• Journal of Korean Society of Steel Construction
• /
• v.18 no.5
• /
• pp.585-596
• /
• 2006

This study focuses on the seismic behavior of 3-, 9-, and 20-story steel moment resisting frame (MRF) structures designed in accordance with the 2000 International Building Code using different Response Modification factors (R factors), i.e., 8, 9, 10, 11, and 12. For a detailed case study, 30 different structures were evaluated for 20 ground motions representing the hazard level, which is equal to a 2% probability in 50 years (2% in 50 years). The results showed that the current R factors provide conservative designs for the 3- and 9-story buildings for the Collapse Prevention performance objective. the 20-story buildings, which were designed without using the minimum requirement of spectral acceleration CS prescribed in IBC 2000, did not satisfy the seismic performance for Collapse Prevention performance.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.14 no.6
• /
• pp.75-84
• /
• 2010

In current seismic design provisions, a reduced beam section with bolted web (RBS-B) connections is only permitted for intermediate moment frames (IMF). This study evaluated the seismic performance of steel moment resisting frame systems having RBS-B connections designed according to current seismic design provisions. For this purpose, 12 archetypal IMF systems having two different span lengths (9m, 6m) were designed considering two design load levels (SDC $C_{max}$, SDC $C_{min}$). A nonlinear analytical model that can simulate hysteretic behavior of an RBS-B connection was also developed in this study. The procedures specified in ATC 63 are used to conduct a seismic performance evaluation. Moreover, this study conducts the seismic performance evaluation of IMF systems designed according to a new design method proposed by the authors in the previous study. It was observed that several model frames designed according to current seismic design provisions did not provide satisfactory collapse margin ratios (ACMR). This study also showed that the model frames designed according to the new design procedures had a sufficient ACMR.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.1
• /
• pp.109-119
• /
• 2018

The purpose of this study is to analyze the geographical location information data and the damage trends according to the type of landform for the study of various cultural properties in 44 traditional places with national designated cultural properties damaged by the racing earthquake on September 12, 2016. The landform type was the most enclosed type, and the location type was more frequent in the surrounding area, such as urban and rural areas. The waterside type was located along rivers, rivers, valleys, lakes, and oceans except for the top of the mountain, but this area was found to be vulnerable to earthquakes, It is understood that it should be referred from cultural property management the side. 26 of the total 44 were temples. The elevation and slope increased with increasing of the flat type, the background type, the enclosed type, the mountain type, and the top type. Most often located on 1-20 % slopes, with the slope facing south more often than not. Within the 10 km range from the epicenter, 23% were concentrated, within the range of nearly 65 km, the background type was closest, and was concentrated in the northeast and southwest from the epicenter. In this study, it is meaningful to analyze earthquake damage in various aspects from the viewpoint of traditional space which is a landscaping cultural property and it will be used for planning, designing and managing traditional spaces.

• Journal of the Society of Disaster Information
• /
• v.14 no.4
• /
• pp.450-457
• /
• 2018

Purpose: The evaluation of seismic performance of critical structures has been emerging a key issue in Korea, since a magnitude 5.8 earthquake, the worst in Koran history, struck Gyeongju, southern area in Korea on september 12th, 2016. In particular, the catastrophic failure of nonstructural components such as sprinkler piping systems can cause significant economic loss or loss of life during and after an earthquake. The nonstructural components can be more fragile than structural components in seismic behavior. Method: This study presents the seismic performance evaluation of fire protection piping system, using coupled building-piping system installed with Triple Friction Pendulum Bearings (TPBs). Kobe (Japan), Kocaeli (Turkey), and GyeongJu (Korea) were selected to consider the uncertainty of ground motions in this study. Result: In the simulation results, it was observed that the reduction of maximum displacements of the piping system with the TPBs' system was significant: Kobe, Kocaeli, and Gyeongju cases were 49%, 14.4% and 21.5%, respectively. Conclusion: Therefore, using seismically isolated system in a building-piping system can be more effective to reduce the seismic risk than a normally installed building-piping systems without TPBs in strong earthquakes.

• Korean Journal of Remote Sensing
• /
• v.34 no.4
• /
• pp.703-708
• /
• 2018

In recent years, subsidence due to excessive groundwater withdrawal is a major problem in the Kathmandu Basin. In addition, on 25 April 2015, the basin experienced large crustal displacements caused by Mw 7.8 Gorkha earthquake. In this study, we applied StaMPS- Persistent Scatterer InSAR (StaMPS PS-InSAR) technique to estimate the spatio-temporal displacements in the basin after the mainshock. 34 Sentinel-1 C-band SAR data are used for measuring subsidence velocity during 2015-2017. We found the maximum subsidence velocity of about 9.02 cm/year and mean subsidence rate of about 8.06 cm/year in the line of sight direction, respectively, in the central part of the basin.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2016.11a
• /
• pp.240-241
• /
• 2016

본 논문에서는 지난 9월 12일에 한반도 관측 이래 최대 규모 5.8 지진이 발생한 경주 피해현황 대장(엑셀)을 지자체로부터 제공받아 피해현황에 대해 공간분석을 실시하였다. 현황정보를 기반으로 지진피해 주소 데이터를 기반으로 지오코딩을 수행하였으며 약 5,906건(95.6%)에 대한 속성정보를 공간정보화 하였다. 지질도 및 단층정보로 구축한 공간DB를 중첩 분석하여, 시각화된 지진피해 현황 결과를 제시하였다. 마지막으로 지진피해지역의 특징 및 현황 분석이 일차적으로 이루어져야 하며, 향후 지진피해 데이터 및 공간분석을 기반으로 지진 발생시 피해가 예상되는 지역에 대해 예측하는 모델링 및 시스템 고도화를 추진해야 할 것이다.

