Liquefaction Mitigation Analysis Using Vertical Drain

Abstract

Liquefaction in semi-permeable soils such as fine sands occurs when the required time to transfer the pore water pressure into the form of effective stress is longer than the increased time of pore water pressure. Therefore, liquefaction mitigation needs to be done to speed up the air pressure flow time during an earthquake such as using vertical drains in this study. The data used here are adopted from previous studies that have been taken from a field test in Air Tawar, Padang. The results showed there is liquefaction potential based on soil data processing. The equivalent circle diameter value for the vertical drain is 1.2 m or a radial equivalent value of 0.6 m. Based on the analysis, the 60% pore water pressure dissipation within 20 seconds was obtained at a distance of 0.291 m in the radial direction. From the data above, it can be obtained that the vertical drain is capable of dissipating 60% of water pressure within 20 seconds to avoid liquefaction within the soil mass. Then it can be concluded that the application of vertical drain at a certain distance and depth can mitigate liquefaction in soil layers.