• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.381-384
• /
• 2006

In order to evaluate the seismic performance of a reinforced concrete building structure, four different analyses are carried out. Firstly, conventional pushover analysis with code-specified inverted triangular load pattern is conducted. Secondly, the pushover analysis with uniform load pattern is performed. Thirdly, adaptive pushover analyses with spectral amplification for both EC 8 artificial and Northridge earthquake are carried out. Lastly, incremental dynamic analyses under a number of scaled PGA for both EC 8 artificial and Northridge earthquake record are performed. Comparative studies demonstrate that the adaptive pushover analysis may be able to explain the response characteristics that conventional pushover analysis with fixed load distribution fails to capture.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.608-612
• /
• 2003

In the seismic response analysis, the artificial earthquake time history is generated to do the exact seismic analysis for the complex structural system like as containment building. In the present study the several simulated earthquakes are generated by use of SIMQKE program and the time history dynamic analysis of containment building is performed. Also, the seismic responses are statistically analyzed. The seismic response uncertainty arisen from the simulation of earthquakes is one of major uncertainties and the statistical description is needed to account for the random nature of earthquake.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
• /
• pp.28-35
• /
• 2001

Liquefaction potential on the specific site of nuclear power plant is analyzed and reviewed. The layered site fur this study consists of silt and sand. Based on the limited available soil data, maximum shear strength at critical locations using Seed & Idriss method and computer program SHAKE is calculated, and liquefaction potential is reviewed. Seismic input motion used fur the assessment of liquefaction is the artificial time history compatible with the US NRC regulatory Guider .60. Assessment results of the liquefaction are validated by analyzing to the other typical soil fecundations which can show the effects of foundation depth and soil data.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2005년도 학술발표회 논문집
• /
• pp.62-67
• /
• 2005

A new picking algorithm has been developed on real-time basis for finding the onset of P wave as well as discriminating the micro seismic signal from artificial noise. Unlike the previous methods which have used the STA/LTA ratio for discriminating the P arrivals, we have adopted the slope discrimination methods for identifying the P onset. As result, this algorithm has been turned out to be efficient in both accuracy and computation in on-line system.

• Structural Engineering and Mechanics
• /
• 제75권3호
• /
• pp.295-309
• /
• 2020

The construction of Reinforced Concrete (R/C) buildings with unreinforced masonry infills is part of the traditional building practice in many countries with regions of high seismicity throughout the world. When these buildings are subjected to seismic motions the presence of masonry infills and especially their configuration can highly influence the seismic damage state. The capability to avoid configurations of masonry infills prone to seismic damage at the stage of initial architectural concept would be significantly definitive in the context of Performance-Based Earthquake Engineering. Along these lines, the present paper investigates the potential of instant prediction of the damage response of R/C buildings with various configurations of masonry infills utilizing Artificial Neural Networks (ANNs). To this end, Multilayer Feedforward Perceptron networks are utilized and the problem is formulated as pattern recognition problem. The ANNs' training data-set is created by means of Nonlinear Time History Analyses of 5 R/C buildings with a large number of different masonry infills' distributions, which are subjected to 65 earthquakes. The structural damage is expressed in terms of the Maximum Interstorey Drift Ratio. The most significant conclusion which is extracted is that the ANNs can reliably estimate the influence of masonry infills' configurations on the seismic damage level of R/C buildings incorporating their optimum design.

• 한국공간구조학회논문집
• /
• 제8권6호
• /
• pp.59-66
• /
• 2008

대부분의 대공간구조물은 극장, 스타디움, 체육관 등 공공성을 가지게 되어 내진안전성에 있어서 중요성이 많이 인식되고 있다. 그러나 구조형식 및 형상에 관하여 다양성을 가지고 있는 대공간구조물이 동적하중인 지진하중을 받을 때 나타나는 구조물의 거동은 파악하기 힘들다. 본 논문에서는 대공간구조의 주 구조요소인 아치구조물에 대하여 고유진동모드를 검토하였고 모의지진파를 입력하여 지진거동특성을 분석한 결과로서 아치구조물은 설계가속도스펙트럼의 크기보다 장주기 성분에 더 많은 영향을 받는다는 것을 파악하였다.

