Performance-based Analysis of Code-base Designed Structures in the Philippines

Rubio. Christabel Jane P,Tabong. Kristoffer Dave A.,Lucio. Mark Elson C.,Jeong. Sangman 한국방재학회 2017 한국방재학회논문집 Vol.17 No.3

본 연구에서는 비선형등가정적해석법(nonlinear static pushover analysis)을 사용하여 지진 발생시 예측 가능한 성능 요건을 충족시키는 코드 기반 설계 구조의 기능을 조사하였다. 이는 SAP2000을 사용하여 Makati Science High School (MSHS)건물의 골조 구조를 개발함으로써 수행되었다. 이후, Applied Technology Council (ATC)에서 제공된 콘크리트 건물의 내진평가 및 보강에 대한 코드인 ATC-40 조항에 따라 비선형등가정적해석법이 수행되었다. 이 분석을 통해 pushover curve를 얻었으며, 이 그래프는 모든 분석단계에서 구조물의 변위에 따른 소성힌지의 위치 및 상태를 나타낸 것이다. 필리핀의 대부분 학교건물은 일반적으로 대피소로 사용되기 때문에 Immediate Occupancy(IO)성능기준을 만족하기 위해 ATC-40에서 제공된 허용 기준과 pushover curve를 비교하였다. 비교결과 분석을 통해, MSHS 건물은 지진발생시 비상대피소로의 기능을 수행할 수 있는 것으로 평가되었다. 본 연구는 코드기반으로 설계된 건물의 변수와 IO 성능기준의 관계를 이해하는데 기여할 수 있다. 또한, 비선형등가정 적해석절차를 이용하여 지진발생시 MSHS 건물에 미치는 손상 결과를 예측할 수 있다. The ability of code-base designed structures to meet predictable performance requirement in an event of an earthquake was investigated in this study using nonlinear static pushover analysis. This was performed by developing the structural framework of Manila Science High School (MSHS) building using SAP2000. Subsequently, a nonlinear static pushover analysis according to the provisions of ATC-40, a code provided by the Applied Technology Council (ATC) on Seismic Evaluation and Retrofit of Concrete Buildings was performed. The analysis generated a pushover curve, a graph that displays the total drift of the structure versus base shear and the possible location and condition of the plastic hinges at every step of the analysis. Results were compared with the acceptable criteria provided by ATC-40 for Immediate Occupancy (IO) performance level since most school buildings in the Philippines are commonly used as evacuation centers. By analyzing the results, it was found out that the MSHS building will behave at Immediate Occupancy after an earthquake event. This study can contribute in verifying if the parameters used in code-base designed structures satisfy the requirements for IO performance level. Also, this study can estimate the possible post-earthquake damage effects on the MSHS building by using the nonlinear static analysis procedure.

Assessment of FEMA356 nonlinear static procedure and modal pushover analysis for seismic evaluation of buildings

Hamid Reza Khoshnoud,Kadir Marsono 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.2

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP,FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

Assessment of FEMA356 nonlinear static procedure and modal pushover analysis for seismic evaluation of buildings

Khoshnoud, Hamid Reza,Marsono, Kadir Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.2

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP, FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

지진응답평가를 위한 비선형 약산법의 오차해석

박진화,강병두,노필성,김재웅 동아대학교 환경문제연구소 2003 硏究報告 Vol.25 No.2

Recently, a variety of methods are proposed to solve the problems shown in a existing performance-based design of structure. The most accurate one among analysis methods for the performance evaluation of structure is nonlinear time history analysis. However, the approximate analysis methods in aspect of practicality and simplicity are needed. Even though there are linear capacity spectrum method and nonlinear capacity spectrum method through nonlinear static analysis as the representative approximate methods, a repetitive calculation process is consumed and the result is also likely to be inaccurate. Therefore, this research presents nonlinear direct spectrum method which directly enables nonlinear maximum response to derive, after obtaining the yielding strength and the frequency of structure from pushover curves, without going through a series of calculation processes. Also, it is proposed to compare and examine the accuracy and practicality through an example structure.

