scholarly journals Seismic fragility analysis of pre-1975 conventional concrete frame buildings in Canada

2018 ◽  
Vol 45 (9) ◽  
pp. 728-738 ◽  
Author(s):  
Abdullah Al Mamun ◽  
Murat Saatcioglu
Keyword(s):  
Dynamic Analysis ◽  
Seismic Vulnerability ◽  
Time History ◽  
Incremental Dynamic Analysis ◽  
Assessment Tools ◽  
Fragility Analysis ◽  
Reinforced Concrete Frame ◽  
Earthquake Intensity ◽  
Concrete Frame ◽  
Frame Buildings

Fragility analysis was conducted for reinforced concrete frame buildings in Canada designed based on the 1965 National Building Code of Canada as representative of pre-1975 era of seismic design practice. Two-, five-, and ten-storey buildings were designed for Vancouver and Ottawa, representing buildings in high and medium seismic regions. They were modelled for inelastic response time history analysis, with respective inelastic hysteretic models for flexure and shear. Software PERFORM-3D was used to conduct incremental dynamic analysis under incrementally increasing earthquake intensity. Probabilistic analysis of the results of incremental dynamic analysis led to the development of fragility functions, which can be used as seismic vulnerability assessment tools. The results are compared with those generated for frame buildings designed on the basis of the 2010 NBCC. The comparison indicates that the probabilities of exceeding performance levels are significantly higher for older buildings relative to recently built fully ductile and moderately ductile buildings, respectively.

Quantifying the Reduction in Collapse Safety of Main Shock–Damaged Reinforced Concrete Frames with Infills

2017 ◽  
Vol 33 (1) ◽  
pp. 25-44 ◽  
Author(s):  
Henry V. Burton ◽  
Mayank Sharma
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Analysis ◽  
Main Shock ◽  
Limit State ◽  
Incremental Dynamic Analysis ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Frame Buildings ◽  
Story Drift

A performance-based methodology is presented to quantify the reduction in collapse safety of main shock–damaged reinforced concrete frame buildings with infills. After assessing their collapse safety in the intact state, the residual collapse capacity following main shock damage is evaluated by conducting incremental dynamic analysis to collapse using main shock–aftershock ground motion sequences. The median collapse capacity and conditional probability of collapse for the main shock–damaged building, normalized by that of the intact case are the metrics used to measure the reduction in collapse safety. Taller buildings with built-in soft and weak first stories have the highest reduction in collapse safety as a result of main shock damage. Among the engineering demand parameters recorded during the main shock analyses, story drift demands (peak transient and residual) and infill strut axial deformations have the highest correlation with the decline in collapse performance. The results of the main shock–aftershock incremental dynamic analysis to collapse are used to develop fragility functions for the limit state defined by the building being structurally unsafe to occupy.

scholarly journals Assessment of Seismic Vulnerability of Reinforced Concrete Frame buildings

2018 ◽  
Vol 149 ◽  
pp. 02036
Author(s):  
Cherifi Fatiha ◽  
Farsi Mohammed ◽  
Kaci Salah
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Reinforced Concrete Frame ◽  
Nonlinear Method ◽  
Seismic Risk Analysis ◽  
Building Inventory ◽  
Concrete Frame ◽  
Capacity Curves ◽  
The North ◽  
Frame Buildings

The seismic activity remains strong in the north of Algeria since no less than 30 earthquakes per month are recorded. The large number of structures built before the introduction of the seismic standards represents a high seismic risk. Analysis of damage suffered during the last earthquakes highlighted the vulnerability of the existing structures. In this study the seismic behavior of the existing buildings in Tizi-Ouzou city, located in the north of Algeria, is investigated. To make this assessment, a database was created following a building inventory based on a set of technical folders and field visits. The listed buildings have been classified into different typologies. Only reinforced concrete frame buildings are considered in this paper. The approach adopted to estimate structures damage is based on four main steps: 1) construction of capacity curves using static nonlinear method “push-over”, 2) estimate of seismic hazard, 3) determination of performance points, and finally 4) deduction of damage levels.

