Abstract:  The original site of a large storage tank project was formed by hydraulic filling. The shallow hydraulic fill sand was severely liquefied, and the lower layer was a soft soil layer of underconsolidated muddy clay. The entire site needed to be pretreated to reduce or eliminate liquefaction and underconsolidated soil. According to the characteristics of the soil layer, the foundation of the project site was treated using drainage consolidation method. Drainage boards were inserted into the site first. Taking into account the factors of construction period and cost, different areas were treated with dynamic compaction, preloading, and vibration sand compaction pile schemes, respectively. The pre-treatment of the site effectively reduced the adverse effects of liquefaction and underconsolidated soil. Based on the pre-treatment effect of the site and the detailed survey, this project can adopt the scheme of drilled cast-in-place pile or prefabricated pile. The pile type was optimized based on the test pile situation, and the use of pipe pile greatly saved the investment and the construction period.

Key words: drainage consolidation, preloading; dynamic compaction, vibration sand compaction pile, pipe pile