• Architectural research
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• 제20권1호
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• pp.17-25
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• 2018

Countermeasures against earthquake disasters such as the seismic capacity evaluation and/or retrofit schemes of buildings, especially existing low-rise reinforced concrete buildings, have not been fully performed since Korea had not experienced many destructive earthquakes in the past. However, due to more than 1200 earthquakes with low or moderate intensity in the off-coastal and inland of Korea during the past 20 years, and due to the recent moderate earthquakes in Korea, such as the 2016 Gyeongju Earthquake with M=5.8 and the 2017 Pohang Earthquake with M=5.4, the importance of the future earthquake preparedness measures is highly recognized in Korea. The main objective of this study is to provide the basic information regarding seismic capacities of existing low-rise reinforced concrete buildings in Korea. In this paper, seismic capacities of 14 existing low-rise reinforced concrete public buildings in Korea are evaluated based on the Japanese Standard for Evaluation of Seismic Capacity of Existing Reinforced Concrete Buildings. Seismic capacities between existing buildings in Korea and those in Japan is compared, and the relationship of seismic vulnerability of Korean buildings and Japanese buildings damaged due to severe earthquakes are also discussed. Results indicated that Korean existing low-rise reinforced concrete buildings have a narrow distribution of seismic capacities and they are relatively lower than Japanese buildings, and are also expected to have severe damage under the earthquake intensity level experienced in Japan. It should be noted from the research results that the high ductility in Korean existing low-rise buildings obtained from the Japanese Standard may be overestimated, because most buildings investigated herein have the hoop spacing wider than 30 cm. In the future, the modification of strength and ductility indices in the Japanese Standard to propose the seismic capacity evaluation method of Korean buildings is most needed.

• Advances in concrete construction
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• 제10권4호
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• pp.333-343
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• 2020

In the architectural design process, the selection and configuration of the structural system significantly affect the earthquake behaviours of the reinforced concrete buildings. The main purpose of this study, the effects on the earthquake performances and the rough construction cost of the buildings of the slab type in reinforced concrete buildings are to examine comparatively for different local soil classes. The results obtained from this study have been determined that the building model having slabs with beams is safer compared to other types of slabs, especially when considering the vertical bearing structural elements (columns). It also shows that other types of slab, except for slab with beams, reduce the earthquake performances of reinforced concrete buildings, increase the displacement values, 1st natural vibration period values and the cost of rough construction. This matter reveals that slab type is quite important and the preference of beamed slabs in reinforced concrete buildings to be constructed in earthquake zones would be more appropriate in terms of safety and cost.

• Earthquakes and Structures
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• 제8권1호
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• pp.133-152
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• 2015

This paper investigates the soil effect on seismic behaviour of reinforced concrete (RC) buildings by using the spread plastic hinge model which includes material and geometric nonlinearity of the structural members. Therefore, typical reinforced concrete frame buildings are selected and nonlinear dynamic time history analyses and pushover analyses are performed. Three earthquake acceleration records are selected for nonlinear dynamic time history analyses. These records are adjusted to be compatible with the design spectrum defined in Turkish Seismic Code. Interstory drifts and damages of selected buildings are compared according to local soil classes. Also, capacity curves of these buildings are compared with maximum responses obtained from nonlinear dynamic time history analyses. The results show that, soil class influences the seismic behaviour of reinforced concrete buildings, significantly.

• Earthquakes and Structures
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• 제11권5호
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• pp.873-885
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• 2016

Determination of earthquake-safety of existing buildings requires a rather long and challenging process both in terms of time and expertise. In order to prevent such a tedious process, rather rapid methods for evaluating buildings were developed. The purpose of these rapid methods is to determine the buildings that have priority in terms of risk and accordingly to minimize the number of buildings to be inspected. In these rapid evaluation methods detailed information and inspection are not required. Among these methods the Canadian Seismic scanning method and the first stage evaluation method included in the principles concerning the determination of risk-bearing buildings promulgated by the Ministry of Environment and Urbanization in Turkey are used in the present study. Within the scope of this study, six reinforced concrete buildings damaged in Van earthquakes in Turkey are selected. The performance scores of these buildings are calculated separately with the mentioned two methods, and then compared. The purpose of the study is to provide information on these two methods and to set forth the relation they have between them in order to manifest the international validity.

