• Journal of Korean Elementary Science Education
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• v.17 no.1
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• pp.33-46
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• 1998

This study researched the concepts that elementary school students have after having learned volcano and earthquake. The reacher collected and adjusted the journals related to this study, and sampled the concepts included in Chap. One "Moving Earth", the first term of the elementary school sixth year. The students' descriptive responses were analyzed after subjective questions on the basis of above were developed and put into. After the contents described in the answer sheets were categorized by key words and the types of concept were made out by qualitative analysis, it was showed what was differences between the sexual, regional and achievement levels. The results of this study were as follows; first, though the types of concept about volcano and earthquake were found variably, it was showed that wrong preconception was not corrected, especially the exact understanding about terms not attained to, which led to the trouble in conceptual readjustment of students. Second, though the response rate about the types of scientific concept was found high that volcano was made out of explosion and eruption of magma and lava, there were also children who described not the interior factor of globe but the surface factor. Third, according to the results divided into the interior factor of globe and the surface factor and analyzed about earthquake, there were a great number of children who responded as the surface factor though most of the students responded to the interior factor of globe. Fourth, through some types of concept, it was found that the formation of concept was much influenced by experience of children's life, curriculum, and the method of study. Fifth, In the most test question, the scientific concept was found that boys were higher than girls in the distinction of sex, the children of cities than those of town and island, and the upper group than the lower group in the achievement levels.

• Earthquakes and Structures
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• v.25 no.1
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• pp.1-13
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• 2023

Reinforced concrete (RC) moment frames are used as lateral seismic load resisting systems in mid- and high-rise buildings in different regions of the world. Based on the seismic design provisions and construction details presented in design codes, RC frames with different levels of ductility (ordinary, intermediate, and special) can be designed and constructed. In Iran, there are RC buildings with various uses which have been constructed based on different editions of design codes. The seismic performance of RC structures (particularly moment frames) in real seismic events is of great importance. In this paper, the observations made on damaged RC moment frames after the destructive Sarpol-e Zahab earthquake with a moment magnitude of 7.3 are reported. Different levels of damage from the development of cracks in the structural and non-structural elements to the total collapse of buildings were observed. Furthermore, undesirable failure modes which are not expected in ductile seismic-resistant buildings were frequently observed in the damaged buildings. The RC moment frames built based on the previous editions of the design codes showed partial or total collapse in this seismic event. The extensive destruction of RC moment frames compared with the other structural systems (such as braced steel frames and confined masonry buildings) was attributed not only to the deficiencies in the construction practice of these buildings but also to the design procedure. In addition, the failure and collapse of masonry infills in RC moment frames were frequent modes of failure in this seismic event. In this paper, the main reasons related to design practice which led to extensive damage in the RC moment frames and their collapse are addressed.

• Structural Engineering and Mechanics
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• v.88 no.2
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• pp.117-128
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• 2023

On February 6, 2023, Türkiye woke up with a strong ground motion felt in a wide geography. As a result of the Kahramanmaraş, Pazarcık and Elbistan earthquakes, which took place 9 hours apart, there was great destruction and loss of life. The 2023 Kahramanmaraş earthquakes occurred on active faults known to pose a high seismic hazard, but their effects were devastating. Seismic code spectra were investigated in Hatay, Adıyaman and Kahramanmaraş where destruction is high. The study mainly focuses on the investigation of ground motion parameters of 6 February Kahramanmaraş earthquakes and the correlation between ground motion parameters. In addition, earthquakes greater than Mw 5.0 that occurred in Türkiye were compared with certain seismic parameters. As in the strong ground motion studies, seismic energy parameters such as Arias intensity, characteristic intensity, cumulative absolute velocity and specific energy density were determined, especially considering the duration content of the earthquake. Based on the study, it was concluded that the structures were overloaded far beyond their normal design levels. This, coupled with significant vertical seismic components, is a contributing factor to the collapse of many buildings in the area. In the evaluation made on Arias intensity, much more energy (approximately ten times) emerged in Kahramanmaraş earthquakes compared to other Türkiye earthquakes. No good correlation was found between moment magnitude and peak ground accelerations, peak ground velocities, Arias intensities and ground motion durations in Türkiye earthquakes. Both high seismic components and long ground motion durations caused intense energy to be transferred to the structures. No strong correlation was found between ground motion durations and other seismic parameters. There is a strong positive correlation between PGA and seismic energy parameter AI. Kahramanmaraş earthquakes revealed that changes should be made in the Turkish seismic code to predict higher spectral acceleration values, especially in earthquake-prone regions in Türkiye.

• Earthquakes and Structures
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• v.5 no.5
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• pp.553-570
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• 2013

Using of masonry infill as partitions, in flat slab frame buildings is a common practice in many parts of the world. The infill is, generally, not considered in the design and the buildings are designed as bare frames. More of fundamental information in the effect of masomary infill on the seismic performance of RC building frames is in great demand for structural engineers. Therefore the main aim of this research is to evaluate the seismic performance of such buildings without (bare frame) and with various systems of the masonary infill. For this purpose, thirteen three dimensional models are chosen and analyzed by SAP2000 program. In this study the stress strain relation model proposed by Crisafulli for the hysteric behaviour of masonary subjected to cyclic loading is used. The results show that the nonstructural masonary infill can impart significant increase global strength and stiffness of such building frames and can enhance the seismic behaviour of flat slab frame building to large extent depending on infill wall system. As a result great deal of insight has been obtained on seismic response of such flat slab buildings which enable the structural engineer to determine the optimum position of infill wall between the columns.

