scholarly journals Optimization and Effectiveness of The Placement of Energy Dissipators In Rc Frame Structures 

2021 ◽  
Author(s):  
David Jesus Dominguez
Keyword(s):  
Time History ◽  
Frame Structures ◽  
Existing Buildings ◽  
Capacity Curves ◽  
Rc Frames ◽  
Dynamic Analyses ◽  
Energy Dissipators ◽  
Lower Height ◽  
Rc Frame Structures ◽  
San Andres

Abstract This document explores and analyzes the optimization of the use and placement of energy dissipators in the bays of frame structures located in seismic zones. This study may be applied to new and existing buildings. In order to do this, three RC frames of 5, 10 and 15 stories are analyzed and compared, using four brace arrangements (Chevron braces San Andrés cross and diagonal braces (two cases)). The behavior of these frames is analyzed in terms of modal parameters, capacity curves (Push-over) and dynamic analyses (Time-History). For the study, the Lorca record of mean magnitude was used, also in this case, hysteretic dissipators have been used as they are cheap and easy to install solutions. The efficiency of the energy dissipators is improved as the frames increase in height. In the lower height frames, the use of braced solutions without any device improves the structural behavior. The ductility of all frames increases with the placement of dissipators.

Nonlinear Analysis of a RC Frame Structure with Semi-Interlayers Damaged during Wenchuan Earthquake

2010 ◽  
Vol 156-157 ◽  
pp. 467-472
Author(s):  
Peng Tao Yu ◽  
Jing Jiang Sun
Keyword(s):  
Nonlinear Analysis ◽  
Wenchuan Earthquake ◽  
Time History ◽  
Large Earthquake ◽  
Frame Structure ◽  
Nonlinear Time History Analysis ◽  
Frame Structures ◽  
Rc Frame ◽  
Rc Frame Structures ◽  
Nonlinear Time History

Under the excitation of large earthquake, structures enter into high nonlinear stage. Currently, Opensees, Perform-3d and Canny are used as the most popular nonlinear analysis procedures. The fiber model will be introduced firstly and the nonlinear analysis models in Canny are explained in detail. Then Canny2007 is used to conduct nonlinear time history analysis on a heavily damaged frame structure with interlayer in Dujiangyan during Wenchuan Earthquake. Analysis shows that the maximum inter-story drift appears between the interlayer and its upper layer, and the heavy damage agrees well with the results of damage investigation. By comparing the damage extent of frame structures with or without interlayer, it reveals that the seismic performance of RC frame structures without interlayer is obviously better than that of ones with interlayer.

Analysis of the Seismic Performance of RC Frame Structures with Different Types of Bracings

2012 ◽  
Vol 166-169 ◽  
pp. 2209-2215
Author(s):  
Zhi Xin Wang ◽  
Hai Tao Fan ◽  
Huang Juan Zhao
Keyword(s):  
Seismic Performance ◽  
Time History ◽  
Steel Tube ◽  
Frame Structure ◽  
Frame Structures ◽  
Finite Element Models ◽  
Base Shear ◽  
Concrete Filled Steel Tube ◽  
Different Types ◽  
Rc Frame Structures

Finite element models of frames with steel-bracings and with concrete filled steel tube struts are built in ETABS. Seismic performance of these models is analyzed with base-shear method, superposition of modal responses method and time history method respectively. The results show that the steel-bracings or concrete filled steel tube struts are efficient to increase the story-stiffness, and the top displacement of the frame structure decreases significantly.

Retrofitting Non-Ductile RC Frames for Seismic Resistance Using Post-Installed Shear Walls

2019 ◽  
Author(s):  
Chien-Kuo Chiu ◽  
Fu-Pei Hsiao ◽  
Wen-I Liao ◽  
Samuel Jonathan Quacoo ◽  
Chin-En Ho ◽  
...  
Keyword(s):  
Brittle Failure ◽  
Load Transfer ◽  
Shear Walls ◽  
Frame Structures ◽  
Seismic Capacity ◽  
Rc Structures ◽  
Structural Health ◽  
Rc Frames ◽  
Lateral Strength ◽  
Rc Frame Structures

Abstract Reinforced Concrete (RC) frame structures that were designed and built according to older standards can be damaged during destructive earthquakes as a result of insufficient lateral strength and/or deformation capacity. Such structures must be retrofitted to satisfy the current requirements and to survive future earthquakes. Owing to its high lateral strength and stiffness capacity of an RC wall, the post-installation of an RC wall in a non-ductile frame for retrofit is a widely used retrofitting technique. However, for frame structures with low-strength concrete, the typically used connected construction method on the interface between existing and new concrete may be not able to provide effective force transfer, and may cause unexpected brittle failure in the retrofitted structure. Such unexpected brittle failure may reduce the seismic capacity of the structure and threaten its safety. Therefore, in this experimental investigation, two retrofitting methods that use a post-installed RC wall are proposed to improve the load transfer mechanism on the interface. The first involves a wall with diagonal rebar and boundary spirals, and the second involves a wall with an additional inner frame. A typical traditional retrofitting specimen was constructed and tested for comparison. Reversed cyclic loading is used to test the seismic capacity of the specimens. Finally, post-embedded piezoceramic-based sensors were used to monitor the structural health and detect damage in one of specimens during the test. The experimental results demonstrate the effectiveness of the piezoceramic-based approach to structural health monitoring and the ability of the method to detect damage in shear governed RC structures under seismic loading.