• 한국지진공학회논문집
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• 제25권4호
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• pp.161-168
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• 2021

Existing old reinforced concrete buildings could be vulnerable to earthquakes because they were constructed without satisfying seismic design and detail requirements. In current seismic design standards, the target collapse probability for a given Maximum Considered Earthquake (MCE) ground-shaking hazard is defined as 10% for ordinary buildings. This study aims to estimate the collapse probabilities of a three-story, old, reinforced concrete building designed by only considering gravity loads. Four different seismic design categories (SDC), A, B, C, and D, are considered. This study reveals that the RC building located in the SDC A region satisfies the target collapse probability. However, buildings located in SDC B, C, and D regions do not meet the target collapse probability. Since the degree of exceedance of the target probability increases with an increase in the SDC level, it is imminent to retrofit non-ductile RC buildings similar to the model building. It can be confirmed that repair and reinforcement of old reinforced concrete buildings are required.

• Earthquakes and Structures
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• 제20권3호
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• pp.309-323
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• 2021

Architectural design decisions and structural systems arrangements affect their earthquake behaviors significantly of reinforced concrete building in Turkey. Because the performances as safe and economical against earthquake loads of reinforced concrete buildings can be provided with especially design decisions in the architectural design stage. This matter reveals the importance of design decisions in the architectural design phase and the right structural system arrangement. The purpose of this study, the short-column situation frequently observed in reinforced concrete buildings after the earthquakes occurred in Turkey are to examine comparatively the effects on behavior and the rough construction cost of the building. The obtained results show that the short column circumstance composed due to different reasons negatively affects the earthquake performance of the reinforced concrete buildings and increases the rough construction cost. This matter shows that the measures to be taken against short column formation should be foreseen especially at the architectural design stage.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.148-151
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• 2003

This paper concerns the seismic performance index of highrise reinforced concrete shear wall buildings assessed by FEMA 273 and ATC-40 provisions. The applied buildings are 10 to 35 stories and the evaluation level is life safety level. The seismic performance index results of $1^{st}$ and $2^{nd}$ evaluations are as follows; (equation omitted)

• 한국지진공학회논문집
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• 제20권3호
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• pp.145-153
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• 2016

Small-size buildings are not designed by professional structural engineers in Korea. Therefore, their seismic performance can not be exactly estimated because their member sizes and reinforcement may be over- or under-designed. A prescriptive design criteria for the small-size buildings exists, but it also provides over-designed structural members since structural analysis is not incorporated, so it is necessary to revise the prescriptive criteria. The goal of this study was to provide an information for the revision, which is seismic performance and capability of small-size reinforced concrete moment frame buildings. For the study, the state of existing small-size reinforce-concrete buildings such as member size and reinforcement was identified by investigating their structural drawings. Then, over-strength, ductility and response modification factor of the small-size reinforced concrete moment frame buildings were estimated by analytical approach along with seismic performance check. The result showed that they possess moderate over-strength and ductility, and may use slightly increased response modification factor.

• Structural Engineering and Mechanics
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• 제50권3호
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• pp.383-401
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• 2014

Over the past years, hybrid building systems, consisting of reinforced concrete frames in bottom and steel frames in top are used as a cost-effective alternative to traditional structural steel or reinforced concrete constructions. Dynamic analysis of hybrid structures is usually a complex procedure due to various dynamic characteristics of each part, i.e. stiffness, mass and especially damping. In hybrid structures, one or more transitional stories with composite sections are used for better transition of lateral and gravity forces. The effect of transitional storey has been considered in no one of the studies in the field of hybrid structures damping. In this study, a method has been proposed to determining the equivalent modal damping ratios for hybrid steel-concrete buildings with transitional storey. In the proposed method, hybrid buildings are considered to have three structural systems, reinforced concrete, composite steel and concrete (transitional storey) and steel system. In this method, hybrid buildings are substituted appropriately with 3-DOF system.

• Structural Engineering and Mechanics
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• 제41권4호
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• pp.479-494
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• 2012

This study explores a coefficient-based seismic capacity assessment method with a special emphasis on low-rise masonry in-filled (MI) reinforced concrete (RC) buildings subjected to earthquake motion. The coefficient-based method without requiring any complicated finite element analysis is a simplified procedure to assess the maximum spectral acceleration capacity of buildings. This paper first compares the fundamental periods of MI RC structures obtained, respectively, from experimental period data and empirical period-height formulas. The coefficient-based method for low-rise masonry buildings is then calibrated by the published experimental results obtained from shaking table tests. The comparison of the experimental and estimated results indicates that the simplified coefficient-based method can provide good approximations of the maximum spectral accelerations at peak loads of the low-rise masonry reinforced concrete buildings if a proper set of drift factors and initial fundamental vibration periods of structures are used.