earticle

영어

Due to the earthquake in Türkiye, the importance of preventing earthquake damage has increased worldwide. Korea is not safe from earthquakes, either. In 2016 and 2017, a Gyeongju earthquake with a record-high magnitude (ML 5.8) and the Pohang earthquake (ML 5.4) occurred. In addition, in Korea, earthquakes with a magnitude of 3.0 or higher have occurred about 12 times a year on average in the last 10 years (2013-2022), so it is necessary to prepare for damage prevention. The objective of this study is to explain the measures to prevent landslides caused by earthquakes in Korea. Since there are no cases of earthquake-induced landslides in Korea, the evaluation factors were derived by analyzing overseas studies. In addition, the applicability of the landslide hazard map on the national scale of Korea was examined. The earthquake-induced landslide hazard map was also established on a pilot basis based on the fault zone and epicenter of Pohang using seismic attenuation. Finally, an experimental study was conducted for critical rainfall adjustment for early warning after the earthquake. Three soil samples were collected from the cut-slope area in mountains and a direct shear test was performed to calculate the strength parameters according to the change in the water content ratio. In addition, the ring shear test according to the change in the water content ratio and the change in shear strength due to water supply during the shear was analyzed. Since Korea's landslide hazard map reflects topography, geology, and forest floor conditions, it has been shown that it is reasonable to evaluate the risk of earthquake-induced landslides using it. As a result of evaluating the risk of landslides based on the fault zone and epicenter in the Pohang area, the risk grade was changed to reflect the impact of the earthquake. As a result of the direct shear test, the cohesion decreased linearly as it approached the saturation state. When water was supplied during the ring shear test, the maximum shear strength decreased by 65.7-74.8% and the residual shear strength decreased by 53.5-60%. The risk map based on the fault zone is effective when used in the selection of a target site for preventive erosion control work to prevent damage from earthquake-induced landslides. In addition, the risk map based on the epicenter can be used for efficient follow-up management in order to prioritize damage prevention measures, such as to investigate the current status of landslide damage after an earthquake, or to restore the damaged area. Also, it is more likely that landslides will occur due to rainfall after the earthquake.