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.

Effects of Modeling Staircases on Seismic Responses of Concrete Frames

2017 ◽  
Vol 23 ◽  
pp. 72-87 ◽  
Author(s):  
Majid Ghaderi Garakani ◽  
Saeed Mahjoubi ◽  
Shervin Maleki
Keyword(s):  
Frame Structures ◽  
Second Step ◽  
Seismic Loads ◽  
Rc Frame ◽  
Concrete Frames ◽  
Strong Earthquakes ◽  
Shell Elements ◽  
Rc Frames ◽  
Rc Frame Structures ◽  
Bracing System

Staircases in reinforced concrete (RC) frame structures have suffered severe damages in past earthquakes, despite being regarded as the main means of egress during emergencies. To make sure that staircases perform as safe passages in strong earthquakes, the performance of RC stair structures should be scrutinized under major earthquakes. In this research at first, staircases were simulated as shell elements in RC frames and analyzed under gravity loads in order to find the maximum forces and moments. In the second step, the influence of staircases on the structural behavior of RC frame structures under seismic loads was studied. The results showed that stairs act as a K-type bracing system. Furthermore, a parametric study was carried out and relations for calculating force and moment in stairs slabs that had been determined under gravity loads, were modified. In addition, affected areas of structure interacting with the stairs in an earthquake were distinguished.

scholarly journals A novel inter-story drift limit proposal for TBEC2018 and fragility prognosis with TSC2007

2021 ◽  
Vol 4 (2) ◽  
pp. 68-82
Author(s):  
Onur Onat ◽  
Burak Yön
Keyword(s):  
The Other ◽  
Frame Structures ◽  
Base Shear ◽  
Seismic Code ◽  
Dynamic Analyses ◽  
Story Drift ◽  
Safe Limits ◽  
Basic Purpose ◽  
Drift Limit ◽  
Rc Frame Structures

The basic purpose of this paper is to investigate and propose a novel inter-story drift limits for the current Turkish Seismic Code to get easy structural assessment by using software. For this aim, numerical analysis was performed by modeling two types of RC frame structures. One of them is 5 stories, the other of them is 7 stories. Two different concrete classes, C20 and C25, were considered and three tension reinforcement ratios were considered for analysis. Tension reinforcement ratios were determined by half of the compressive reinforcement, equal to compressive reinforcement and double the compressive reinforcement ratio. Incremental dynamic analyses (IDA) were performed on these buildings. In this study to execute IDA, eleven seismic acceleration benchmark records were multiplied with various scaling factors from 0.2 to 1.0. Maximum base shear and corresponding roof displacement responses obtained from IDA curves were generated according to these responses. IDA curves were compared with each other by deriving fragility graphs. According to results, proposed limits for the current Turkish seismic code (TBEC-2018) provide, 0.6%, 2.4% and 3.3% respectively for MN, GV and GC, rather safe limits compared to drift limits presented in the foredate seismic code (TSC-2007).

Effect of infill walls on cumulative plastic deformation energy of RC frame structures

2019 ◽  
Vol 16 (2) ◽  
pp. 293-305
Author(s):  
Bing Bing Tu
Keyword(s):  
Plastic Deformation ◽  
Time History ◽  
Deformation Energy ◽  
Frame Structures ◽  
Response Analysis ◽  
Seismic Action ◽  
Rc Frame ◽  
Infill Walls ◽  
Content Type ◽  
Rc Frame Structures

Purpose A large number of earthquake damages showed that infill walls have obvious influence on the seismic damage performance of RC frame structures. The purpose of this paper is to study the effect of infill walls on the cumulative plastic deformation energy of RC frame structures, for which four RC frame structures are build and the time-history response analysis under unidirectional seismic action is presented. Design/methodology/approach The time-history response analysis under unidirectional seismic action is presented. Then the effect of periodic reduction coefficient on the cumulative plastic deformation energy of the structures, the beams and the columns is investigated. Findings Finally, the quantitative calculation formulas are provided. The results show that the periodic reduction coefficient has an obvious effect on the distribution of the accumulated plastic deformation energy, and the influence rules are presented here. Originality/value The effect of infill walls on the cumulative plastic deformation energy of RC frame structures is quantitatively analyzed here.

Cumulative damage effects of mainshock-aftershock sequences on RC-frame structures

2019 ◽  
Vol 32 (3-4) ◽  
pp. 157-169
Author(s):  
Lingxin Zhang ◽  
◽  
Baijie Zhu ◽  
Yunqin Xue ◽  
Jialu Ma ◽  
...  
Keyword(s):  
Cumulative Damage ◽  
Frame Structures ◽  
Rc Frame ◽  
Aftershock Sequences ◽  
Rc Frame Structures

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.

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