What methods are used for liquefaction mitigation and how are they designed?

Liquefaction mitigation methods: (1) Densification - vibrocompaction (free-draining soils), dynamic compaction (shallow deposits), compaction grouting - target relative density >70%, (2) Drainage - stone columns, prefabricated drains to dissipate excess pore pressure, (3) Reinforcement - soil mixing, jet grouting to create grid of stiff elements, (4) Replacement - excavate and replace with non-liquefiable material, (5) Deep foundations - transfer loads below liquefiable layer. Design requires post-improvement verification using SPT/CPT and calculation of improved CRR values.