scholarly journals SEISMIC EVALUATION OF REINFORCED CONCRETE BUILDING USING NON-LINEAR TIME HISTORY ANALYSIS

2021 ◽  
Vol 9 (07) ◽  
pp. 454-483
Author(s):  
Yilachew Getachew ◽  
◽  
Liu Yianhui ◽  
Tseganesh Abegaz ◽  
◽  
...  
Keyword(s):  
Linear Time ◽  
Focal Point ◽  
Addis Ababa ◽  
Time History ◽  
City Government ◽  
Seismic Evaluation ◽  
Ground Shaking ◽  
Speed Increase ◽  
Time Space ◽  
Inelastic Reaction

Thestructure exposed to earthquake is required to show inelastic conduct that the misshaping in a part doesnt stay corresponding to the inside power. A non-direct investigation represents the inelastic reaction. Both material non-linearity and mathematical nonlinearity cases are considered. There is plastic distortion and energy assimilation in a part for more significant levels of interior power. This sort of nonlinear conduct is alluded to as material non-linearity. A few diverse hysteresis models are accessible to depict the conduct of various kinds of materials. Generally, these vary in the measure of energy they disperse in a given pattern of distortion, and how the energy dissemination conduct changes with an expanding measure of disfigurement. Turn hysteresis model is utilized. This study work utilizes fifteen-story and two cellars working of 40/60 undertaking of City Government of Addis Ababa Saving House Enterprise as a contextual investigation. A correlation is made between straight versatile examination and non-direct time history as far as story Displacement, Inter-story float, story Shear, Axial power, and Torsion. Along these lines, it ought not to be astonishing that structures endure harm during extraordinary ground shaking. The principal focal point of this work is to assess the seismic obstruction by utilizing non-direct time history investigation with the goal that the harm will be controlled satisfactorily. Seismic contribution to nonlinear unique examinations of constructions is normally characterized as far as speed increase time arrangement. Three references Earthquake Ankober 2016, EL-Centro 1940, and Sierra-Madre 1991 are utilized to create counterfeit time history utilizing time-space strategy. The time-space strategy is by and large viewed as a superior methodology for ghostly coordinating since this technique changes the speed increase time narratives in the time area by adding wavelets.

Adaptive Spectra-Based Pushover Procedure for Seismic Evaluation of Structures

2000 ◽  
Vol 16 (2) ◽  
pp. 367-391 ◽  
Author(s):  
Balram Gupta ◽  
Sashi K. Kunnath
Keyword(s):  
Response Spectrum ◽  
Pushover Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Time History ◽  
Northridge Earthquake ◽  
Seismic Evaluation ◽  
Seismic Demands ◽  
Ground Shaking ◽  
Motion Characteristics ◽  
Nonlinear Time History

The estimation of inelastic seismic demands using nonlinear static procedures, or pushover analyses, are inevitably going to be favored by practicing engineers over nonlinear time-history methods. While there has been some concern over the reliability of static procedures to predict inelastic seismic demands, improved procedures overcoming these drawbacks are still forthcoming. In this paper, the potential limitations of static procedures, such as those recommended in FEMA 273, are highlighted through an evaluation of the response of instrumented buildings that experienced strong ground shaking in the 1994 Northridge earthquake. A new enhanced adaptive “modal” site-specific spectra-based pushover analysis is proposed, which accounts for the effect of higher modes and overcomes the shortcomings of the FEMA procedure. Features of the proposed procedure include its similarity to traditional response spectrum-based analysis and the explicit consideration of ground motion characteristics during the analysis. It is demonstrated that the proposed procedure is able to reasonably capture important response attributes, such as interstory drift and failure mechanisms, even for structures with discontinuities in strength and/or stiffness that only a detailed nonlinear dynamic analysis could predict.

scholarly journals Comparison of analysis techniques for the seismic evaluation of an 88-storey concrete building

2021 ◽  
Author(s):  
Andrew Shaffu
Keyword(s):  
Linear Time ◽  
Time History ◽  
Seismic Zone ◽  
Seismic Evaluation ◽  
Coupling Beams ◽  
Orthogonal Direction ◽  
History Analysis ◽  
Nonlinear Time History Analyses ◽  
Concrete Building ◽  
Nonlinear Time History

This thesis presents the comparison of results for an 88-storey reinforced concrete building subjected to static and dynamic analyses. Similar to a building designed in a moderate seismic zone, the structure is designed and detailed according to the ACI 318M (2002) Code provisions and the seismic provisions of the UBC (1997). The building is modeled according to structural drawings and element design specifications are used in describing members' deformation characteristics. Resistance to dynamic motion is provided through boxed core-wall assemblies acting as cantilevers walls in one direction and linked with coupling beams at storey levels in the orthogonal direction. The equivalent static, dynamic modal spectrum, linear time-history and nonlinear time-history analyses are employed and a comparison of maximum inter-storey drift response is provided. The results of the analyses show that the linear time-history analysis is the most appropriate method in capturing the behavior of this particular building under dynamic loading.

