Comparison of Liquefaction Damage Reduction Performance of Sheet Pile and Grouting Method Applicable to Existing Structures Using 1-G Shaking Table

Abstract

This study conducted 1-G shaking table tests to compare methods of reducing liquefaction damage during earthquakes. The sheet pile and grouting methods were selected as applicable to existing structures. Model structures were manufactured for two-story buildings. A sine wave with an acceleration of 0.6 g and a frequency of 10 Hz was applied to the input wave. Certain experiments determined the effect of various sheet pile embedded depth ratios and grouting cement mixing ratios on reducing structural damage. The results confirmed that when the sheet pile embedded depth ratio was 0.75, the structure’s settlement decreased by approximately 79% compared to the control model. When the grouting cement mixing ratio was 0.45, the structure’s settlement decreased by approximately 85% compared to the untreated ground. In addition, the sheet pile method suppressed the increase in pore water pressure compared to the grouting method but tended to interfere with the dissipation of pore water pressure after liquefaction occurred. Additionally, comparing the effect of each method on reducing liquefaction damage revealed that the grouting method resulted in less settlement, rotation of the structure, and pore-water-pressure dissipation than the sheet pile method. Overall, the grouting method is more effective in reducing liquefaction damage than the sheet pile method. This study forms a basis for developing a liquefaction-damage reduction method applicable to existing structures in the future.