ABSTRACT
Liquefaction remains a major geotechnical hazard in seismically active zones. Traditional mitigation methods while effective, frequently have significant environmental and economic impacts and may not be suitable for existing structures. Biogeotechnical methods, notably Microbially Induced Calcite Precipitation (MICP), offer a sustainable alternative. Experiments reveal that MICP enhances liquefaction resistance, even at low calcite contents. However, the lack of models capturing this behavior hinders the design and adoption of these techniques. This study presents Hujeux-BC, a mechanical constitutive model for the cyclic behavior of biocemented soils. It independently incorporates the main characteristics of biocementation, densification and interparticle bonding. This is done by modifying the materials elastic parameters and relative density, as well as the addition of a bonding parameter. Using the measured calcite content and change in shear wave velocity, the model is able to simulate the cyclic behavior of biocemented soils. Notably, in an undrained cyclic direct simple shear (DSS) test, the model can simulate the porewater pressure generation, accurately estimating the number of cycles needed to trigger liquefaction. This accuracy and the model’s straightforward calibration process provide a powerful tool for designing and optimizing MICP-based mitigation techniques, leading to more targeted and sustainable solutions.