An evaluation of the seismic response of symmetric steel space buildings

Burak Yön 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.2

This paper evaluates the seismic response of three dimensional steel space buildings using the spread plastic hinge approach. A numerical study was carried out in which a sample steel space building was selected for pushover analysis and incremental nonlinear dynamic time history analysis. For the nonlinear analysis, three earthquake acceleration records were selected to ensure compatibility with the design spectrum defined in the Turkish Earthquake Code. The interstorey drift, capacity curve, maximum responses and dynamic pushover curves of the building were obtained. The analysis results were compared and good correlation was obtained between the idealized dynamic analyses envelopes with and static pushover curves for the selected building. As a result to more accurately account response of steel buildings, dynamic pushover envelopes can be obtained and compared with static pushover curve of the building.

비보강 조적조 건축물의 외부 보강에 따른 내진성능 연구

김종연,강종 한국구조물진단유지관리공학회 2024 한국구조물진단유지관리공학회 논문집 Vol.28 No.2

내진설계 되지 아니한 조적조 건축물의 내진성능을 평가하고 건축물의 외부에 내진 보강 공법을 채택하여 내진성능을 향상시키고자 하였다. 내진성능을 평가하기 위해 건축물 내진설계 기준 및 해설(KDS 41 17 00 : 2019)과 기존 시설물(건축물) 내진성능 평가요령을 적용하였으며 비선형 정적해석으로 pushover해석을 수행하였다. 해석결과, 우리나라 주택의 내진설계 보급 비율이 낮고 주택의 많은 비중을 차지하고 있는 것이 조적조 건축물임을 고려하면 내진보강이 시급한 것으로 판단되었다. 조적조 건축물에 철골 보-기등+가새 프레임을 보강할 경우 층간 변형각은 X방향 0.043%이며 Y방향 0.047%로 나타나 규정을 만족하였다. 성능 수준별 중력하중저항능력은 X, Y방향 모두 거주가능으로 판정되어 안전한 것으로 판단되었다. 건축물의 외부에 보강함으로써 주택의 거주성과 편의성을 확보하면서 공사가 가능할 것으로 보여지며 지진성능과 구조물의 거동을 보다 명확하게 예측할 수 있을 것으로 사료 되었다. In this study, we evaluated the seismic performance of a masonry building that was not designed to be earthquake-resistant and attempted to improve the seismic performance by adopting a seismic reinforcement method on the exterior of the building. In addition, the building seismic design standards and commentary(KDS 41 17 00:2019) and existing facility(building) seismic performance evaluation methods were applied to evaluate seismic performance, and a pushover analysis was performed using non-linear static analysis. As the result of this study, it was determined that seismic reinforcement was urgent because the distribution rate of earthquake-resistant design of houses in Korea was low and masonry structures accounted for a large proportion of houses. When reinforcing the steel beam-column+brace frame in a masonry building, the story drift angle was 0.043% in the X direction and 0.047% in the Y direction, indicating that it satisfied the regulations. The gravity load resistance capacity by performance level was judged to be a safe building because it was habitable in both X and Y directions. In conclusion, it is believed that the livability and convenience of the house can be secured by reinforcing the exterior of the building and the seismic performance and behavior of the structure can be clearly predicted.

고차모드의 영향을 고려한 비선형 직접스펙트럼법

박진화,강병두,노필성,김재웅 동아대학교 건설기술연구소 2002 硏究報告 Vol.26 No.1

Recently, a variety of methods are proposed to solve the problems shown in a existing performance-based design of structure. Among those methods, capacity spectrum method(ATC-40, FEMA-273) is one of general methods. The basis of the capacity spectrum method is the idea that the peak response of an inelastic system can be estimated as the peak response of a linear elastic system(equivalent single degree of freedom) with reduced stiffness and increased damping. However, the capacity spectrum method with equivalent SDOF systems characterizing the nonlinear response of multistory structures frequently makes iterative calculations and inaccurate results; and may potentially mislead if higher modes play a significant role in the response. Accordingly, in this study, nonlinear direct spectrum method is proposed and examined as one of methods considering the influence of higher modes to improve accuracy of analysis.

