Response of irregular lightly reinforced concrete frame structures in low seismic zones

2016 ◽  
Vol 20 (4) ◽  
pp. 519-533
Author(s):  
Arash Rezavandi ◽  
Chung C Fu

This article evaluates the performance of lightly reinforced concrete frames in low seismic zones. The frames under evaluation contain vertical and/or plane irregularities and are designed for gravity loads only. Nonlinear time history analysis using scaled ground motions and pushover procedure as a supplemental method is performed in this study. With the adoption of plastic hinge method, damage levels are addressed according to FEMA 356 definitions. The pivot model is considered for hysteresis behavior. The damage stage and number of formed hinges are classified for the beams and columns. A comparison between models demonstrates while the first story height may suffer minor to moderate damage levels even under low seismic intensity, the severity of damage to the asymmetric plan models can be noticeable. The pushover method results are close to that of time history analysis only for the vertical irregular frames without plane irregularity.

2013 ◽  
Vol 40 (5) ◽  
pp. 411-426 ◽  
Author(s):  
Lan Lin ◽  
Nove Naumoski ◽  
Murat Saatcioglu ◽  
Simon Foo ◽  
Edmund Booth ◽  
...  

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.


2021 ◽  
Vol 879 ◽  
pp. 213-220
Author(s):  
Halla Jasem Mohamad ◽  
Mohamad Najim Mahmood

This paper presents the predicted results of nonlinear time history analysis of 11 storey (G+10) Reinforced Concrete (RC) residential building under the effects of a strong earthquake. The paper includes studying the effects of using Lead Rubber Bearings (LRB) as base isolators to improve the performance of RC building to sustain the impact of an earthquake. It also includes the effects of the infill panels on the overall dynamic response of both fixed base and base-isolated buildings subjected to a strong earthquake. The main results that are presented in this study include the variation of roof acceleration, roof displacement, base shear with time. The effects of using LRB and including the infill panels on the storey drift are also presented. Maximum reduction in the story drift was obtained when infill panels are included in the analysis of the base isolated building. The inclusion of the infill panels has only marginal effects on the variation of roof displacement with time when the building is isolated by LRB. The main important improvements that emerged from using LRB as well as the infill panels in the analysis are the reduction of inelastic energy and upgrading the elastic one that is summed up along the period of the earthquake.


Author(s):  
Fatima Zohra Baba-Hamed ◽  
Luc Davenne

The equivalent viscous damping is a key parameter in the prediction of the maximum nonlinear response. Damping constitutes a major source of uncertainty in dynamic analysis. This paper studies the effect of using viscous damping, on the reduction of the seismic responses of reinforced concrete RC frame buildings modeled as three-dimensional multi degree of freedom (MDOF) systems, and the use of nonlinear time history analysis as a method of visualized behavior of buildings in the elastic and inelastic range. This study focuses on the implications of the available modeling options on analysis. This article illustrates the effect of using the initial or tangent stiffness in Rayleigh damping in analysis of structures.  Correspondingly, this work is also concerned with the estimation of Rayleigh, mass-proportional or stiffness-proportional damping on engineering demand parameters (EDPs). As a result of a series of considerations, a damping modeling solution for nonlinear time history analysis (NLTHA) was carried out to compute the damage index. The application example is a building designed according to reinforced concrete code BAEL 91 and Algerian seismic code RPA 99/Version 2003 under seven earthquake excitations. The simulations demonstrated the accuracy and effectiveness of the proposed method to account for all of the above effects.


2011 ◽  
Vol 255-260 ◽  
pp. 2426-2433
Author(s):  
Hui Zhi Zhang ◽  
Xiu Qin Cui

For more reasonable and convenient evaluating structure seismic performance,static elasto-plastic analysis of reinforced concrete frame is presented by pushover with different lateral load distributing modes including uniform distribution, inverted triangle distribution and self-adaption distribution adopted, custom plastic hinge, bending moment-curvity relation and bending moment-axial force correlation of each member section are acquired by Response2000, and time history analysis is used to reinforced concrete frame. It is revealed that the presented method is easy and feasiable, and can generatee stable result.


2018 ◽  
Vol 20 (1) ◽  
pp. 35
Author(s):  
Pamuda Pudjisuryadi ◽  
Benjamin Lumantarna ◽  
Ryan Setiawan ◽  
Christian Handoko

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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