• Earthquakes and Structures
• /
• 제15권4호
• /
• pp.431-441
• /
• 2018

This study provides fragility-based assessment of seismic performance of reinforced concrete bridges. Seismic fragility curves were created using nonlinear analysis (NA) and artificial neural networks (ANNs). Nonlinear response history analyses were performed, in order to calculate the seismic performances of the bridges. To this end, 306 bridge-earthquake cases were considered. A multi-layered perceptron (MLP) neural network was implemented to predict the seismic performances of the selected bridges. The MLP neural networks considered herein consist of an input layer with four input vectors; two hidden layers and an output vector. In order to train ANNs, 70% of the numerical results were selected, and the remained 30% were employed for testing the reliability and validation of ANNs. Several structures of MLP neural networks were examined in order to obtain suitable neural networks. After achieving the most proper structure of neural network, it was used for generating new data. A total number of 600 new bridge-earthquake cases were generated based on neural simulation. Finally, probabilistic seismic safety analyses were conducted. Herein, fragility curves were developed using numerical results, neural predictions and the combination of numerical and neural data. Results of this study revealed that ANNs are suitable tools for predicting seismic performances of RC bridges. It was also shown that yield stresses of the reinforcements is one of the important sources of uncertainty in fragility analysis of RC bridges.

• 한국공간구조학회논문집
• /
• 제18권4호
• /
• pp.97-104
• /
• 2018

A connected control method for the adjacent buildings has been studied to reduce dynamic responses. In these studies, seismic loads were generally used as an excitation. Recently, multi-hazards loads including earthquake and strong wind loads are employed to investigate control performance of various control systems. Accordingly, strong wind load as well as earthquake load was adopted to evaluate control performance of adaptive smart coupling control system against multi-hazard. To this end, an artificial seismic load in the region of strong seismicity and an artificial wind load in the region of strong winds were generated for control performance evaluation of the coupling control system. Artificial seismic and wind excitations were made by SIMQKE and Kaimal spectrum based on ASCE 7-10. As example buildings, two 20-story and 12-story adjacent buildings were used. An MR (magnetorheological) damper was used as an adaptive smart control device to connect adjacent two buildings. In oder to present nonlinear dynamic behavior of MR damper, Bouc-Wen model was employed in this study. After parametric studies on MR damper capacity, optimal command voltages for MR damper on each seismic and wind loads were investigated. Based on numerical analyses, it was shown that the adaptive smart coupling control system proposed in this study can provide very good control performance for Multi-hazards.

• Smart Structures and Systems
• /
• 제32권1호
• /
• pp.49-59
• /
• 2023

A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

• 한국지진공학회논문집
• /
• 제2권4호
• /
• pp.1-10
• /
• 1998

지진규모, 진앙거리, 지반조건 및 가옥의 노후도를 고려하여 역사지진의 규모를 추정하였다. 진진규모 6-8, 진앙거리 5 km-350km, 단단한 지반 및 연약 지반 특성을 갖는 18개의 인공지진파를 작성하여 우리 나라 전통 초가삼간에 대한 비선형 동적해석을 수행하였다. 가옥의 경년에 따른 노후도는 목조 프레임의 수평내력에 관한 이력특성이 선형적으로 감소하는 것으로가정하였다. 초가삼간을 1질점계의 1자유도 모델로 모델링하였으며, 비선형 이력특성은 개량형 Double-Targe모델을 이용하였다. 해석결과 원거리 지진에 대해서는 지진규모, 지반조건 및 노후도에 상관없이 매우 적은 피해를 보였다. 중거리 지진의 경우 연약지반에서 규모 6.5 이상의 지진시 반파 이상의 피해가 발생하였다. 근거리 지진의 경우 지반조건 및 노후도에 상관없이 규모 6.5 이상에서 반파 이상의 피해를 나타내었다. 우리 나라 역사지진의 규모는 약 6.2로 추정된다. 우리 나라에 적합한 지반가속도-진도의 경험식을 제안하였다.