Behaviour of reinforced concrete frames rehabilitated with concentric steel bracing

2000 ◽  
Vol 27 (3) ◽  
pp. 433-444 ◽  
Author(s):  
H Abou-Elfath ◽  
A Ghobarah
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Simplified Approach ◽  
Concrete Frame ◽  
Rc Frames ◽  
Damage Indices ◽  
Steel Bracing ◽  
Story Building

The seismic performance of low-rise nonductile reinforced concrete (RC) buildings rehabilitated using concentric steel bracing is investigated. A three-story building was analysed using various ground motion records. The effectiveness of the steel bracing in rehabilitating the three-story building was examined. The effect of the distribution of the steel bracing along the height of the RC frames on the seismic performance of the rehabilitated building was studied. The behaviour of the nonductile RC frame members is represented using a beam-column element capable of modelling the strength softening and the effects of the axial force on the yield moment and the deformation capacities at peak strength of these members. The performance of the building is evaluated in terms of global and story drifts and damage indices. A simplified approach is proposed for selecting the proper brace distribution.Key words: reinforced concrete, frame, nonductile, rehabilitation, concentric steel brace.

scholarly journals Time-dependent Seismic Performance Assessment of Corroded Reinforced Concrete Frames

2019 ◽  
Author(s):  
Mohammad Ghanooni-Bagha ◽  
Sajad Zarei ◽  
Hamid Reza Savoj ◽  
Mohsen Ali Shayanfar
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Concrete Compressive Strength ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Nonlinear Analyses ◽  
Seismic Performance Assessment ◽  
Concrete Frame ◽  
Capacity Curves ◽  
Severe Intensity

In this study, effects of reinforcement corrosion such as reinforcement cross section reduction, steel yield strength and concrete compressive strength reduction on RC member capacity decrease are studied. Next, a two-dimensional reinforced concrete moment resistant frame is modeled to evaluate the effects of moderate and severe intensity corrosion on moment-curvature behavior of elements and structure seismic response under nonlinear analysis. Structure capacity curves in push-over analysis and failure curves resulted from IDA for both the structure without and with corrosion are obtained and the effects of reinforcement’s corrosion on the reinforced concrete frame seismic performance are determined through comparing the results. The results revealed that in terms of amount, place and type of corrosion in the reinforced concrete frame, value of the reduction resisting moment of elements is different. Furthermore, the outcomes of nonlinear analyses showed that the capacity of structure is reduced and its seismic performance level is changed as a result of corrosion.

scholarly journals Seismic Performance of Reinforced Concrete Frame with Steel Bracing System

2019 ◽  
Vol 8 (3) ◽  
pp. 1029-1034
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Seismic Activity ◽  
Seismic Zone ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Steel Bracing ◽  
Different Types ◽  
Bracing System ◽  
Made In

The design of the 15 storey R.C building (seismic zone V) is made in accordance with IS 456:2000 using ETABS software. It is already reported that provision of concentric bracing throughout the building are reliable during seismic activity. Hence, this work is aimed to improve the performance of multi storey R.C. building by provision of eccentric steel bracing through analysis. Different types of bracing such as V bracing, Chevron bracing and Diagonal bracing are provided in concentric and eccentric manner. The effect of distribution of steel bracing throughout the height of the building is examined. It is found that the deflection in the building increases with increase in eccentricity. Moreover, V type bracing with 10 percentage eccentricity is found to be most reliable under seismic activity compared to other arrangements.

Seismic risk for commercial buildings in Memphis

1983 ◽  
Vol 73 (5) ◽  
pp. 1435-1450
Author(s):  
Andrzej S. Nowak ◽  
Elizabeth L. M. Rose
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Steel Structure ◽  
Structural Type ◽  
Commercial Buildings ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Damage Prediction ◽  
Concrete Frame

Abstract This paper deals with the evaluation of seismic risk for commercial buildings in Memphis, Tennessee. The seismicity of the area is summarized, and commercial buildings are divided into categories with regard to parameters such as number of stories, year of construction, assessed value, total floor area, and structural type. The distributions of these parameters are presented in the figures. During the study, over 15 buildings were examined on site by a team of experts to evaluate their seismic resistances. The quality of the design, materials, and construction was found to be surprisingly good, particularly in those structures built since 1900. Seismic resistance is analytically evaluated for five buildings: a four-story reinforced concrete frame; a four-story steel structure with vertical trusses; a 13-story stell frame; and two multi-story reinforced concrete frames. The loadings from four sources are considered: EI Centro and Taft earthquakes in California (1940 and 1952, respectively) and the forces specified in the 1979 UBC and 1981 BOCA codes. Ratios of load to capacity are calculated. For each building considered, the expected percentage of damage is evaluated for the two earthquakes. The damage prediction is extended to all commercial buildings in Memphis.

