Effect of jet grouting columns to mitigate seismic effects in sandy soil under raft foundation.

This paper investigated the seismic behavior of a laboratory model for a raft foundation of a seven-story building resting on loose fine sandy soil before and after improvement using the cement grouting technique as liquefaction and settlement countermeasures. A shaking table device with a single degree of freedom using three earthquake time histories is utilized for simulating earthquake effects. The soil improvement was implemented by jet grouting columns (using ordinary Portland cement with a W/C ratio equal to unity) injected by a locally manufactured laboratory setup. The results of improved soil by the cement grouting technique have sustainable and geotechnical beneficial effects on the seismic response of the system during earthquake loads. [ABSTRACT FROM AUTHOR]