• Journal of Korean Association for Spatial Structures
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• v.14 no.3
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• pp.101-108
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• 2014

Recently, natural disasters such as earthquake, tsunami, typhoon and tornado are increasing, and cause huge economical loses and victim. Thus, when the disaster occurs, it is important to prepare emergency evacuation shelters for fast and easy construction compared to general building system. And, deployable structures will provide a great help for such aim. Deployable structures have the great advantage of being faster and easier to erect and dismantle compared to conventional building forms. In this study, we confirm the possibility of deployment for shelter structures using scissor structure system. First, Basic model was performed to recognize the appllicability of the deployable systems of the dome-shaped structure. Second, Advanced model that more improved inner space and deployment mechanism was confirmed.

• International Journal of High-Rise Buildings
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• v.1 no.3
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• pp.195-201
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• 2012

Today, a great effort to develop PBSD procedure to be utilized in Korea is given by domestic structural engineers, academics, and governmental organizations. After Great East Japan Earthquake (2011) took place, lots of clients in Korea became to concern of their buildings so that requests of seismic performance evaluation and seismic rehabilitation for existing buildings have been gradually increased. Such interests in seismic events initiated a rapid development of a series of guidelines for seismic performance evaluation and seismic performance enhancement. For new buildings, however, design guidelines for PBSD are yet well prepared in Korea and prescriptive design methods are dominant design procedure still. Herein, seismicity demands used in seismic performance evaluation and some important design parameters in NLRH are introduced. Some project examples for seismic performance evaluation and rehabilitation applying passive energy dissipation devices are also described in the latter part of paper.

• Earthquakes and Structures
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• v.19 no.4
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• pp.287-301
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• 2020

Fragility as one of the most effective methods to evaluate seismic performance, which is greatly affected by damage index. Taking a multi span continuous rigid frame offshore bridge as an example. Based on fragility and reliability theory, considering coupling effect of time-varying durability damage of materials and time-varying attenuation effect of damage index to analyze seismic performance of offshore bridges. Results show that IDA curve considering time-varying damage index is obviously below that without considering; area enclosed by IDA of 1# pier and X-axis under No.1 earthquake considering this effect is 96% of that without considering. Area enclosed by damage index of 1# pier and X-axis under serious damage with considering time-varying damage index is 90% of that without considering in service period. Time-varying damage index has a greater impact on short pier when ground motion intensity is small, while it has a great impact on high pier when the intensity is large. The area enclosed by fragility of bridge system and X-axis under complete destruction considering time-varying damage index is 165% of that without considering when reach designed service life. Therefore, time-varying attenuation effect of damage index has a great impact on seismic performance of bridge in service period.

• Earthquakes and Structures
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• v.25 no.3
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• pp.209-221
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• 2023

The Mw=7.7 (Pazarcık-Kahramanmaraş) and Mw=7.6 (Elbistan-Kahramanmaraş) earthquakes that occurred in Türkiye on 06.02.2023 with 9 hours' intervals, caused great losses of life and property as the biggest catastrophe in the instrumental period. The earthquakes affecting an area of 14% of the country were enormous and caused a great deal of loss of life and damage. Numerous buildings have collapsed or damaged at different levels, both in the city centers and in rural areas. Within the scope of this study, masonry structure damage built from different types of materials in the earthquake region was taken into consideration. In this study, the damage and causes of such masonry structures that do not generally receive engineering services were examined and explained in detail. Insufficient interlocking between wall-wall and wall-roof, inadequate masonry, lack of horizontal and vertical bond beams, usage of low-strength materials, poor workmanship, and heavy earthen roof are commonly caused to structural damages. Separation at the corner point and out-of-plane mechanism in structural walls, and heavy earthen roof damages are common types of damage in masonry structures.

• Electronics and Telecommunications Trends
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• v.35 no.1
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• pp.80-88
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• 2020

This paper describes the development trends and service provision examples of disaster occurrence and spread prediction technology for various disasters such as tsunamis, floods, and fires. In terms of fires, we introduce the WIFIRE system, which predicts the spread of large forest fires in the United States, and the Metro21: Smart Cities Institute project, which predicts the risk of building fires. This paper describes the development trends in tsunami prediction technology in the United States and Japan using artificial intelligence (AI) to predict the occurrence and size of tsunamis that cause great damage to coastal cities in Japan, Indonesia, and the United States. In addition, it introduces the NOAA big data platform built for natural disaster prediction, considering that the use of big data is very important for AI-based disaster prediction. In addition, Google's flood forecasting system, domestic and overseas earthquake early warning system development, and service delivery cases will be introduced.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.185-190
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• 2001

The severe shortage of the available sites in the highly developed downtown area in Korea necessitates the construction of high-rise buildings which meet the need of residence and commercial activity simultaneously. The objective of this study is to investigate the seismic performance of this type of building structures. For this purpose, two 1:12 scale 17-story reinforced concrete model structures were constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2-story frames with infilled shear wall have two different layouts of the plan : The one has symmetric plan and the other has unsymmetric plan. Then, this model was subjected to a series of earthquake excitations. The test results show that the layout of shear wall has the negligible effect on the natural period and the base shear coefficient, but great effect on the failure mode of beam-column joint at flexible side frame.