scholarly journals Cost effectiveness of code base shear requirements for reinforced concrete frame structures

1978 ◽  
Vol 11 (2) ◽  
pp. 85-93
Author(s):  
D. G. Elms ◽  
D. Silvester
Keyword(s):  
Reinforced Concrete ◽  
Time History ◽  
Capital Cost ◽  
Base Shear ◽  
Reinforced Concrete Frame ◽  
Total Cost ◽  
Concrete Frame ◽  
Earthquake Losses ◽  
Frame Buildings ◽  
Code Base

The appropriateness of the overall base shear levels prescribed by
 the New Zealand Loadings Code NZS4203:1976 is investigated for reinforced concrete frame buildings. Six-storey structures were designed to different base shear levels and total costs were computed: total cost takes account of capital cost, averaged direct economic loss due to earthquakes, and indirect earthquake losses. Damage levels were obtained from computer time-history analyses. It is shown that the code base shear levels are
 of the right order of magnitude for reinforced concrete frame buildings, but that the total cost of such buildings is insensitive to design
base shear level. The increase in capital cost of a concrete frame building due to earthquake design requirements is of the order of 4%.

The effect of ground motion characteristics on the fragility analysis of reinforced concrete frame buildings in Australia

Structures ◽  
2021 ◽  
Vol 34 ◽  
pp. 3583-3595
Author(s):  
Aya Alothman ◽  
Sujith Mangalathu ◽  
Javad Hashemi ◽  
Alaa Al-Mosawe ◽  
M.D. Morshed Alam ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Ground Motion ◽  
Fragility Analysis ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Frame Buildings ◽  
Motion Characteristics

scholarly journals Rapid assessment of peak storey drift demands on reinforced concrete frame buildings

2019 ◽  
Vol 52 (3) ◽  
pp. 109-118
Author(s):  
Timothy J. Sullivan
Keyword(s):  
Reinforced Concrete ◽  
Linear Time ◽  
Rapid Assessment ◽  
Time History ◽  
Seismic Assessment ◽  
Rc Frame ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Frame Buildings ◽  
Rc Frame Buildings

The peak storey drift demands that an earthquake imposes on a building can be assessed through a detailed engineering seismic assessment or recorded if a building is instrumented. However, for the rapid seismic assessment of a large number of buildings, it is desirable to have a simplified means of estimating storey drift demands. Consequently, this paper proposes a simplified means of quickly estimating storey drift demands on reinforced concrete (RC) frame buildings. Expressions for peak storey drift demand as a function of ground motion intensity are developed by utilising concepts and simplifications available from displacement-based seismic design and assessment methods. The performance of the approach is gauged by comparing predicted storey drift demands with those obtained from rigorous non-linear time-history analyses for a number of case study buildings. The promising results suggest that the approach proposed will be useful for rapidly assessing the likelihood of damage to a range of drift-sensitive elements in modern RC frame buildings.

Fragility analysis of a subway station structure by incremental dynamic analysis

2016 ◽  
Vol 20 (7) ◽  
pp. 1111-1124 ◽  
Author(s):  
Tong Liu ◽  
Zhiyi Chen ◽  
Yong Yuan ◽  
Xiaoyun Shao
Keyword(s):  
Dynamic Analysis ◽  
Earthquake Engineering ◽  
Seismic Vulnerability ◽  
Probabilistic Method ◽  
Incremental Dynamic Analysis ◽  
Seismic Intensity ◽  
Fragility Analysis ◽  
Subway Station ◽  
Limit States ◽  
Station Structure

