• Journal of the Earthquake Engineering Society of Korea
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• 제22권7호
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• pp.361-367
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• 2018

This study investigates the seismic performance of a hybrid seismic energy dissipation device composed of a viscoelastic damper and a steel slit damper connected in parallel. A moment-framed structure is designed without seismic load and is retrofitted with the hybrid dampers. The model structure is transformed into an equivalent simplified system to find out optimum story-wise damper distribution pattern using genetic algorithm. The effectiveness of the hybrid damper is investigated by fragility analysis of the structure with and without the dampers. The analysis results show that after seismic retrofit the probability of reaching damage states, especially the complete damage state, of the structure turn out to be significantly reduced.

• Computers and Concrete
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• 제2권2호
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• pp.147-164
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• 2005

This paper summarizes an experimental study on the seismic behavior of lower stories of a mid-rise reinforced concrete frame building. Two reinforced concrete frames with two stories and one span were tested and each frame represents lower two stories of an 11-story RC frame building. Both frames were designed in accordance with Japanese design guidelines and were identical except in the variation of axial force. The tests demonstrated that the overall load-displacement relations of the two frames were nearly the same and the first-story column shear was closely related to the column axial load. The columns and beams elongated during both of the tests, with the second-floor beam elongation exceeding 1.5% of the beam clear span length. The frame with higher axial loads developed more cracks that the frame under moderate axial load.

• Proceedings of the Korean Geotechical Society Conference
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.484-491
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• 2008

The purpose of this study is to compare the cementation effect on cone resistance and DMT indices and to evaluate the deformation characteristic of cemented sand using cone resistance and dilatometer modulus. Specimens of various relative densities with three different cementation levels are prepared in a large calibration chamber under different vertical stress levels. Test result shows that the cone resistance and dilatometer modulus underestimate the deformation modulus of cemented sand, since in situ penetration tests such as CPT and DMT damage the cementation bonds during penetration. By regression analysis, the constrained modulus of cemented sand is related with the cone resistance and the dilatometer modulus.

• 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.

• International conference on construction engineering and project management
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.235-242
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• 2013

With the recent global trends in environmental preservation, the importance of sustainable construction is being highlighted in Korea. In particular, the trend is being discussed about life cycle of the apartment houses in various aspects. However the Korean construction market and housing policy have been increasingly focusing on supplier. Structures become progressively obsolete after a certain period, but their durability can be extended with proper maintenance management. Accordingly, if maintenance management on the structures is made efficiently, waste of construction energy and damage to the environment and economic loss due to early demolition and reconstruction can be effectively prevented. Therefore, this study aims to suggest the user manual design for the efficient maintenance in apartment housing

• Journal of the Earthquake Engineering Society of Korea
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• 제22권3호
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• pp.103-111
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• 2018

This study examines the seismic failure of RC low-rise building structures having irregularities at the ground story during the 15 November 2017 Pohang, Korea, earthquake, $M_w=5.4$, which is the second strongest since the government began monitoring them in 1978 in South Korea. Some 2,000 private houses were damaged or destroyed in this earthquake. Particularly, serious damage to the piloti story of RC low-rise residential building structures of fewer than five stories was observed within 3 km of the epicenter with brittle shear failure of columns and walls due to severe torsional behavior. Buildings below six stories constructed before 2005 did not have to comply with seismic design requirements, so confinement detailing of columns and walls also led to inadequate performance. However, some buildings constructed after 2005 were damaged at the flexible side of the piloti story due to the high torsional irregularity. Based on these results, this study focuses on the problems of the seismic torsion design approach in current building codes.

• International Journal of Concrete Structures and Materials
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• 제9권2호
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• pp.133-143
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• 2015

This paper describes the test results and nonlinear analysis of reinforced concrete T-beams strengthened by bonded steel plates under increasing static loading conditions. The first part of this paper discusses the flexural tests on five T-beams, including the test model design (based on similarity principles), test programs, and test procedure. The second part discusses the nonlinear numerical analysis of the strengthened beams, in which a concrete damage plasticity model and a cohesive behavior were adopted. The numerical analysis results are compared with experimental data and show good agreement. The area of bonded steel plate and the anchor bolt spacing were found to have an impact on the cracking load, yield load, and ultimate load. An increase in the area of steel plate and a reduction of the anchor spacing could significantly improve the cracking and ultimate loads and decrease the damage of the beam.

• Journal of Korean Society of Steel Construction
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• 제25권4호
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• pp.441-449
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• 2013

Damaged structures change the value of natural properties. The purpose of this study is to detect damage using the difference of natural properties between the healthy state and the damaged state. Anti-optimization method is used to find the conditions that maximize the difference in characteristics between the two contrasting models. In this paper, a algorithm for finding the loading conditions which can maximize the difference of strain energy between the healthy state and the damaged state of truss structures is developed. Numerical examples show that the proposed method is accurate and efficient for truss structures.

• International Journal of Concrete Structures and Materials
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• 제1권1호
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• pp.29-36
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• 2007

The purpose of this paper is the assessment of the capacity of the reinforced concrete (RC) elements of an arch bridge when they are subjected to contact and near-contact explosive charges of various amounts, and the estimation of the critical charges for these components. The bridge considered is the Tenza Viaduct, a decommissioned structure south of Naples, Italy. Its primary elements, deck, piers and arches were analyzed. The evaluation was accomplished via numerical analyses that made possible to obtain the elements dynamic response when they are exposed to blast loading conditions. To evaluate the member's capacities, failure criteria for deck, piers and arches were proposed based on concrete damage parameters. Additionally, curves relating the explosive charge to the residual capacity and to damage level of the elements were also developed. The results of this work were taken into account to investigate the progressive collapse of the global structure.

• Journal of the Architectural Institute of Korea Structure & Construction
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• 제33권12호
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• pp.3-10
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• 2017

Climate change not only has various impacts such as human shoes, economics, the environment, industry, etc. but the damage caused by this is also increasing, it is expected that severe damage will not occur without efforts to respond to climate change ing. Therefore, as the impact of climate change like the extreme weather phenomenon is dailyized and its strength tends to become stronger, as much as the mitigation measures of climate change, as a comparative effort to reduce the negative impact of climate change, adaptation to climate change is necessary. Especially when the damage caused by climate change (intense heat, torrential rain, cold wave and heavy snow etc.) as an institution responsible for the provision of public services such as public institutions, the socio-economic spread to the nation and the people The effect is very large. We confirmed the level of response to climate change for the entire public institution, and selected climate change risk which is relatively important for specific facilities and business establishments of public institutions, climate change adaptation measures We will try to utilize it as basic material of establishment.