Sectional forces for seismic design of R/C frames by linear time history analysis and application to 3D single-story buildings

2011 ◽  
Vol 31 (3) ◽  
pp. 318-333 ◽  
Author(s):  
K.G. Kostinakis ◽  
A.M. Athanatopoulou ◽  
I.E. Avramidis
Author(s):  
Fatemeh Jalayer ◽  
Hossein Ebrahimian ◽  
Andrea Miano

AbstractThe Italian code requires spectrum compatibility with mean spectrum for a suite of accelerograms selected for time-history analysis. Although these requirements define minimum acceptability criteria, it is likely that code-based non-linear dynamic analysis is going to be done based on limited number of records. Performance-based safety-checking provides formal basis for addressing the record-to-record variability and the epistemic uncertainties due to limited number of records and in the estimation of the seismic hazard curve. “Cloud Analysis” is a non-linear time-history analysis procedure that employs the structural response to un-scaled ground motion records and can be directly implemented in performance-based safety-checking. This paper interprets the code-based provisions in a performance-based key and applies further restrictions to spectrum-compatible record selection aiming to implement Cloud Analysis. It is shown that, by multiplying a closed-form coefficient, code-based safety ratio could be transformed into simplified performance-based safety ratio. It is shown that, as a proof of concept, if the partial safety factors in the code are set to unity, this coefficient is going to be on average slightly larger than unity. The paper provides the basis for propagating the epistemic uncertainties due to limited sample size and in the seismic hazard curve to the performance-based safety ratio both in a rigorous and simplified manner. If epistemic uncertainties are considered, the average code-based safety checking could end up being unconservative with respect to performance-based procedures when the number of records is small. However, it is shown that performance-based safety checking is possible with no extra structural analyses.


Author(s):  
Iswandi Imran ◽  
Marie Hamidah ◽  
Tri Suryadi ◽  
Hasan Al-Harris ◽  
Syamsul Hidayat

<p>In order to overcome stringent seismic requirement in the new Greater Jakarta Light Rail Transit Project, a breakthrough seismic system shall be chosen to obtain expected structural performance. This seismic system shall be designed to provide operational performance level after strong earthquake events. To achieve the criteria, seismic isolation system using Lead Rubber Bearings is chosen. With this isolation system, Greater Jakarta LRT has become the first seismically isolated infrastructure and apparently an infrastructure with the largest numbers of LRBs in one single project in Indonesia. More than 10.400 Pcs LRBs are used for the first phase of the construction and the numbers will be certainly increased in the next phase of the construction. To evaluate the structural performance, non-linear time history analysis is used. A total of 3 pair matched ground motions will be used as the input for the response history analysis. The ability of the lead rubber bearing to isolate and dissipate earthquake actions will determine its structural performance level. This will be represented by the nonlinear hysteretic curves obtained throughout the earthquake actions.</p>


2009 ◽  
Vol 25 (3) ◽  
pp. 583-605 ◽  
Author(s):  
Wei Chiang Pang ◽  
David V. Rosowsky

This paper presents a direct displacement design (DDD) procedure that can be used for seismic design of multistory wood-framed structures. The proposed procedure is applicable to any pure shear deforming system. The design procedure is a promising design tool for performance-based seismic design since it allows consideration of multiple performance objectives (e.g., damage limitation, safety requirements) without requiring the engineer to perform a complex finite element or nonlinear time-history analysis of the complete structure. A simple procedure based on normalized modal analysis is used to convert the code-specified acceleration response spectrum into a set of interstory drift spectra. These spectra can be used to determine the minimum stiffness required for each floor based on the drift limit requirements. Specific shear walls can then be directly selected from a database of backbone curves. The procedure is illustrated on the design of two three-story ATC-63 archetype buildings, and the results are validated using nonlinear time-history analysis.


Author(s):  
K. J. Harshitha ◽  
R. Sunil ◽  
Avinash Gornale

Near fault earthquake record are rich in high frequencies that effects structures for far fault earthquake record lower frequencies is not effects highly in structure. The objective of the study is to be investigating the effect of near-fault and far fault earthquake motion on the response of RC moment resisting regular and irregular structure considering Near and Far situated fault zones. Linear time history analysis G+10 building has carried out for two structures. The effects of Near and Far faults zones were evaluated for G+10 Two structure the ordinary moment resisting frame system was considered for two building as a lateral load-resisting system. For two building time, history analysis was performed under two example earthquake motion Uattarkashi (Almora and Bhatwari) magnitude 6.8 Mw. The peak acceleration v/s time response spectra of the two horizontal components of the two records for Near source earthquake records @ a distance 21.7 km Bhatwari and Far source earthquake records @ a distance 153.5 km of Almora records are taken in virtual data centre of India earthquake records COSMOS Virtual Data Center - Strong Motion Center. For two building and earthquake record, the analysis was carried out for both conditions and compared with fixed base results for all analysis both Near-field and Far-field earthquake were considered. The mainly evaluated parameter were storey drift, storey displacement and storey force, period vibration results based on linear time history analysis considering two structures. The comparative study of four parameters considers the graphs and curves shows higher and lower values higher values show that the earthquake effect of building and damages is more.


2019 ◽  
Vol 10 (2) ◽  
pp. 166-184
Author(s):  
Johnny Setiawan ◽  
Iswandi Imran

Terdapat cukup banyak perubahan pada SNI 1726-2012, salah satunya adalah adanya persyaratanbatas geser dasar minimum (minimum base shear) yang tidak ada pada peraturan sebelumnya.Metode yang akan dilakukan adalah bangunan gedung dengan klasifikasi ketinggian rendah,sedang dan tinggi akan dianalisis dengan menerapkan geser dasar minimum dan tanpa geser dasarminimum. Analisis yang akan digunakan adalah analisis ragam spektrum respons (ResponsSpectrum Analysis, RSA), analisis respons riwayat waktu (Time History Analysis, THA) dananalisis respons riwayat waktu non linier (Non Linear Time History Analysis, NLTHA). Hasilanalisis menunjukkan bahwa pada peraturan SNI 1726-2012 dengan adanya persyaratan batasangeser dasar minimum dapat menjamin kinerja struktur sesuai dengan yang diharapkan.Kekhawatiran adanya batasan geser dasar minimum pada SNI 1726-2012 akan membuat desainmenjadi tidak ekonomis, ternyata tidak terbukti karena tidak memberikan pengaruh signifikanpada hasil desain, khususnya untuk bangunan dengan kategori ketinggian rendah dan sedang.Untuk bangunan dengan klasifikasi bangunan tinggi, analisis dan desain dengan memperhitungansyarat batasan geser dasar minimum dan tanpa memperhitungkan geser dasar minimum dapatmemberikan hasil desain yang baik, tetapi pengecekan pada Level Kinerja (Performance Level)sesuai dengan story drift menunjukkan bahwa analisis dengan memperhitungkan syarat geser dasarminimum memberikan hasil dengan level kinerja yang cukup baik yaitu Immediate Occupancy(IO) hingga Damage Control (DO), sedangkan tanpa memperhitungkan geser dasar minimummemberikan hasil dengan level kinerja yang kurang baik yaitu Life Safety (LS) hingga StructuralStability (SS). Sedangkan pada level kinerja elemen struktur, analisis tanpa memperhitungkangeser dasar minimum menyebabkan banyak elemen struktur yang berada pada level kinerjaCollapse Prevention (CP).


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