Seismic Performance Evaluation for Steel Reinforced Concrete Frame Structures

2011 ◽  
Vol 255-260 ◽  
pp. 2421-2425
Author(s):  
Qiu Wei Wang ◽  
Qing Xuan Shi ◽  
Liu Jiu Tang
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Seismic Performance Evaluation ◽  
Steel Reinforced Concrete ◽  
Concrete Frame ◽  
Structural Capacity ◽  
Reinforced Concrete Frame Structures ◽  
Dynamic Nonlinear Analysis

The randomness and uncertainty of seismic demand and structural capacity are considered in demand-capacity factor method (DCFM) which could give confidence level of different performance objectives. Evaluation steps of investigating seismic performance of steel reinforced concrete structures with DCFM are put forward, and factors in calculation formula are modified based on stress characteristics of SRC structures. A regular steel reinforced concrete frame structure is analyzed and the reliability level satisfying four seismic fortification targets are calculated. The evaluation results of static and dynamic nonlinear analysis are compared which indicates that the SRC frame has better seismic performance and incremental dynamic analysis could reflect more dynamic characteristics of structures than pushover method.

Seismic performance of ductile medium height reinforced concrete frame buildings designed in accordance with the provisions of the 1995 National Building Code of Canada

1999 ◽  
Vol 26 (5) ◽  
pp. 606-617 ◽  
Author(s):  
A C Heidebrecht ◽  
N Naumoski
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Frame Structure ◽  
Performance Criteria ◽  
Building Code ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Interstorey Drift

This paper describes an investigation into the seismic performance of a six-storey ductile moment-resisting frame structure located in Vancouver and designed and detailed in accordance with the seismic provisions of the National Building Code of Canada (1995). Both pushover and dynamic analyses are conducted using an inelastic model of the structure as designed and detailed. The structural performance of a number of design variations is evaluated using interstorey drift and member curvature ductility response as performance measures. All frames studied are expected to perform at an operational level when subjected to design level seismic excitations and to meet life safe performance criteria at excitations of twice the design level.Key words: seismic, building, frames, ductile, design, performance, reinforced concrete, code.

scholarly journals Experimental Study on Seismic Retrofitting of Reinforced Concrete Frames Using Welded Concrete-Filled Steel Tubes

2020 ◽  
Vol 10 (20) ◽  
pp. 7061 ◽  
Author(s):  
Kyong Min Ro ◽  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Seismic Energy ◽  
Maximum Load ◽  
Steel Tube ◽  
Seismic Retrofitting ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Moment Resisting Frames ◽  
Moment Resisting

Buildings constructed with non-seismic details are at risk of damage and collapse when an earthquake occurs due to a lack of strength, stiffness, and ductility. For reinforced concrete (RC) moment-resisting frames, seismic retrofitting methods that can enhance strength or ductility should be applied. However, such strategies have many disadvantages related to constructability, serviceability, securing integrity, and cost. In this paper, a welded concrete-filled steel tube (WCFST) system was examined in order to resolve the problems of the existing seismic retrofitting methods for RC moment-resisting frames. To evaluate the seismic performance of the proposed system, two specimens, one with non-seismic details and another reinforced with a WCFST seismic system, were manufactured for the cyclic loading tests. As a result of the experiments, the specimen retrofitted with the WCFST system showed maximum load, effective stiffness, and energy dissipation capacity values approximately 3, 2, and 2.5 times greater, respectively, than those obtained from the existing reinforced concrete frame specimen. The experimental results indicate that the proposed WCFST system is expected to be effective at improving the seismic performance by enhancing both the strength of the existing reinforced concrete frame structures and the dissipation of the seismic energy.

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