설계스펙트럼의 개정에 따른 철근콘크리트 보통모멘트골조의 내진성능수준 평가

심정은,김준희 한국지진공학회 2022 한국지진공학회논문집 Vol.26 No.5

New buildings have been designed using different seismic design standards that have been revised. However, the seismic performance of existing buildings is evaluated through the same performance evaluation guidelines. Existing buildings may not satisfy the performance targets suggested in the current guidelines, but there are practical limitations to discriminating the existing buildings with poor seismic performance through a full investigation. In this regard, to classify buildings with poor seismic performance according to the applied standard, this study aimed to evaluate performance-based investigation of the seismic design proposals of buildings with different design standards. The target buildings were set as RC ordinary moment frames for office occupancy. Changes in seismic design criteria by period were analyzed, and the design spectrum changes of reinforced concrete ordinary moment resisting frames were compared to analyze the seismic load acting on the building during design. The seismic design plan was derived through structural analysis of the target model, compared the member force and cross-sectional performance, and a preliminary evaluation of the seismic performance was performed to analyze the performance level through DCR. As a result of the seismic performance analysis through the derived design, the reinforced concrete ordinary moment frame design based on AIK 2000 has an insufficient seismic performance level, so buildings built before 2005 are likely to need seismic reinforcement.

Integrated analysis model for assessing CO₂ emissions, seismic performance, and costs of buildings through performance-based optimal seismic design with sustainability

Park, Hyo Seon,Hwang, Jin Woo,Oh, Byung Kwan Elsevier 2018 Energy and buildings Vol.158 No.-

<P><B>Abstract</B></P> <P>An integrated sustainable seismic analysis model is developed to investigate the relationships of CO<SUB>2</SUB> emissions, the seismic performance, and material production costs of seismic design schemes of buildings. In this study, a green seismic analysis model is presented in the form of performance-based optimal seismic design with sustainability (PBODS) that considers the economic feasibility, environmental sustainability, and seismic performance of a building based on the life cycle assessment (LCA) data subject to various performance objectives prescribed in performance-based seismic engineering. This analysis model is applied to reinforced concrete (RC) frame buildings, which comprise two heterogeneous materials—concrete and steel—that have different environmental impacts and thus have a high potential for CO<SUB>2</SUB> emission mitigation. In the PBODS method presented in this study, CO<SUB>2</SUB> emissions, material production costs, and the coefficient of variation (COV) of the inter-story drift ratio, which reflects the seismic performance, are set as the objective functions, and optimal designs that can minimize these three objective functions. The optimal designs for a 4-story and a 10-story RC buildings are then evaluated with respect to environmental sustainability, economic feasibility, and seismic performance using the presented integrated analysis model. Furthermore, the proposed model is used to quantitatively investigate the variations in CO<SUB>2</SUB> emissions and material production costs depending on variations in the performance objectives.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An integrated sustainable seismic analysis model for evaluating environmental impacts of seismic designs of buildings for various performance objectives is presented. </LI> <LI> In the model, a green seismic analysis model is presented in the form of performance-based optimal seismic design with sustainability (PBODS) to derive optimal design schemes. </LI> <LI> Environmental impacts and costs of low- and mid-rise buildings are quantitatively analyzed depending on performance objectives. </LI> <LI> Dominant design constraints for PBODS are examined according to the building size and performance objective. </LI> </UL> </P>

기계학습 기반 지진 취약 철근콘크리트 골조에 대한 신속 내진성능 등급 예측모델 개발 연구

강태욱,강재도,오근영,신지욱 한국지진공학회 2024 한국지진공학회논문집 Vol.28 No.4

Existing reinforced concrete (RC) building frames constructed before the seismic design was applied have seismically deficient structural details, and buildings with such structural details show brittle behavior that is destroyed early due to low shear performance. Various reinforcement systems, such as fiber-reinforced polymer (FRP) jacketing systems, are being studied to reinforce the seismically deficient RC frames. Due to the step-by-step modeling and interpretation process, existing seismic performance assessment and reinforcement design of buildings consume an enormous amount of workforce and time. Various machine learning (ML) models were developed using input and output datasets for seismic loads and reinforcement details built through the finite element (FE) model developed in previous studies to overcome these shortcomings. To assess the performance of the seismic performance prediction models developed in this study, the mean squared error (MSE), R-square (R2), and residual of each model were compared. Overall, the applied ML was found to rapidly and effectively predict the seismic performance of buildings according to changes in load and reinforcement details without overfitting. In addition, the best-fit model for each seismic performance class was selected by analyzing the performance by class of the ML models.

