• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.300-307
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• 1999

신경망기법을 이용한 구조물접합부의 손상평가기법을 제안하였다. 신경망기법의 성능을 개선하기 위하여 노이즈첨가학습을 수행하였으며 효과적인 손상평가를 위하여 부분구조추정법 및 data perturbation scheme을 도입하였다. 10층 프레임구조물에 대한 수치해석과 2층 프레임구조물에 대한 실험연구를 통하여 제안기법을 검증하였다 계측지점이 부분구조로 제한되고 계측자료가 노이즈를 포함하는 경우에는 제안기법이 효과적으로 적용될수 있음을 알 수 있었으며 실험을 통하여 실제 구조물에 대한 제안기법의 적용성을 평가힐 수 있었다.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.43-50
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• 2009

Strong ground motion attenuation relationship represents a comprehensive trend of ground shakings at sites with distances from the source, geology, local soil conditions, and others. It is necessary to develop an attenuation relationship with careful considerations of characteristics of the target area for reliable seismic hazard/risk assessments. In the study, observed ground motions from the January 2007 magnitude 4.9 Odaesan earthquake and the events occurring in the Gyeongsang provinces are compared with the previously proposed ground attenuation relationships in the Korean Peninsula to select most appropriate one. In the meantime, a few strong ground motion attenuation relationships are proposed and introduced in HAZUS, which have been designed for the Western United States and the Central and Eastern United States. The selected relationship from the ones for the Korean Peninsula has been compared with attenuation relationships available in HAZUS. Then, the attenuation relation for the Western United States proposed by Sadigh et al. (1997) for the Site Class B has been selected for this study. Reliability of the assessment will be improved by using an appropriate attenuation relation. It has been used for the earthquake loss estimation of the Gyeongju area located in southeast Korea using the deterministic method in HAZUS with a scenario earthquake (M=6.7). Our preliminary estimates show 15.6% damage of houses, shelter needs for about three thousands residents, and 75 life losses in the study area for the scenario events occurring at 2 A.M. Approximately 96% of hospitals will be in normal operation in 24 hours from the proposed event. Losses related to houses will be more than 114 million US dollars. Application of the improved methodology for loss estimation in Korea will help decision makers for planning disaster responses and hazard mitigation.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.4
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• pp.89-95
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• 2003

In this paper, an algorithm to locate and size damage in a complex truss structure using the time domain response is presented. Sampled response data for specific time interval is spatially expanded over the structure to obtain the mean train energy for each element of the structure. The mean strain energy for each element is, in turn, used to build a damage index that represents the ratio of the stiffness parameter of the pre-damaged to the post-damaged structure. The validity of the methodology is demonstrated using data from a numerical example of a space truss structure with simulated damage. Also in the example, the effects of noisy data on the proposed algorithm are examined by adding random noised to the response data.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.33-44
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• 2004

This paper is focused on the spatial variability of measured strong motion data during earthquake and its relationship with the performance of water distribution pipelines and residential buildings. Analyses of strong motion and the correlations of peak ground velocity (PGV) and pipeline and building damage were conducted with a very large geographical information system (GIS) database including the relationship of time and earthquake intensity and the measured location, and Kriging spatial statistics. Kriging was used to develop regressions of pipeline repair rate (RR) and residential building damage ratio (DR) associated with $90\%$ confidence peak ground velocity (PGV). Such regressions using Kriging provide an explicit means of characterizing the uncertainty embodied in the strong motion data compared with other spacial statistics such as inverse distance method.

• Journal of Digital Contents Society
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• v.19 no.5
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• pp.899-906
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• 2018

In the entire process of disaster management, it is very significant to construct related information as well as perform quantitative assessment of damage losses with respect to minimizing the effect of disasters. Many countries have paid much attention not only to studying risk assessment methodologies including constructing inventories, hazard mapping, vulnerability assessment and direct/indirect damage loss estimation, but also to developing risk analysis tools investigated in this paper. We conducted comparison studies of representative earthquake damage risk analysis tools, and the result of this study is able to provide useful information to decision makers and researchers who can contribute to development of effective disaster management.

