Centrifuge model test on behavior of grid-type improved ground subjected to Level 2 earthquake ground motion

Abstract

The secondary design of building is not mandatorily required in Japan. However, to rationally design the building and minimize the earthquake damage, it is important to consider the secondary design of not only the foundation structure, but also the interaction between the ground and the superstructure. Therefore, as the first step to understand the response of the foundation structure during L2 earthquake motion, we focused on the ground improvement for liquefaction countermeasures. In this research, in order to clarify the mechanical behavior and effect of the liquefaction mitigation subjected to L1 and L2 earthquake ground motions, centrifuge model tests using the soil-cement grid with assumed thickness, area replacement ratio and interval corresponding to the construction site were conducted. The test results show that even if the soil-cement gird is damaged such as cracks, the shear deformation of the improved ground due to subsequent earthquake motion could be partially reduced.