External GFRP confinement to decrease near-fault earthquake damage of reinforced concrete structures considering soil-structure interaction

Abstract

In this study, low and medium-rise non-ductile RC frame structures were selected and strengthened by external GFRP confinement. Non-linear time-history analyses, followed by damage analyses, were carried out for the un-strengthened and strengthened frames under different near/far-fault earthquakes, without and with soil-structure interaction (SSI). The obtained results indicated that the external GFRP confinement successfully prevents the collapse of non-ductile RC frames located in near-fault areas in 2 km proximity to the fault. In 5–10 km proximity to the fault, GFRP confinement reduces the damage from severe damage to moderate damage or from moderate damage to light damage. The results also reaffirm that external GFRP confinement can be effective to fix design errors. With raft foundation on stiff soil, the SSI effect on near-fault earthquake damage of the frames can be negligible. These conclusions can be helpful for mitigating the seismic risk of 1970s-code-compliance or design-error structures.