• Advances in concrete construction
• /
• v.9 no.1
• /
• pp.1-7
• /
• 2020

Retrofitting is an alteration of existing member or component of the structure. In civil engineering point of view, it is called strengthening of the old structure. Deterioration of structures may be due to aging, corrosion, failure of joints, earthquake forces, increase in service loads, etc. Such structures need urgent repair, retrofitting and strengthening to avoid collapse, cracking and loss in strength or deflection. Advanced techniques are required to be developed for the repair of structural components to replace conventional techniques. This paper focuses exclusively on torsional behaviour of Reinforced Concrete (RC) beams and retrofitted RC beams wrapped with aramid fiber. Beams were retrofitted with aramid fiber by full wrapping and in the form of 150 mm wide strips at a spacing of 100 mm, 150 mm, 200 mm respectively using epoxy resin and hardener. A total 15 numbers of RC beams of 150 mm×300 mm×1300 mm in size were cast, 3 beams are tested as control specimens, and 12 beams are tested for torsion up to the failure and then retrofitted with aramid fiber. Experimental results are validated with the help of data obtained by finite element analysis using ANSYS. The full wrapping configuration of aramid fiber regains 105% strength after retrofitting. With the increase in spacing of fabric material, torsional strength reduces to 82% with about 45% saving in material.

• Korean Journal of Remote Sensing
• /
• v.35 no.2
• /
• pp.217-228
• /
• 2019

In this study, a seismic vulnerability map of Gyeongju city, where the 9.12 Gyeongju earthquake occurred, was produced and evaluated using analytic hierarchy process(AHP) and geographic information system (GIS). Geotechnical, physical, social, structural, and capacity factors were selected as the main indicators and 18 sub-indicators to construct a spatial database. Weights derived using the AHP were applied to the 18 sub-indicators, which generated a vulnerability map of the five main indicators. After weighting the five generated maps, we created seismic vulnerability maps by overlaying each of the five maps. The seismic vulnerability map was classified into five zones, i.e., very high, high, moderate, low, and safe. For seismic vulnerability, the results indicated that 3% of Gyeongju area is characterized as having very high vulnerability, while 19% was characterized as safe. Based on district standards, Jungbu-dong, Hwangoh-dong, Hwangseong-dong, Seonggeon-dong, and Dongcheon-dong were high-risk areas, and Bodeok-dong, Gangdong-myeon, Yangbuk-myeon, Yangnam-myeon, and Oedong-eup were characterized as safe areas. The seismic vulnerability map produced in this study could possibly be used to minimize damage caused by earthquakes and could be used as a reference when establishing policies.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.5 no.4
• /
• pp.17-26
• /
• 2001

In order to estimate peak ground motions and frequency characteristics of strong ground motions in southern korea, we employed the stochastic simulation method with the moment magnitude(M$_{w}$) and the hypocentral distance(R). We estimated same input parameters that account for specific properties of source and propagation processes, and applied them to the stochastic simulation method. The stress drop($\Delta$$\sigma$) of 100-bar was estimated considering results of research in ENA, China, and southern korea. The attenuation parameter x was calculated by analyzing 57 seismograms recorded from September 1996 to October 1997 and the estimation result of the attenuation parameter x is 0.00112+0.000224 R where R is hypocenter distance. We estimated strong ground motion relations using the stochastic simulation method with suitable input parameters(e.g. $\Delta$$\sigma$, x, and so on). At last, we derived relations between hypocentral distances and ground motions(seismic attenuation equation) using results of the stochastic prediction.esults of the stochastic prediction.n.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.1 s.47
• /
• pp.33-39
• /
• 2006

Parameters including the seismic sources and the elastic wave propagation characteristics were analysed using the observed ground motions from 3 Kyoungju region earthquakes. The Levenberg-Marquardt algorithm was applied to invert all the variables non-linearly and simultaneously with S wave energy In frequency domain. Average stress drop of 3 events and local attenuation parameter ${\kappa}$ were estimated to about 48-bar and 0.0312 respectively. Regional attenuation parameter, Qo and ${\eta}$, were also estimated to be about 417 and 0.83. ${\kappa}$ values are much higher than that of EUS, even though smaller than that of WUS. All these values resultant from this study show that there are differences in some parameters of other studios due to differences in the governing equation. of acceleration motions