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.

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.

scholarly journals Deterministic Wind Load Dynamic Analysis of High Rise Steel Buildings Including P-Delta Effects

2019 ◽  
Vol 26 (1) ◽  
pp. 129-135
Author(s):  
Rafaa M. Abbas ◽  
Ahmed Sada Dheeb
Keyword(s):  
Time History ◽  
Wind Load ◽  
Steel Buildings ◽  
High Rise ◽  
Building Models ◽  
History Analysis ◽  
Nonlinear Time History Analyses ◽  
Steel Building ◽  
Linear And Nonlinear ◽  
Nonlinear Time History

This study concerns with the investigation of the second-order geometric nonlinearity effects of P-Delta analysis on the dynamic response of high rise steel buildings due to deterministic wind load. Linear and nonlinear time history analyses were conducted to analyze different tall steel building models adopted in the study. Five steel building models ranging from 10 to 50 stories were numerically modeled and analyzed using finite element code ETABS (version 16.0.3). Deterministic dynamic wind load per ASCE 7-10 is applied to the buildings as a main lateral load. Comparative study between linear and nonlinear time history analyses reveals that nonlinear time history analysis including P-Delta effects displayed larger values of buildings lateral sway than those of linear time history analysis. Generally, including P-Delta effect in the nonlinear analysis increases the flexibility of the building structure, and thus increases response peak values and that peak values occur at a longer time periods indicating lesser response oscillations. The study recommends that P-Delta effect need to be addressed by any dynamic wind analysis for tall steel buildings with 20 story height or more.

scholarly journals Intensity Measure Based on a Smooth Inelastic Peak Period for a More Effective Incremental Dynamic Analysis

2020 ◽  
Vol 10 (23) ◽  
pp. 8632
Author(s):  
Juan Carlos Vielma ◽  
Maria Cristina Porcu ◽  
Nelson López
Keyword(s):  
Dynamic Analysis ◽  
Fourier Spectrum ◽  
Linear Time ◽  
Time History ◽  
Incremental Dynamic Analysis ◽  
Seismic Intensity ◽  
Intensity Measure ◽  
Peak Period ◽  
History Analysis ◽  
Concrete Building

The Incremental Dynamic Analysis (IDA) assesses the global collapse capacity of a structure by plotting its maximum inelastic response, obtained through a non-linear time-history analysis, versus the scaled intensity of different input earthquakes. The seismic intensity is often measured through the spectral acceleration at the fundamental elastic period. However, this can produce highly variable results. An alternative method is presented in this paper that relies on the elongated period, calculated either from the Fourier spectrum of the acceleration at a target building point (inelastic peak period) or from a smooth Fourier spectrum (inelastic smooth peak period). By referring to a reference reinforced concrete building and to a set of 10 spectrum-consistent earthquakes, the paper presents the results of a wide investigation. First, the variation in the elongated period as a function of the seismic intensity is discussed. Then, the effectiveness of the proposed method is assessed by comparing the IDA curves to those obtained through the elastic period or through approximate values of the elongated period given in the literature. The results show that the alternative IDA procedure generates curves with less-dispersed collapse thresholds. A statistical analysis shows significant improvements in the results when the inelastic smooth peak period is adopted.

scholarly journals Comparison of Novel Seismic Protection Devices to Attenuate the Earthquake Induced Energy

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 73
Author(s):  
Osman Hansu ◽  
Esra Mete Güneyisi
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Protection ◽  
Base Shear ◽  
Seismic Demands ◽  
Nonlinear Time History Analyses ◽  
History Of ◽  
Protection Devices ◽  
Nonlinear Time History ◽  
Better Than

This study addresses an alternative use of viscous dampers (VDs) associated with buckling restrained braces (BRBs) as innovative seismic protection devices. For this purpose, 4-, 8- and 12-story steel bare frames were designed with 6.5 m equal span length and 4 m story height. Thereafter, they were seismically improved by mounting the VDs and BRBs in three patterns, namely outer bays, inner bays, and all bays over the frame heights. The structures were modeled using SAP 2000 software and evaluated by the nonlinear time history analyses subjected to the six natural ground motions. The seismic responses of the structures were investigated for the lateral displacement, interstory drift, absolute acceleration, maximum base shear, and time history of roof displacement. The results clearly indicated that the VDs and BRBs reduced seismic demands significantly compared to the bare frame. Moreover, the all-bay pattern performed better than the others.

scholarly journals Seismic Performance of a Green Roof Structure

2021 ◽  
Vol 13 (8) ◽  
pp. 4278
Author(s):  
Svetlana Tam ◽  
Jenna Wong
Keyword(s):  
Green Roof ◽  
Time History ◽  
Green Roofs ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Roof Structure ◽  
Nonlinear Time History Analyses ◽  
Vegetated Roofs ◽  
Nonlinear Time History ◽  
The Impact

Sustainability addresses the need to reduce the structure’s impact on the environment but does not reduce the environment’s impact on the structure. To explore this relationship, this study focuses on quantifying the impact of green roofs or vegetated roofs on seismic responses such as story displacements, interstory drifts, and floor level accelerations. Using an archetype three-story steel moment frame, nonlinear time history analyses are conducted in OpenSees for a shallow and deep green roof using a suite of ground motions from various distances from the fault to identify key trends and sensitivities in response.

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 Performance of an Existing Reinforced Concrete Building Designed in Accordance to Older Indonesian Seismic Code: A Case Study for a Hotel in Kupang, Indonesia

2018 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Pamuda Pudjisuryadi ◽  
Benjamin Lumantarna ◽  
Ryan Setiawan ◽  
Christian Handoko
Keyword(s):  
Plastic Hinge ◽  
Time History ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Ground Acceleration ◽  
Seismic Code ◽  
Damage Level ◽  
History Analysis ◽  
Nonlinear Time History ◽  
Seismic Hazard Map

The recent seismic code SNI 1726-2012 is significantly different compared to the older code SNI 1726-2002. The seismic hazard map was significantly changed and the level of maximum considered earthquake was significantly increased. Therefore, buildings designed according to outdated code may not resist the higher demand required by newer code. In this study, seismic performance of Hotel X in Kupang, Indonesia which was designed based on SNI-1726-2002 is investigated. The structure was analyzed using Nonlinear Time History Analysis. The seismic load used was a spectrum consistent ground acceleration generated from El-Centro 18 May 1940 North-South component in accordance to SNI 1726-2012. The results show that Hotel X can resist maximum considered earthquake required by SNI 1726-2012. The maximum drift ratio is 0.81% which is lower than the limit set by FEMA 356-2000 (2%). Plastic hinge damage level is also lower than the allowance in ACMC 2001.

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