MITIGATION OF EARTHQUAKE INDUCED LIQUEFACTION HAZARDS, A CASE STUDY: BANDAR ABBAS DRY DOCK PROJECT

The effectiveness of the dynamic compaction method as a mitigation measure against the risk of liquefaction has been assessed in a case study involving the foundation of two 300,000 ton dry docks located in port of Bandar Abbas in Iran. Subsurface investigations revealed that there is a high liquefaction potential in a layer beneath the major industrial facilities. A comprehensive Probabilistic Seismic Hazard Assessment (PSHA) has been performed to evaluate the local Peak Ground Acceleration (PGA) based on various risk levels. Site investigation and liquefaction assessment confirmed that ground improvement was required as part of the hazards mitigation. Among several techniques, dynamic compaction method has been selected based on considerations of ground conditions, operational impacts, degree of improvement required, and environmental aspects. Liquefaction susceptibility and the efficiency of dynamic compaction method have been evaluated by in-situ Standard Penetration Test (SPT) data obtained before and after the compaction. The results demonstrate that dynamic compaction as a liquefaction remedial measure decreases the liquefaction potential to an acceptable level and so its efficiency was approved.