading magnitudes [cyclic stress ratio (CSR)=0.1 0.3]. Results suggest presence significantly with log-linear increases in number cycles required trigger liquefaction, which consistently correlated cementation-induced Vs increases. Despite these remarkable pretriggering improvements, almost no improvements observed strain accumulation postcyclic reconsolidation behaviors, measurements indicating small-strain largely erased following shearing events.