This study evaluates the potentials of liquefaction caused by the 2017 moment magnitude 5.4 earthquake in Pohang City, South Korea. We obtain shear wave velocity profiles measured by suspension PS logging tests at the five sites near the epicenter. We also perform downhole tests at three of the five sites. Among the five sites, the surface manifestations (i.e., sand boils) were observed at the three sites, and not at the other two sites. The maximum accelerations on the ground surface at the five sites are estimated using the Next Generation Attenuation relationships for Western United State ground motion prediction equations. The shear wave velocity profiles from the two tests are slightly different, resulting in varying cyclic resistance ratios, factors of safety against liquefaction, and liquefaction potential indices. Nevertheless, we found that both test approaches can be used to evaluate liquefaction potentials. The liquefaction potential indices at the liquefied sites are approximately 1.5–13.9, whereas those at the non-liquefied sites are approximately 0–0.3.

这项研究评估了由韩国浦项市2017年5.4级地震引起的液化潜力。我们获得了在震中附近的五个地点通过悬浮PS测井测试测得的横波速度剖面。我们还在五个站点中的三个站点执行井下测试。在这五个位置中，在三个位置而不是其他两个位置观察到了表面表现（即沙沸）。使用美国西部地震动预测方程的下一代衰减关系来估算五个地点在地面上的最大加速度。两次测试的剪切波速度曲线略有不同，导致循环电阻比，液化安全性因素和液化电位指数的变化。不过，我们发现，两种测试方法均可用于评估液化潜力。液化位点的液化势指数约为1.5-13.9，而非液化位点的液化势指数约为0-0.3。