Remediation of structure-soil-structure interaction on liquefiable soil using densification

Earthquake induced soil liquefaction has drawn significant attention in urban areas where buildings are closely spaced due to the extensive damage it has caused on buildings in recent earthquakes. This study investigated the effect of targeted soil densification as a remediation method on one of a pair of adjacent buildings with different storey levels on liquefiable soil using dynamic centrifuge modelling. The effects of remediation on structural and foundation performance of both treated and untreated buildings are presented. It was demonstrated that localised soil densification can be effective and beneficial in treating detrimental foundation behaviours of the treated building on the liquefiable soil and an untreated adjacent building can also be beneficially affected. From a structural perspective, soil densification can reduce the structural demand on the treated building with negligible detrimental effect or even some beneficial effect on the untreated building on the liquefiable soil. In the case studied, localised soil densification when building new structures adjacent to existing ones can be an effective remediation method in improving seismic performance on liquefied soil. This study also suggests that the decision of remediating any building in an urban setting should be made after considering effects of SSSI.