State of Practice of Performance-Based Seismic Design in Korea

Lee, Dong-Hun,Kim, Taejin,Kim, Jong-Ho,Kang, Dae-Eon Council on Tall Building and Urban Habitat Korea 2012 International journal of high-rise buildings Vol.1 No.3

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.

Seismic Performance of High-rise Concrete Buildings in Chile

Lagos, Rene,Kupfer, Marianne,Lindenberg, Jorge,Bonelli, Patricio,Saragoni, Rodolfo,Guendelman, Tomas,Massone, Leonardo,Boroschek, Ruben,Yanez, Fernando Council on Tall Building and Urban Habitat Korea 2012 International journal of high-rise buildings Vol.1 No.3

Chile is characterized by the largest seismicity in the world which produces strong earthquakes every $83{\pm}9years$ in the Central part of Chile, where it is located Santiago, the capital of Chile. The short interval between large earthquakes magnitude 8.5 has conditioned the Chilean seismic design practice to achieve almost operational performance level, despite the fact that the Chilean Code declares a scope of life safe performance level. Several Indexes have been widely used throughout the years in Chile to evaluate the structural characteristics of concrete buildings, with the intent to find a correlation between general structural conception and successful seismic performance. The Indexes presented are related only to global response of buildings under earthquake loads and not to the behavior or design of individual elements. A correlation between displacement demand and seismic structural damage is presented, using the index $H_o/T$ and the concrete compressive strain ${\varepsilon}_c$. Also the Chilean seismic design codes pre and post 2010 Maule earthquake are reviewed and the practice in seismic design vs Performance Based Design is presented. Performance Based Design procedures are not included in the Chilean seismic design code for buildings, nevertheless the earthquake experience has shown that the response of the Chilean buildings has been close to operational. This can be attributed to the fact that the drift of most engineered buildings designed in accordance with the Chilean practice falls below 0.5%. It is also known by experience that for frequent and even occasional earthquakes, buildings responded elastically and thus with "fully operational" performance. Taking the above into account, it can be said that, although the "basic objective" of the Chilean code is similar to the SEAOC VISION2000 criteria, the actual performance for normal buildings is closer to the "Essential/Hazardous objective".

방파제의 성능기반 내진설계법

김영준,박인준 한국지반공학회 2022 한국지반공학회논문집 Vol.38 No.12

The 1995 Kobe earthquake caused a massive damage to the Port of Kobe. Therefore, it was pointed out that it was impossible to design port structures for Level II (Mw 6.5) earthquakes with quasi-static analysis and Allowable Stress Design methods. In Japan and the United States, where earthquakes are frequent, the most advanced design standards for port facilities are introduced and applied, and the existing seismic design standards have been converted to performance-based design. Since 1999, the Korean Port Seismic Design Act has established a definition of necessary facilities and seismic grades through research on facilities that require seismic design and their seismic grades. It has also established a performance-based seismic design method based on experimental verification. In the performance-based seismic design method of the breakwater proposed in this study, the acceleration time history on the surface of the original ground was subjected to a fast Fourier transform, followed by a filter processing that corrected the frequency characteristics corresponding to the maximum allowable displacement with respect to performance level of the breakwater and the filtered spectrum. The horizontal seismic coefficient for the equivalent static analysis considering the displacement was calculated by inversely transforming (i.e., subjected to an inverse fast Fourier transform) into the acceleration time history and obtaining the maximum acceleration value. In addition, experiments and numerical analysis were performed to verify the performance-based seismic design method of breakwaters suitable for domestic earthquake levels.