Fragility analysis constitutes the basis in seismic risk assessment and performance-based earthquake engineering during which the probability of a structure response exceeding a certain limit state at a given seismic intensity is sought to relate seismic intensity and structural vulnerability. In this article, the seismic vulnerability assessment of a subway station structure is investigated using a probabilistic method. The Daikai subway station was selected as an example structure and its seismic responses are modeled according to the nonlinear incremental dynamic analysis procedure. The limit states are defined in terms of the deformation and waterproof performance of the subway station structure based on the central column drift angle and the structural tension damage distribution obtained from the incremental dynamic analysis. Fragility curves were developed at those limit states and the probability of exceedance at the limit states of operational, slight damage, life safety, and collapse prevention was determined for the two seismic hazard levels. Results reveal that the proposed fragility analysis implementation procedure to the subway station structure provides an effective and reliable seismic vulnerability analysis method, which is essential for these underground structural systems considering their high potential risk during seismic events.

Evaluation of the effects of spectrum-compatible seismic excitations on the response of medium-height reinforced concrete frame buildings

2006 ◽  
Vol 33 (10) ◽  
pp. 1304-1319 ◽  
Author(s):  
Nove Naumoski ◽  
Murat Saatcioglu ◽  
Lan Lin ◽  
Kambiz Amiri-Hormozaki
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Time History ◽  
Reinforced Concrete Frame ◽  
Seismic Excitations ◽  
Period Range ◽  
Design Spectrum ◽  
Concrete Frame ◽  
Frame Buildings ◽  
Artificial Accelerograms

Spectrum-compatible seismic excitations are required when dynamic time-history analysis is used for determining the response of a structure. This paper presents results from a study on the effects of different types of spectrum-compatible excitations on the response of medium-height reinforced concrete frame buildings. Two six-storey buildings designed for Vancouver and a five-storey building designed for Montréal were used in the study. Nonlinear time-history analyses were conducted by subjecting the buildings to selected ensembles of spectrum-compatible excitations (i.e., accelerograms). The ensembles used in the study included spectrum-compatible artificial accelerograms, simulated stochastic accelerograms, and recorded earthquake accelerograms (i.e., real accelerograms) scaled to the design spectrum ordinate at the fundamental building period and to the area under the design spectrum within the predominant period range of the building. The responses of the buildings resulting from spectrum-compatible artificial accelerograms and those from scaled real accelerograms were found to be quite similar. Based on the results of this study, the scaling of real accelerograms to spectral area is preferred for obtaining spectrum-compatible accelerograms.Key words: seismic, excitation, response, spectrum, accelerogram, building, drift, curvature, ductility.

Selection of seismic excitations for nonlinear analysis of reinforced concrete frame buildings

2013 ◽  
Vol 40 (5) ◽  
pp. 411-426 ◽  
Author(s):  
Lan Lin ◽  
Nove Naumoski ◽  
Murat Saatcioglu ◽  
Simon Foo ◽  
Edmund Booth ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Nonlinear Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
History Analysis ◽  
Acceleration Time Histories ◽  
Frame Buildings ◽  
Selection Of

The selection of seismic motions is one of the most important issues for the time-history analysis of buildings. This paper discusses four different methods for obtaining spectrum-compatible acceleration time histories (i.e., accelerograms) of seismic motions. Based on these methods, four sets of accelerograms compatible with the design spectrum for Vancouver were selected for this study. These included (i) scaled real accelerograms, (ii) modified real accelerograms, (iii) simulated accelerograms, and (iv) artificial accelerograms. The selected sets were used as excitation motions in the nonlinear analysis of three reinforced concrete frame buildings designed for Vancouver. The buildings included a 4-storey, a 10-storey, and a 16-storey building, which can be considered representative of low-rise, medium-rise, and high-rise buildings, respectively. The storey shears, interstorey drifts, and curvature ductilities for beams and columns obtained from the analysis were used for the evaluation of the effects of the selected sets on the responses of the buildings. Based on the results from the analysis, scaled real accelerograms are recommended for use in time-history analysis of reinforced concrete frame buildings.

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