Dissipated energy verification on silica sand and volcanic sandy ash soil Shirasu with chemical grouting and compaction under triaxial cyclic behavior

摘要

Saturated and unsaturated shearing behavior on sand, Shirasu, which is volcanic ash sand with pumice, and improved Shirasu (cement, chemical grouted and well compacted Shirasu) were investigated to valuate earthquake proof performance by cyclic triaxial test. Referencing that cyclic mobility, cumulated dissipated energy was calculated and compared with each other. Stress history, drainage conditions and degree of saturation influenced the dissipated energy. Improved soils became tough, reduced excess pore water pressure by positive dilatancy, and required more dissipated energy to reach 2.5% of single amplitude strain. Relation between liquefaction strength and dissipated energy could be approximately classified. Generally dissipated energy could be verified the soil performance during cyclic loading.