Mitigation of Liquefaction Potential Using Vibro Compaction-Paper

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The study evaluates vibro compaction as a method for mitigating earthquake-induced liquefaction in loose, saturated sandy soils. Liquefaction potential was assessed using cone penetration test (CPT) data and the simplified procedure in Indian Standard IS 1893:2016. The factor of safety was calculated as the ratio of cyclic resistance to earthquake-induced cyclic stress; soil is considered non-liquefiable where the factor of safety is at least 1.<br /><br />The case study concerns an industrial plant in Seismic Zone V in northeastern India. The site had sandy soils with less than 10% fines and a groundwater table approximately 1 m below ground. Initial CPT-based analysis indicated a liquefiable depth of about 11–12 m. Vibro compaction was selected to densify the soil, using a triangular treatment grid spaced 2.75 m apart. Field trials established the treatment parameters, while computerized monitoring and backfill measurements supported quality control. Approximately 10–11% of the treated soil volume was replaced with backfill to account for ground subsidence.<br /><br />Post-treatment CPT results showed cone resistance improvements of roughly 1.5–2 times. Liquefaction analyses generally produced factors of safety above 1, indicating effective mitigation. Plate load tests also confirmed improved load-settlement performance, with measured settlements within the project’s permissible limits.<br /><br />The authors conclude that vibro compaction effectively densified the site soils, reduced liquefaction risk, and met the required foundation performance criteria. The method is particularly suitable for loose sands with low fines content.

Keywords

vibro compaction

liquefaction mitigation

cone penetration test

sandy soils

factor of safety

cyclic resistance

Seismic Zone V

groundwater table

plate load test

soil densification