In taking measures to prevent damage to existing structures by liquefaction, new techniques to improve the ground immediately under an existing structure without dismantling or removing the structure are currently being sought more enthusiastically than before. As ground improvement techniques using microbial metabolism to promote the relatively slow solidification of the ground, these are expected as suitable techniques for ground improvement under existing structures.
Our research focused on the microbial carbonate precipitation (MCP), in which calcium carbonates precipitated from reactions between carbon dioxides and calcium sources by microbial metabolism binds soil particles and solidifies soil. In our research, sands solidified by MCP were subjected to cyclic triaxial tests to check their deformation characteristics. In addition, a dynamic centrifugal model test was conducted to check the effect of liquefaction countermeasure when the entire ground was solidified.