내진성능평가를 위한 다자유도 교량의 수정 비선형 등가정적해석법

조창근,김영상,배수호 한국구조물진단유지관리공학회 2006 한국구조물진단유지관리공학회 논문집 Vol.10 No.4

다자유도의 교량에 횡방향 지진하중을 받는 경우, 교량의 내진성능설계 및 성능평가를 위한 두 가지 비선형 등가 정적해석절차를 제시하였다. 빌딩구조물에 대한 FEMA-273의 변위계수법과 ATC에서 채택하고 있는 역량스펙트럼법을 개선하여 다자유도 연속교량의 내진성능평가에 적용토록 제시하였다. 수정된 두 방법들에 대한 적합성을 시간이력 동적해석과 비교토록 하였다. 다자유도 교량의 교축직각방향 관성력 분포를 합리적으로 반영하기 위하여, 수평방향 지진하중의 분포형태에 따른 모드 및 스펙트럴 하중분포를 적용토록 하였다. 철근 콘크리트 교각 부재는 하중-기초법에 의한 비선형 층상화 골조 유한요소 모델을 사용하여 교량 구조물을 모델링 하였다. Two methods of the nonlinear static pushover analysis have been presented for the performance-based seismic design and evaluation of MDOF continuous bridges. Guidelines for buildings presented in FEMA-273 applying the Displacement Coefficient Method (DCM) and in ATC applying the Capacity Spectrum Method(CSM) have been modified for MDOF bridges. Two methods are compared with the time- history analysis. The lateral load distribution pattern for seismic loads has been examined in the static pushover analysis. The force-based fiber frame finite element has been implemented in the modeling of reinforced concrete piers.

Error Estimation of Nonlinear Equivalent Static Analysis for 3D-BRB Frames

Hosein Sangtarash,Mohammad-Reza Banan,Mahmoud-Reza Banan 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.5

Capacity Spectrum Method (CSM) as a nonlinear equivalent static method is one of the practical procedures which is usually usedto estimate the seismic demands for design and evaluation of structural systems. This paper proposes a nonlinear equivalent staticmethod called MPA-MCSM which combines the Modified Capacity Spectrum Method, MCSM, and the Modal Pushover Analysis,MPA. The accuracy of the developed algorithm is investigated for response prediction of Buckling Restrained Brace (BRB) frameswith irregularities in elevation. The accuracy assessment of the proposed method is evaluated based on the computation of fourseismic demands; peak roof displacement, story drift, base shear and story shear for each considered structure. The accuracy of MPAMCSMresponses is checked against the results obtained from nonlinear time-history analysis. Thirty different models consist of 3-,9- and 20-story structures subjected to 7 pairs of ground motions were analyzed. The results reveal that MPA-MCSM providesconservative seismic demands and has a good accuracy for BRB frames.

Experiments on reinforced concrete beam-column joints under cyclic loads and evaluating their response by nonlinear static pushover analysis

Sharma, Akanshu,Reddy, G.R.,Eligehausen, Rolf,Vaze, K.K.,Ghosh, A.K.,Kushwaha, H.S. Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.1

Beam-column joints are the key structural elements, which dictate the behavior of structures subjected to earthquake loading. Though large experimental work has been conducted in the past, still various issues regarding the post-yield behavior, ductility and failure modes of the joints make it a highly important research topic. This paper presents experimental results obtained for eight beam-column joints of different sizes and configuration under cyclic loads along with the analytical evaluation of their response using a simple and effective analytical procedure based on nonlinear static pushover analysis. It is shown that even the simplified analysis can predict, to a good extent, the behavior of the joints by giving the important information on both strength and ductility of the joints and can even be used for prediction of failure modes. The results for four interior and four exterior joints are presented. One confined and one unconfined joint for each configuration were tested and analyzed. The experimental and analytical results are presented in the form of load-deflection. Analytical plots are compared with envelope of experimentally obtained hysteretic loops for the joints. The behavior of various joints under cyclic loads is carefully examined and presented. It is also shown that the procedure described can be effectively utilized to analytically gather the information on behavior of joints.