Damage of Foundation for Detached Houses in Liquefied Areas by the Tohoku Region Pacific Coast Earthquake

Abstract

Due to the Tohoku Region Pacific Coast Earthquake occurred on March 11 2011, necessity of countermeasures to liquefaction for detached houses has been increasing in Japan. In this paper, by focusing on ground condition of detached houses damaged by liquefaction, method of the conventional liquefaction judgment was verified using both the Swedish Weight Sounding test and Cone Penetration test results of 86 sites. In addition, based on 160 cases of damaged detached houses with ground reinforcement, the relationship between damage level and inclination angle of detached houses, and applied retrofitting methods was investigated. Finally, we introduced an appropriate ground reinforcement system to liquefaction and the suitable design method.