• Advances in Computational Design
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• v.8 no.2
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• pp.97-112
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• 2023

The Finite Element (FE) modeling of Reinforced Concrete (RC) under seismic loading has a sensitive impact in terms of getting good contribution compared to experimental results. Several idealized model types for simulating the nonlinear response have been developed based on the plasticity distribution alone the model. The Continuum Models are the most used category of modeling, to understand the seismic behavior of structural elements in terms of their components, cracking patterns, hysteretic response, and failure mechanisms. However, the material modeling, contact and nonlinear analysis strategy are highly complex due to the joint operation of concrete and steel. This paper presents a numerical simulation of a chosen RC column under monotonic and cyclic loading using the FE Abaqus, to assessthe hysteretic response and failure mechanisms in the RC columns, where the perfect bonding option is used for the contact between concrete and steel. While results of the numerical study under cyclic loading compared to experimental tests might be unsuccessful due to the lack of bond-slip modeling. The monotonic loading shows a good estimation of the envelope response and deformation components. In addition, this work further demonstrates the advantage and efficiency of the damage distributions since the obtained damage distributions fit the expected results.

• Earthquakes and Structures
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• v.17 no.6
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• pp.599-609
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• 2019

After an earthquake, a quick seismic assessment of a structure can facilitate the recovery of operations, and consequently, improve structural resilience. Especially for facilities that play a key role in rescue or refuge efforts (e.g., hospitals and power facilities), or even economically important facilities (e.g., high-tech factories and financial centers), immediately resuming operations after disruptions resulting from an earthquake is critical. Therefore, this study proposes a prompt post-earthquake seismic evaluation method that uses displacement and acceleration measurements taken from real structural responses that resulted during an earthquake. With a prepared pre-earthquake capacity curve of a structure, the residual seismic capacity can be estimated using the residual roof drift ratio and stiffness. The proposed method was verified using a 6-story steel frame structure on a shaking table. The structure was damaged during a moderate earthquake, after which it collapsed completely during a severe earthquake. According to the experimental results, a reasonable estimation of the residual seismic capacity of structures can be performed using the proposed post-earthquake seismic evaluation method.

• Journal of the Korean Geotechnical Society
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• v.28 no.5
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• pp.55-65
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• 2012

The purpose of this study is to estimate seismic damage for harbor site considering dynamic amplification characteristics. First of all, a series of ground response analysis is performed and then correlation equations between rock outcrop accelerations and peak ground accelerations (PGAs) are determined. These equations are saved into DB and when an earthquake occurs, PGAs are determined by them as soon as possible. For earthquake events, seismic damage grades of harbor structures are determined by using the correlated PGAs and fragility curves of harbor structures in real time. In this study, seismic damage was estimated and classified into several grades by applying two hypothetical earthquakes.

• Computers and Concrete
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• v.15 no.6
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• pp.921-933
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• 2015

The aim of this study is to determine the earthquake performances of reinforced concrete (R/C) residential buildings in Turkey and to analyze the parameters that affect the performance. The performance of Turkish residential buildings, determined by their levels of damage, directly relates to their structural systems. Damage parameters observed from previous earthquakes define structural parameters selected to be used in the present study. Five different types of frame R/C buildings were modeled. For the analysis, the model buildings vary according to the number of stories, column sizes, and reinforcement and concrete strength parameters. The analyses consider gravity forces and earthquake loads through 1975 and 2007 Turkish design codes. In a total of 720 different R/C buildings were investigated for the analysis to obtain capacity curves. A performance evaluation was employed by considering the Turkish design code (TDC-2007). The current study ignores irregularities such as soft stories or short columns. The study's analysis considers a comparison of the parameters' influence on the structural performance of the model buildings.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.154-163
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• 2018

Not only South Korea but also Global world show that the frequency and damages of large-scale natural disaster due to the rise of heavy rain event and typhoon or hurricane intensity are increasing. Natural disasters such as typhoon, flood, heavy rain, strong wind, wind wave, tidal wave, tide, heavy snow, drought, earthquake, yellow dust and so on, are difficult to estimate the scale of damage and spot. Also, there are many difficulties to take action because natural disasters don't appear precursor phenomena However, if scale of damage can be estimated, damages would be mitigated through the initial damage action. In the present study, therefore, wind wave damage estimation functions for the western coastal zone are developed based on annual disaster reports which were published by the Ministry of Public Safety and Security. The wind wave damage estimation functions were distinguished by regional groups and facilities and NRMSE (Normalized Root Mean Square Error) was analyzed from 1.94% to 26.07%. The damage could be mitigated if scale of damage can be estimated through developed functions and the proper response is taken.