Performance of Structures with Passive Energy Dissipators

2002 ◽  
Vol 18 (1) ◽  
pp. 105-119 ◽  
Author(s):  
H. Kit Miyamoto ◽  
J. P. Singh
Keyword(s):  
High Intensity ◽  
Linear Time ◽  
Response Spectrum ◽  
Time History ◽  
Seismic Intensity ◽  
Ground Shaking ◽  
Blue Book ◽  
Earthquake Performance ◽  
Energy Dissipators ◽  
Nonlinear Time History

The purpose of this paper is to evaluate the earthquake performance of structures with passive energy dissipators. This paper addresses the following issues: (1) evaluation of seismic intensity levels at which frames incorporating the energy dissipating system (EDS) remain elastic; (2) performance evaluation of frames incorporating an EDS for high-intensity ground shaking; and (3) evaluation of SEAOC Blue Book provisions. Linear time-history analyses indicate that frames with an EDS generally remain elastic during earthquake events that do not greatly exceed the UBC Zone 4 response spectrum. Nonlinear time-history analyses indicate the following: (1) the frames with an EDS can provide “immediate occupancy performance” for high-intensity earthquakes; (2) the performance level of the frames with an EDS exceeds that of frames without an EDS; and (3) the performance of the frame with an EDS, which was designed per Blue Book provisions, can exceed life safety performance.

scholarly journals Seismic Vulnerability Assessment of Portuguese Adobe Buildings

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 200
Author(s):  
Samar Momin ◽  
Holger Lovon ◽  
Vitor Silva ◽  
Tiago Miguel Ferreira ◽  
Romeu Vicente
Keyword(s):  
Structural Damage ◽  
Seismic Vulnerability ◽  
Linear Time ◽  
Time History ◽  
Building Stock ◽  
Seismic Vulnerability Assessment ◽  
Ground Shaking ◽  
Brittle Behavior ◽  
Historical Significance ◽  
Ground Motion Records

Adobe construction represents 5.3% of the total Portuguese building stock according to the latest National Housing Census. The distribution of these adobe buildings is scattered across the country, with higher density in the central region and in Algarve in the south, where the seismic hazard is highest. A large proportion of these buildings are still in use for residential and commercial purposes and are of historical significance, contributing to the cultural heritage of the country. Adobe buildings are known to exhibit low seismic resistance due to their brittle behavior, thus making them vulnerable to ground shaking and more prone to structural damage that can potentially cause human fatalities. Three buildings with one-story, two-stories, and two-stories plus an attic were numerically modeled using solid and contact elements. Calibration and validation of material properties were carried out following experimental results. A set of 30 ground motion records with bi-directional components were selected, and non-linear time-history analyses were performed until complete collapse occurred. Two novel engineering demand parameters (EDPs) were used, and damage thresholds were proposed. Finally, fragility and fatality vulnerability functions were derived. These functions can be used directly in seismic risk assessment studies.

scholarly journals Comparison of analysis techniques for the seismic evaluation of an 88-storey concrete building

2021 ◽  
Author(s):  
Andrew Shaffu
Keyword(s):  
Linear Time ◽  
Time History ◽  
Seismic Zone ◽  
Seismic Evaluation ◽  
Coupling Beams ◽  
Orthogonal Direction ◽  
History Analysis ◽  
Nonlinear Time History Analyses ◽  
Concrete Building ◽  
Nonlinear Time History

This thesis presents the comparison of results for an 88-storey reinforced concrete building subjected to static and dynamic analyses. Similar to a building designed in a moderate seismic zone, the structure is designed and detailed according to the ACI 318M (2002) Code provisions and the seismic provisions of the UBC (1997). The building is modeled according to structural drawings and element design specifications are used in describing members' deformation characteristics. Resistance to dynamic motion is provided through boxed core-wall assemblies acting as cantilevers walls in one direction and linked with coupling beams at storey levels in the orthogonal direction. The equivalent static, dynamic modal spectrum, linear time-history and nonlinear time-history analyses are employed and a comparison of maximum inter-storey drift response is provided. The results of the analyses show that the linear time-history analysis is the most appropriate method in capturing the behavior of this particular building under dynamic loading.

