Byungmin Kim

This study investigates the conditions for which one‐dimensional (1‐D) nonlinear (NL) site response analysis results are distinct from equivalent‐linear (EL) results and provides guidance for predicting when differences are large enough to be of practical significance. Relative differences in spectral accelerations and Fourier amplitudes computed from NL and EL analyses are assessed for a range of site conditions and for suites of input motions appropriate for active crustal and stable continent

Downhole arrays provide enhanced understanding of dynamic soil behavior and site response. Historically, downhole array recordings have been available only for earthquakes with relatively limited durations. New recordings from a number of KiK‐net downhole arrays during the 11 March 2011, M w 9.0, subduction zone earthquake near the east coast of Honshu, Japan, allow us to investigate dynamic soil characteristics and site response due to long‐duration subduction zone earthquakes. Using these reco

A moment magnitude 5.4 earthquake struck the Pohang city located in the southeastern Korean Peninsula on 15 November 2017, possibly triggered by an enhanced geothermal system. Despite the moderate magnitude of the earthquake, extensive geotechnical and structural damage occurred. This study summarizes the widespread geotechnical damage resulted from the Pohang earthquake, observed during our reconnaissance trip. The affected area is mainly covered by Tertiary/Quaternary Alluvium underlain by mud

The time‐averaged shear ( S ) wave velocity in the upper 30 meters of sediment ( V S 30 ) is a widely used site parameter for ground motion prediction. When unavailable from measurements, as is often the case at accelerograph stations in Central and Eastern North America (CENA), V S 30 is typically estimated from proxies. We propose an alternative for CENA based on a theoretical relationship between S ‐wave velocity and the ratio of radial to vertical components of the compressional ( P )‐wave–d

Abstract An earthquake with a local magnitude (ML) of 5.4 occurred in Pohang city, South Korea, on 15 November 2017. This study focuses on the damage that affected the village of Gokgang‐ri, which is built on small‐size hills. The northern part of the village is located on the slopes facing the earthquake’s epicenter, or on plateaus behind the slopes, and serious damage (i.e., building cracks and collapses) occurred to buildings in this area. In contrast, only some buildings in the southern part

Abstract 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 a

The 2017 M5.4 Pohang, South Korea, earthquake damaged numerous buildings. Immediately after the main shock event, 1,880 professional engineers inspected the damaged buildings and assigned three damage grades (“Usable,” “Restricted use,” and “Unusable”). We investigate factors influencing the building damage. The built year, number of stories, and estimated peak ground acceleration are strongly related with the frequency of building damage. We also prove that the damage caused to the building is