scholarly journals Minimization of Torsional Parameters in Dual Asymmetrical Building through Proper Configuration of Centres

2020 ◽  
Vol 8 (5) ◽  
pp. 5426-5433
Keyword(s):  
Linear Time ◽  
Angular Acceleration ◽  
Time History ◽  
Lateral Load ◽  
Early Research ◽  
The Core ◽  
Basic Model ◽  
Gravitational Loading ◽  
History Analysis ◽  
Irregular Buildings

Columns are the core lateral load resisting elements in the buildings which do not have any other forms of resisting components. The sectional dimensions of the columns are often judge based upon the gravitational loading or a combined effect of gravitational and lateral loading on the structure. As per the early research on irregular buildings, they are highly vulnerable for damage when subjected to lateral forces (seismic/wind) when compared to regular shaped buildings, due to the presence of torsional forces. It has also been proved that these torsional forces are generated due to structural eccentricities of the system. The centres of stiffness and strength are predominantly dependent upon the configuration of the lateral load resisting elements. In this study, the effect of proper configuration of column’s dimensions on torsional parameters of irregular buildings is carried out. Non-linear Time History analysis on Plan irregular building with dual asymmetry is performed using scaled acceleragrams and the torsional parameters such are diaphragm’s rotation, torsional irregularity ratio, angular acceleration of the diaphragm are compared with the basic model.

scholarly journals Record-to-record variability and code-compatible seismic safety-checking with limited number of records

2021 ◽  
Author(s):  
Fatemeh Jalayer ◽  
Hossein Ebrahimian ◽  
Andrea Miano
Keyword(s):  
Seismic Hazard ◽  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Safety ◽  
Hazard Curve ◽  
History Analysis ◽  
Non Linear ◽  
Seismic Hazard Curve ◽  
Cloud Analysis

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.

Enhancing the application potential of dissipative controlled rocking connections through detailing and design

2021 ◽  
Author(s):  
Brandon McHaffie ◽  
Peter Routledge ◽  
Alessandro Palermo
Keyword(s):  
Linear Time ◽  
Time History ◽  
Cost Effective ◽  
Real Structure ◽  
Construction Costs ◽  
Alternative Design ◽  
Design Philosophy ◽  
History Analysis ◽  
Application Potential ◽  
The University

<p>Research on low-damage systems has been significant in the past decade. These systems combine post- tensioning, which provides self-centring; and typically use replaceable devices, which give energy dissipation. WSP has used recent research, carried out at the University of Canterbury, on low-damage bridge piers and applied this into a real structure – the Wigram-Magdala Link Bridge. This is believed to be the first bridge in New Zealand and possibly worldwide to adopt such a system. Given this was the first application of the system to a real structure, there were some valuable learnings during design and construction. Firstly, the application of axial dissipaters has some limitations due to available material sizes, construction difficulty and aesthetics. Secondly, there is still some additional cost and complexity associated with using the low-damage system. Given these difficulties, this paper presents an alternative design philosophy which better captures the benefits of the low-damage system, which include cost-effective repair method, controlled damage and additional robustness and resilience. The alternative design philosophy presented is expected to result in reduced construction costs by reducing pier and foundation demands. Peak displacements and forces will be compared to the results from non-linear time history analysis to verify the performance of the low-damage connection using scaled ground motions. Furthermore, the paper will present the possible application of an alternative dissipation device, the lead extrusion damper, which can further improve the performance of low-damage connections.</p>

Seismic performance of Greater Jakarta LRT with added lead rubber bearing using non-linear time history analysis

2021 ◽  
Author(s):  
Iswandi Imran ◽  
Marie Hamidah ◽  
Tri Suryadi ◽  
Hasan Al-Harris ◽  
Syamsul Hidayat
Keyword(s):  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
Performance Level ◽  
Structural Performance ◽  
Isolation System ◽  
Rubber Bearing ◽  
Lead Rubber Bearing ◽  
History Analysis ◽  
Seismic System

<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>

scholarly journals Behaviour of RC Moment Resisting Regular and Irregular Framed Structures Situated Near and Far to Fault Zone

2020 ◽  
pp. 25-36
Author(s):  
K. J. Harshitha ◽  
R. Sunil ◽  
Avinash Gornale
Keyword(s):  
Linear Time ◽  
Time History ◽  
Time History Analysis ◽  
Near Fault ◽  
Earthquake Records ◽  
Earthquake Motion ◽  
History Analysis ◽  
Earthquake Record ◽  
Moment Resisting ◽  
Far Fault

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.

scholarly journals Evaluasi Geser Dasar Minimun pada SNI 1726-2012

2019 ◽  
Vol 10 (2) ◽  
pp. 166-184
Author(s):  
Johnny Setiawan ◽  
Iswandi Imran
Keyword(s):  
Linear Time ◽  
Damage Control ◽  
Time History ◽  
Time History Analysis ◽  
Performance Level ◽  
Life Safety ◽  
Base Shear ◽  
History Analysis ◽  
Story Drift ◽  
Immediate Occupancy

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).

Wind Loading and Wind Effects on the Roof of Harbin West Railway Station

2010 ◽  
Vol 163-167 ◽  
pp. 4280-4285
Author(s):  
Di Wu ◽  
Ying Sun ◽  
Yue Wu
Keyword(s):  
Wind Tunnel ◽  
Linear Time ◽  
Time History ◽  
Wind Load ◽  
Wind Pressure ◽  
Wind Loading ◽  
Induced Response ◽  
Railway Station ◽  
History Analysis ◽  
Fluctuating Wind

Taking Harbin west railway station as the researching object, the wind load distribution as well as its effects, which are widely used in practice, is investigated. First, wind pressure distribution on a rigid model is measured simultaneously in a wind tunnel. Some special characteristics of the measured wind pressure, especially its fluctuating component, are discussed. Then the fluctuating wind pressure field is reconstructed based on the synchronous multi-pressure scanning technique of wind tunnel tests and the proper orthogonal decomposition (POD) technique. The influence of lower RC structure on wind-induced vibration is investigated using non-linear time-history analysis. At last, a new method is introduced to obtain equivalent static wind load (ESWL) that reproduce all largest load effects at the same time. With the synthetic application of above methods, the problems such as: complex time and spatial distribution of fluctuating wind; multi-mode vibration of wind-induced response; multiple equivalent objectives for ESWL, can be solved efficiently.

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