Comparison of Interstorey Drift in General RC Buildings in Pounding and No Pounding Case

2020 ◽  
Vol 2 (1) ◽  
pp. 40-47
Author(s):  
Anand Dev Bhatt
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Case Analysis ◽  
Rc Buildings ◽  
Adjacent Buildings ◽  
Sufficient Distance ◽  
Earthquake Load ◽  
Interstorey Drift ◽  
Lower Height

 Inter-storey drift is an important parameter of structural behavior in seismic analysis of buildings. Pounding effect in building simply means collision between adjacent buildings due to earthquake load caused by out of phase vibration of adjacent buildings. There is variation in inter-storey drift of adjacent buildings during pounding case and no pounding case. The main objective of this research was to compare the inter-storey drift of general adjacent RC buildings in pounding and no pounding case. For this study two adjacent RC buildings having same number of stories have been considered. For pounding case analysis there is no gap in between adjacent buildings and for no pounding case analysis there is sufficient distance between adjacent buildings. The model consists of adjacent buildings having 4 and 4 stories but unequal storey height. Both the buildings have same material & sectional properties. Fast non-linear time history analysis was performed by using El-centro earthquake data as ground motion. Adjacent buildings having different overall height were modelled in SAP 2000 v 15 using gap element for pounding case. Finally, analysis was done and inter-storey drift was compared. It was found that in higher building inter-storey drift is greater in no pounding case than in pounding case but in adjacent lower height building the result was reversed. Additionally, it was found that in general residential RC buildings maximum inter-storey drift occurs in 2nd floor.

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.

scholarly journals Tuned Mass Damper Design for Slender Masonry Structures: A Framework for Linear and Nonlinear Analysis

2021 ◽  
Vol 11 (8) ◽  
pp. 3425
Author(s):  
Marco Zucca ◽  
Nicola Longarini ◽  
Marco Simoncelli ◽  
Aly Mousaad Aly
Keyword(s):  
Nonlinear Analysis ◽  
Linear Time ◽  
Design Procedure ◽  
Time History ◽  
Tuned Mass Damper ◽  
Second Phase ◽  
Masonry Structures ◽  
Base Shear ◽  
Mass Damper ◽  
Linear And Nonlinear

The paper presents a proposed framework to optimize the tuned mass damper (TMD) design, useful for seismic improvement of slender masonry structures. A historical masonry chimney located in northern Italy was considered to illustrate the proposed TMD design procedure and to evaluate the seismic performance of the system. The optimization process was subdivided into two fundamental phases. In the first phase, the main TMD parameters were defined starting from the dynamic behavior of the chimney by finite element modeling (FEM). A series of linear time-history analyses were carried out to point out the structural improvements in terms of top displacement, base shear, and bending moment. In the second phase, masonry's nonlinear behavior was considered, and a fiber model of the chimney was implemented. Pushover analyses were performed to obtain the capacity curve of the structure and to evaluate the performance of the TMD. The results of the linear and nonlinear analysis reveal the effectiveness of the proposed TMD design procedure for slender masonry structures.

scholarly journals Displacement-based design of precast hinged portal frames with additional dissipating devices at beam-to-column joints

2021 ◽  
Author(s):  
Andrea Belleri ◽  
Simone Labò
Keyword(s):  
Design Methodology ◽  
Linear Time ◽  
Design Procedure ◽  
Time History ◽  
Structural System ◽  
Additional Degree ◽  
Speed Up ◽  
Column Joint ◽  
Displacement Based ◽  
Mechanical Devices

AbstractThe seismic performance of precast portal frames typical of the industrial and commercial sector could be generally improved by providing additional mechanical devices at the beam-to-column joint. Such devices could provide an additional degree of fixity and energy dissipation in a joint generally characterized by a dry hinged connection, adopted to speed-up the construction phase. Another advantage of placing additional devices at the beam-to-column joint is the possibility to act as a fuse, concentrating the seismic damage on few sacrificial and replaceable elements. A procedure to design precast portal frames adopting additional devices is provided herein. The procedure moves from the Displacement-Based Design methodology proposed by M.J.N. Priestley, and it is applicable for both the design of new structures and the retrofit of existing ones. After the derivation of the required analytical formulations, the procedure is applied to select the additional devices for a new and an existing structural system. The validation through non-linear time history analyses allows to highlight the advantages and drawbacks of the considered devices and to prove the effectiveness of the proposed design procedure.

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>

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