Overview of Performance-Based Seismic Design of Building Structures in China

Li, Guo-Qiang,Xu, Yan-Bin,Sun, Fei-Fei Council on Tall Building and Urban Habitat Korea 2012 International journal of high-rise buildings Vol.1 No.3

The development history, the current situation and the future of the performance-based seismic design of building structures in China are presented in this paper. Firstly, the evolution of performance-based seismic design of building structures specified in the Chinese codes for seismic design of buildings of the edition 1974, 1978, 1989, 2001 and 2010 are introduced and compared. Secondly, in two parts, this paper details the provisions of performance-based seismic design in different Chinese codes. The first part is about the "Code for Seismic Design of Buildings" (GB50011) (edition 1989, 2001 and 2010) and "Technical Specification for Concrete Structures of Tall Building", which presents the concepts and methods of performance-based seismic design adopted in Chinese codes; The second part is about "Management Provisions for Seismic Design of Outof-codes High-rise Building Structures" and "Guidelines for Seismic Design of Out-of-codes High-rise Building Structures", which concludes the performance-based seismic design requirements for high-rise building structures over the relevant codes in China. Finally, according to those mentioned above, this paper pointed out the imperfections of current performance-based seismic design in China and proposed the possible direction for further improvement.

지반-구조물 상호작용 효과를 고려한 지진격리시스템이 적용된 원전 격납건물의 지진 취약도 평가

임승현,정형조,김민규,최인길 한국지진공학회 2013 한국지진공학회논문집 Vol.17 No.2

Several researches have been studied to enhance the seismic performance of nuclear power plants (NPPs) by application of seismic isolation. If a seismic base isolation system is applied to NPPs, seismic performance of nuclear power plants should be reevaluated considering the soil-structure interaction effect. The seismic fragility analysis method has been used as a quantitative seismic safety evaluation method for the NPP structures and equipment. In this study, the seismic performance of an isolated NPP is evaluated by seismic fragility curves considering the soil-structure interaction effect. The designed seismic isolation is introduced to a containment building of Shin-Kori NPP which is KSNP (Korean Standard Nuclear Power Plant), to improve its seismic performance. The seismic analysis is performed considering the soil-structure interaction effect by using the linearized model of seismic isolation with SASSI (System for Analysis of Soil-Structure Interaction) program. Finally, the seismic fragility is evaluated based on soil-isolation-structure interaction analysis results.

Seismic Performance Management of Aged Road Facilities in Korea: Part 1 – Fragility Curves

신수봉,김익현,송기일,박두희,김병민,안효준,홍기증 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.5

This study aimed to develop a decision-making support system for managing the seismic performance of aged road facilities in a road network, based on their evaluated seismic performance. This study was divided into two parts. In Part 1, seismic fragility functions are developed for bridges, tunnels, retaining walls, and slopes, while considering aging. In Part 2, the degradation of the seismic performance of the road network, along with social and economic resilience are evaluated based on these seismic fragility functions. The developed decision-making support system was applied to domestic test beds in Korea, and the results are discussed in Part 2. To develop seismic fragility, various ground motions suitable for the ground conditions in South Korea were generated. In particular, reduced- and real-size bridge piers and bearings were tested to study the effect of aging on seismic behavior. Other types of facilities, such as tunnels, retaining walls, and slopes, were also analyzed to study the same. For simplicity, representative facilities that can properly represent the seismic behavior of similar facilities were selected from a large number of facilities. The limit states for these representative facilities were defined, and their seismic fragility curves were calculated using these limit states.

Seismic fragility analysis of base isolation reinforced concrete structure building considering performance - a case study for Indonesia

Faiz Sulthan,Matsutaro Seki Techno-Press 2023 Structural monitoring and maintenance Vol.10 No.3

Indonesia has had seismic codes for earthquake-resistant structures designs since 1970 and has been updated five times to the latest in 2019. In updating the Indonesian seismic codes, seismic hazard maps for design also update, and there are changes to the Peak Ground Acceleration (PGA). Indonesian seismic design uses the concept of building performance levels consisting of Immediate occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Related to this performance level, cases still found that buildings were damaged more than their performance targets after the earthquake. Based on the above issues, this study aims to analyze the performance of base isolation design on existing target buildings and analyze the seismic fragility for a case study in Indonesia. The target building is a prototype design 8-story medium-rise residential building using the reinforced concrete moment frame structure. Seismic fragility analysis uses Incremental Dynamic Analysis (IDA) with Nonlinear Time History Analysis (NLTHA) and eleven selected ground motions based on soil classification, magnitude, fault distance, and earthquake source mechanism. The comparison result of IDA shows a trend of significant performance improvement, with the same performance level target and risk category, the base isolation structure can be used at 1.46-3.20 times higher PGA than the fixed base structure. Then the fragility analysis results show that the fixed base structure has a safety margin of 30% and a base isolation structure of 62.5% from the PGA design. This result is useful for assessing existing buildings or considering a new building's performance.