• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.424-431
• /
• 2000

After the Kobe earthquake(1995) in Japan, the Izmit earthquake(1997) in Turkey and the Chi-chi earthquake(1999) in Taiwan, the small-to-medium-sized earthquakes occurred in the Koreans peninsula and this shows the fact that Korea is not located in the safety zone of earthquake. The main concept of base isolation system is to reduce the member forces by decreasing the earthquake forces transmitted to superstructure instead of the conventional techniques of strengthening the structural members. This study investigates the effect of seismic response attenuation of computer floors using base isolation systems

• Journal of the Korean Institute of Landscape Architecture
• /
• v.32 no.5
• /
• pp.129-138
• /
• 2004

Cherishing the dead is based in sadness. Designing a memorial space therefore has an inherent challenge to evoke the feeling that is so personal and varied by providing a physical space. The tendency of memorials, especially in the US after the mid 20th century, has been to emphasis each dead individual, as seen at the Vietnam Veterans Memorial in Washington, D. C., the Oklahoma City National Memorial in Oklahoma City, and so forth. In the process of designing the memorial of the Taiwanese Chi-chi earth-quake, Cheng Kim Park Robidoux tried to set up a series of spaces through which not only the relatives of the dead but also unrelated visitors could have their own spatial experiences, private rituals and public events, so that they can finally build up a collective memory. Sky-Well consists of a large bamboo forest enclosing a void. Without a particular entrance and guiding system, visitors stroll and get lost in the bamboo forest before they find the central void. The horror they experienced during the earthquake is melted down into the motion and phenomenology of the bamboo forest whereas the central void is reinterpreted as an empty mind, where people find solace from the sky. Details, such as the bamboo wall to place commemorative flowers and lotus blossom paving, are echoing the theme of rebirth.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.04a
• /
• pp.28-35
• /
• 2000

The quality factor and the seismic source parameters such as the $\chi$ corner frequency and the stress drop were estimated from the small-to-medium instrumental earthquake data in south Korea. The Q facter with 95% confidence level ranges from 1519 to 2158. The regression equation of $\chi$in terms of epicentral distance R, is obtained as $\chi$=0.006717+0.00015R. And the stress drop is estimated as 50 bar which is similar to the previous results carried out by independent researchers. Artificial ground motions were simulated using the estimated earthquake parameter values and compared with real earthquake, The simulated response spectrum is very similar to real one.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.7 no.6
• /
• pp.59-70
• /
• 2003

We estimated the spectrum decay parameter $\chi$ and the stress parameter ($\Delta$$\sigma$) in southeastern Korea. Especially, we propose a procedure to compute site-independent $\chi$$_{q}$ and dependent $\chi$$_{s}$ values, separately, This procedure is to use the coda normalization method for the computation of site independent Q or corresponding $\chi$$_{q}$ value as the first step followed by the next step, the computation of $\chi$$_{s}$ values for each site using the given $\chi$$_{q}$ value evaluated at the first step, For the estimation of stress parameter, we used seismic data monitored from three earthquakes occurred near Gyeongju in 1999 with the method of Jo and Baag, In addition, we simulated strong ground motion using the $\chi$ value and the stress parameter, In this case, we calculated the $\chi$ value with conventional method. The $\chi$ value of 0.016+0.000157R and the stress parameter of 92-bar was applied to the stochastic simulation, At last, we derived seismic attenuation equation using results of the stochastic prediction, and compared these results with some others reported previously.ported previously.

• Journal of the Korean Society of Safety
• /
• v.27 no.1
• /
• pp.44-48
• /
• 2012

The seismic safety of long-period cable-stayed bridges is assessed by probabilistic finite element analysis and reliability analysis under NFE. The structural response of critical members of cable-stayed bridges is evaluated using the developed probabilistic analysis algorithm. In this study, the real earthquake recording(Chi-Chi Earthquake; 1997) was selected as the input NFE earthquake for investigating response characteristics. The probabilistic response and reliability index shows the different aspect comparing the result from FFE earthquake. Therefore, the probabilistic seismic safety assessment on NFE earthquakes should be performed for the exact evaluation of long-period cable-stayed bridges and the earthquake resistant design criteria should be complemented.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2003.09a
• /
• pp.82-89
• /
• 2003

Near-field ground motions exhibit special characteristics that are different from ordinary far-field ground motions. In this study the shaking table tests were conducted to evaluate the effect of earthquake ground motions with different characteristics on the response of the structure. The ground motions used in this study were the scenario earthquake, design earthquake, and Chi-Chi earthquake measured in TCU052 station. These earthquakes have different frequency contents. The test results show that the frequency content of ground motion is very important to the response of structures. The floor responses of structure were greatly affected by the higher modal frequencies, as well as the fundamental frequency. The responses of third floor were significantly reduced due to the interaction between the structure and the base isolated mass installed at the third floor.

