Numerical Investigations on the Seismic Response of Masonry Building Aggregates

2010 ◽  
Vol 133-134 ◽  
pp. 715-720 ◽  
Author(s):  
Ilaria Senaldi ◽  
Guido Magenes ◽  
Andrea Penna
Keyword(s):  
Seismic Response ◽  
Nonlinear Dynamic ◽  
Masonry Building ◽  
Structural Units ◽  
Numerical Investigations ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Building Aggregates

The work focuses on the analysis of the seismic response of masonry building aggregates for a better understanding of the vulnerability of single structural units and of their behaviour within the aggregates. Idealized representative models are developed based on the typical characteristics of the row conglomeration typology. The seismic response of the models is evaluated and discussed by means of nonlinear dynamic analyses.

Implications of cumulated seismic damage on the seismic performance of unreinforced masonry buildings

2014 ◽  
Vol 47 (2) ◽  
pp. 157-170 ◽  
Author(s):  
Amaryllis Mouyiannou ◽  
Andrea Penna ◽  
Maria Rota ◽  
Francesco Graziotti ◽  
Guido Magenes
Keyword(s):  
Nonlinear Dynamic ◽  
Fragility Curves ◽  
Seismic Damage ◽  
Unreinforced Masonry ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Seismic Capacity ◽  
Building Stock ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses

The seismic capacity of a structure is a function of the characteristics of the system as well as of its state, which is mainly affected by previous damage and deterioration. The cumulative damage from repeated shocks (for example during a seismic sequence or due to multiple events affecting an unrepaired building stock) affects the vulnerability of masonry buildings for subsequent events. This paper proposes an analytical methodology for the derivation of state-dependent fragility curves, taking into account cumulated seismic damage, whilst neglecting possible ageing effects. The methodology is based on nonlinear dynamic analyses of an equivalent single degree of freedom system, properly calibrated to reproduce the static and dynamic behaviour of the structure. An application of the proposed methodology to an unreinforced masonry case study building is also presented. The effect of cumulated damage on the seismic response of this prototype masonry building is further studied by means of nonlinear dynamic analyses with the accelerograms recorded during a real earthquake sequence that occurred in Canterbury (New Zealand) between 2010 and 2012.

Effects of column and superstructure stiffness on the seismic response of bridges in the transverse direction

2013 ◽  
Vol 40 (8) ◽  
pp. 827-839 ◽  
Author(s):  
Payam Tehrani ◽  
Denis Mitchell
Keyword(s):  
Seismic Response ◽  
Nonlinear Dynamic ◽  
Transverse Direction ◽  
Time History ◽  
Highway Bridge ◽  
Design Code ◽  
Bridge Design ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Degree Of Irregularity

The transverse seismic responses of continuous 4-span bridges designed based on the 2006 Canadian Highway Bridge Design Code were studied using inelastic time history analyses. A total of 648 bridge configurations were considered in which the column heights, column diameters, superstructure stiffness and mass as well as abutment restraint conditions were studied. The maximum ductility demands obtained using elastic and inelastic analyses were compared to study the influence of the degree of irregularity. The effects of column stiffness ratios and superstructure to substructure stiffness ratios on the maximum ductility demands and concentration of ductility demands were investigated. A number of different regularity indices were compared to determine the suitability of these different indices in predicting the influence of irregularity. This study demonstrates the conservative nature of the 2006 Canadian Highway Bridge Design Code and provides some guidance on factors for determining the degree of irregularity and suitable regularity indices when carrying out nonlinear dynamic analyses of bridges.

The Influence of Modified Natural Records on Seismic Response of Reinforced Concrete Structure

2014 ◽  
Vol 711 ◽  
pp. 477-480
Author(s):  
Dong An ◽  
Tie Jun Qu
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Ground Motion ◽  
Nonlinear Dynamic ◽  
Reinforced Concrete Structure ◽  
Reinforced Concrete Frame ◽  
Magnitude Scaling ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Spectrum Matching

The choice of input ground motion in the evaluation of the seismic response is a complicated task. The ground motion parameters need to be determined by the scope of the analysis and the potential damage of new or existing buildings. This work presents nonlinear dynamic analyses on reinforced concrete frame widely present in China. Input ground motions contain uncertainty and variability comes from both natural recordings and modified ones. Magnitude scaling and spectrum matching are used in this study. Nonlinear dynamic analyses of reinforced concrete buildings simulated by SeismoStruct and OpenSEES are carried out to evaluate the seismic response. Findings from the investigation indicate that spectrum matching is generally stable and shows good performance in response prediction.

INFLUENCE OF ADDED VISCOUS DAMPERS ON THE PROBABILISTIC SEISMIC PERFORMANCE EVALUATION OF RC FRAMES

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Luca Landi ◽  
Cristina Vorabbi ◽  
Pier Paolo Diotallevi
Keyword(s):  
Nonlinear Dynamic ◽  
Ground Motions ◽  
Frame Structures ◽  
Rc Frame ◽  
Viscous Dampers ◽  
Fluid Viscous Dampers ◽  
Hazard Curve ◽  
Dynamic Analyses ◽  
Nonlinear Dynamic Analyses ◽  
Rc Frame Structures

This paper deals with the parameters which influence the probability of reaching the near collapse limit state of RC frame structures equipped with nonlinear fluid viscous dampers. The study can be divided into two steps. The first aims to assess how the median and the dispersion of seismic demand can vary in the RC frame structures with and without dampers, considering a wide set of ground motions. The second step evaluates the expression in closed form, given by 2000 SAC/FEMA method, to assess the annual probability of failure of RC structures. This probability has been estimated considering a wide set of ground motions and different methods to approximate the hazard curve. The evaluations have been made on the basis of the results of a large number of nonlinear dynamic analyses; in particular, 180 nonlinear dynamic analyses have been made for the case studies with and without dampers. In conclusion, it has been noticed that the probabilistic assessment depends on the number of records considered and that the simplified formula provided by the 2000 SAC-FEMA method is strongly sensitive to the variation of the hazard curve and the dispersion.

Assessment of some Canadian seismic code requirements for concrete frame structures

1991 ◽  
Vol 18 (3) ◽  
pp. 343-357
Author(s):  
Patrick Paultre ◽  
Denis Mitchell
Keyword(s):  
Nonlinear Dynamic ◽  
Combined Loading ◽  
Concrete Frame ◽  
Dynamic Analyses ◽  
Loading Effects ◽  
Real Earthquake ◽  
Strength And Stiffness ◽  
Nonlinear Dynamic Analyses ◽  
Building Designs ◽  
Current Code

Three buildings in Montreal were designed for different levels of "ductility" according to the 1990 National Building Code of Canada and the 1984 Canadian Standards Association standard for the design of concrete structures for buildings. Analytical procedures were developed in order to predict the responses of main structural components to the combined loading effects of axial load, moment, and shear. In addition, a hysteretic behavioural model was developed in order to account for strength and stiffness degradation as well as pinching of the hysteretic response. Nonlinear dynamic analyses were carried out on each building for a series of artificially generated accelerograms together with real earthquake records. The results of the nonlinear dynamic analyses enabled an assessment of the performance of different building designs and an assessment of current code requirements. Key words: seismic design, reinforced concrete, detailing, structures, codes.

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