• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.3
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• pp.111-119
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• 1998

This paper reports a part of research work on earthquake resistance consideration in regions of moderate seismicity, which is being carried out in the Department of Civil Engineering, Hong Kong University of Science & Technology. The possible seismic hazard in Hong Kong, which is located in a region of moderate seismicity, is described. A case study is presented to compare the wind and earthquake effects on Hong Kong buildings and to assess whether seismic analysis and desing is necessary for building structure. Potential problems of reinforced concrete buildings under earthquake effects in regions of moderate seismicity are discussed.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.3
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• pp.99-109
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• 1998

Korea is located in either low of moderate seismicity continental region. It is realized that the design codes and underlying design concept of high seismicity region may not be a, pp.opriate to low and moderate seismicity regions. The aim of this paper is to search seismic design concept that is deemed to be a, pp.opriate to low and moderate seismicity regions. To this end, the seismicity of Korea will be introduce first and important aspects of seismic design in moderate seismicity region will be discussed. The two-level code system that is going to be adopted in the future seismic regulations of Korea will be introduced.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.2
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• pp.77-86
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• 2018

This study develops an empirical prediction equation of spectral acceleration responses of earthquakes which can induce structural damages. Ground motion records representing hazards of low-to-moderate seismic regions were selected and organized with several influential factors affecting the response spectra. The empirical equation and estimator coefficients for acceleration response spectra were then proposed using a robust nonlinear optimization coupled with a regression analysis. For analytical verification of the prediction equation, response spectra used for low-to-moderate seismic regions were estimated and the predicted results were comparatively evaluated with measured response spectra. As a result, the predicted shapes of response spectra can simulate the graphical shapes of measured data with high accuracy and most of predicted results are distributed inside range of correlation of variation (COV) of 30% from perfectly correlated lines.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.217-222
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• 1999

Seismic design in low to moderate seismic regions has to be based on the characteristics of seismic risk ground motion and structural response in that region. The characteristics of seismic hazard in low to moderate seismic regions are reviewed briefly. The recent findings on the dynamic behavior subjected to the moderate intensity level of ground motion are summarized. The seismic design considerations in Easterm America China Australia Thailand and Hong Kong will be introduced, . The effort to adopt the limited ductility design in low to moderate seismicity regions will be reported. Finally research works that are required for the implementation of the limited design concept will be proposed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.75-84
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• 1998

Korea is located in either low or moderate seismicity continental region. It is realized that design codes and underlying design concepts of high seismicity region may not be appropriate to low or moderate seismicity region. In this paper, test results on the seismic response of structures without seismic detailing are reexamined and compared with numerical analysis results. The seismic design concept based on limited ductility is proposed as an alternative seismic design approach in moderate seismicity regions.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.3
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• pp.121-127
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• 1998

For the seismic design of bridges in Korea classified as the low to moderate seismic zones, the design concepts provided in the Standard Specification for Highway Bridges, Division I-A: Seismic Design, are adopted, which is basically developed for the strong seismic zones by AASHITO. Accordingly, the design procedures provided for the low to moderate seismic zones are simplified too much to fulfill the purpose of the seismic design. In this paper the design procedures given for the low to moderate seismic zones in the Standard are summarized and discussed in view of the seismic design purpose. From the discussion results some revisions are proposed as conclusions for the reasonable a, pp.ication of the Standard for bridges located in the low to moderate seismic zones.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.292-299
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• 2002

It has been realized that the design codes and underlying design concept of high seismicity region may not be appropriate to low and moderate seismicity regions. The aim of this paper is to search seismic design strategies that are appropriate to moderate seismicity regions. The characteristics of seismic hazard in moderate seismicity regions are reviewed. The seismic responses of multi-span continuous bridges subjected to the ground shaking of moderate intensity are examined. The present code on seismic design of bridges is briefly reviewed. Based on these observations, design principles and strategies appropriate to the moderate seismicity regions are proposed for the multi-span continuous bridge

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.359-366
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• 1999

This paper is a study on the seismic design and test of viscoelastic dampers in regions of moderate seismicity. First moderate seismic waves are generated with measured strong seismic data based on the theory of effective peak acceleration. Then their response spectrums are compared each other to estimate the required damping to attenuate the vibration. As relatively smaller damping is required in the regions of moderate seismicity than in the regions of strong seismicity proper viscoelastic dampers can be designed according to the estimated damping. Finally a test building model is designed and the viscoelastic dampers are installed for the experimental study under moderate and strong earthquakes, It is found that viscoelastic dampers with low damping capacity developed in this study are enough to reduce the building response in regions of moderate seismicity.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.569-576
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• 2003

Based on the equivalent uniform stress concept Presented by Seed and Idriss, sinusoidal cyclic loads which simplified earthquake loads have been applied in evaluating the liquefaction resistance strength experimentally. However, the liquefaction resistance strength of soil based on the equivalent uniform stress concept can not exactly reflect the dynamic characteristics of the irregular earthquake motion. The liquefaction assessment method which was invented by using the equivalent uniform stress concept is suitable for the severe earthquake region such as Japan or USA, so the proper method to Korea is needed. In this study, estimation of the resistance to liquefaction was conducted by applying real earthquake loading to the cyclic triaxial test. From the test results, the characteristics of the fine sand under moderate earthquake were analyzed and compared with the results under strong earthquakes. Typically real earthquake loads used in this study are divided into two types - impact type and vibration type. Furthermore, results of the liquefaction resistance strength based on the equivalent uniform stress concept and tile concept using real earthquake loading were compared.

• Earthquakes and Structures
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• v.17 no.4
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• pp.355-363
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• 2019

Masonry structures in the rural areas of Turkey often damaged due to moderate and big earthquakes. After every earthquake many scientists made field investigations on the earthquake performance of these structures and gave many useful information on construction techniques. However, the newly constructed masonry buildings are still not suitable for the suggested techniques, and they are still in danger against future earthquakes. Five moderate earthquakes of moment magnitude Mw 5.3, 5.3, 5.2, 5.0, and 5.3 struck the Ayvacik-Çanakkale District of Turkey between 6 and 12 February, 2017. More than a thousand of aftershocks were occurred and most of the masonry buildings in the villages nearby main shock epicenter were affected. The author went to the earthquake field and investigated the earthquake performances of masonry structures. This paper presents the recorded acceleration data, acceleration response spectra, and the seismological aspects of these earthquakes. Besides, case studies of damaged stone masonry buildings, and failure mechanisms are discussed with illustrated photos which were taken during the field investigations. It is concluded that the damaged masonry buildings were not designed and constructed properly in accordance with the Turkish building codes or similar specifications.