• Structural Engineering and Mechanics
• /
• v.25 no.3
• /
• pp.291-310
• /
• 2007

Current seismic design guidelines in Japan are diverse in the seismic ground strain estimates, because the concepts on a horizontally propagating wave model are not consistent in various seismic design guidelines including gas, water and other underground structures. The purpose of this study is (a) to derive the analytical methods to estimate the ground strains for incident seismic waves, (b) to develop a statistical estimation technique of the ground strains, and finally (c) to compare the theoretical estimation with the observed data which was measured at 441 sites in the 1999 Chi-Chi Earthquake in Taiwan.

• Nuclear Engineering and Technology
• /
• v.37 no.2
• /
• pp.191-200
• /
• 2005

Shaking table tests of the seismic behavior of a steel frame structure model were performed. The purpose of these tests was to estimate the effects of a near-fault ground motion and a scenario earthquake based on a probabilistic seismic hazard analysis for nuclear power plant structures. Three representative kinds of earthquake ground motions were used for the input motions: the design earthquake ground motion for the Korean nuclear power plants, the scenario earthquakes for Korean nuclear power plant sites, and the near-fault earthquake record from the Chi-Chi earthquake. The probability-based scenario earthquakes were developed for the Korean nuclear power plant sites using the PSHA data. A 4-story steel frame structure was fabricated to perform the tests. Test results showed that the high frequency ground motions of the scenario earthquake did not damage the structure at the nuclear power plant site; however, the ground motions had a serious effect on the equipment installed on the high floors of the building. This shows that the design earthquake is not conservative enough to demonstrate the actual danger to safety related nuclear power plant equipment.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2002.03a
• /
• pp.42-50
• /
• 2002

The duration and H/V ratio(the amplitude ratio of the horizontal to vertical components) of ground motions caused by earthquakes in southern Korea are analyzed. Total 329 seismograms of horizontal component recorded at hypocentral distances of 10 to 350 km from 27 earthquakes with local magnitude 2 to 4 are used for the analysis. Simplified relation between the duration of ground motion( $T_{d}$) and the ratio($\chi$) of Arias intensity( $I_{A}$) and squared maximum acceleration($\alpha$$_{max}$$^{2}$) is determined to be $T_{d}$ = 3.423$\chi$$^2$+ 8.200$\chi$ + 0.029, which is useful for the estimation of the duration in southern Korea. There are three distinct distance ranges with different linear variations of the duration in hypocentral distance. They are distance intervals of 10~80km, 80~140km, and the distance greater than 140km. The duration in southern Korea shows clear proportionality to the local magnitude at magnitudes greater than 3.1. The value 1.37 of the H/V ratio obtained in southern Korea is similar to the value 1.4 of ENA(Eastern North America). The H/V ratio in southern Korea increases in the frequency range from 0.3 to 10Hz. The duration and H/V ratio of ground motions derived in this study could be used in the stochastic simulation of strong ground motion.ion.n.n.

• Structural Engineering and Mechanics
• /
• v.31 no.3
• /
• pp.241-264
• /
• 2009

In this paper, the dynamic behavior for a group of transmission towers linked together through electrical wires and subjected to a strong ground motion will be investigated in detail. In performing the seismic analysis, the wires and the towers concerned are modeled, respectively, by using the efficient cable elements and the 3-D beam elements both considering geometric nonlinearities. In addition, to enhance the reliability and applicability of analytical outcome, a sophisticated soil-structure interaction model will be utilized in analyses. The strength capacities and the fracture occurrences for the main members of the tower are examined with the employment of the appropriate strength interaction equations. It is expected that by aid of this investigation, those who are engaged in code constitution or in practical designing of transmission towers may gain a better insight into the roles played by the interaction force between towers and wires and by the configurations of transmission lines under strong earthquake.