Steel bracing configurations for seismic retrofitting of a reinforced concrete frame

2014 ◽  
Vol 167 (1) ◽  
pp. 54-65 ◽  
Author(s):  
Ciro Faella ◽  
Carmine Lima ◽  
Enzo Martinelli ◽  
Roberto Realfonzo
Keyword(s):  
Reinforced Concrete ◽  
Seismic Retrofitting ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Steel Bracing

scholarly journals Shear Behavior of a Reinforced Concrete Frame Retrofitted with a Hinged Steel Damping System

2020 ◽  
Vol 12 (24) ◽  
pp. 10360
Author(s):  
Hyun-Do Yun ◽  
Sun-Woong Kim ◽  
Wan-Shin Park ◽  
Sun-Woo Kim
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Seismic Retrofitting ◽  
Reinforced Concrete Frame ◽  
Main Research ◽  
Torsion Spring ◽  
Concrete Frame ◽  
Energy Dissipation Capacity ◽  
Research Questions ◽  
Torsion Springs

The purpose of this study was to experimentally evaluate the effect of a hinged steel damping system on the shear behavior of a nonductile reinforced concrete frame with an opening. For the experimental test, a total of three full-scale reinforced concrete frame specimens were planned, based on the “no retrofitting” (NR) specimens with non-seismic details. The main research questions were whether the hinged steel damping system is reinforced and whether torsion springs are installed in the hinged steel damping system. From the results of the experiment, the hinged steel damping system (DR specimen) was found to be effective in seismic retrofitting, while isolating the opening of the reinforced concrete (RC) frame, and the torsion spring installed at the hinged connection (DSR specimen) was evaluated to be effective in controlling the amount of deformation of the upper and lower dampers. The strength, stiffness, and energy dissipation capacity of the DSR specimen were slightly improved compared to the DR specimen, and it was confirmed that stress redistribution was induced by the rotational stiffness of the torsion spring installed in the hinge connection between the upper and lower frames.

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.

The Mexico Earthquake of September 19, 1985—Case Studies of Seismic Strengthening for Two Buildings in Mexico City

1989 ◽  
Vol 5 (1) ◽  
pp. 153-174 ◽  
Author(s):  
D. A. Foutch ◽  
K. D. Hjelmstad ◽  
E. Del Valle Calderón ◽  
E. Figueroa Gutiérrez ◽  
R. E. Downs
Keyword(s):  
Reinforced Concrete ◽  
Mexico City ◽  
Reinforced Concrete Frame ◽  
Concrete Walls ◽  
Concrete Frame ◽  
Reinforced Concrete Walls ◽  
Steel Bracing ◽  
Geotechnical Investigations ◽  
Mexico Earthquake ◽  
The City

The earthquake that shook Mexico City on 19 September 1985, destroyed several hundred buildings and took thousands of lives. Two buildings located in the most highly damaged part of the city experienced strong shaking, but suffered only slight damage. These reinforced concrete frame buildings had been retrofit with steel bracing systems and infill reinforced concrete walls prior to the earthquake. Forced vibration tests, analytical studies and geotechnical investigations for each building have been conducted. The results indicate that the steel bracing systems strengthened the buildings and stiffened them, moving their natural periods away from the 2.0-second predominant ground period in that part of the city. Implications for the design of strengthening systems have been determined.

scholarly journals PERKUATAN SEISMIK STRUKTUR RANGKA BETON BERTULANG MENGGUNAKAN BREISING BAJA TIPE X DAN V TERBALIK

2016 ◽  
Author(s):  
Made Sukrawa ◽  
Ida Bagus Dharma Giri ◽  
I Putu Deskarta ◽  
Made Hendra Prayoga
Keyword(s):  
Reinforced Concrete ◽  
Seismic Retrofitting ◽  
Frame Structure ◽  
Seismic Load ◽  
Reinforced Concrete Structure ◽  
Reinforced Concrete Frame ◽  
Braced Frame ◽  
Concrete Frame ◽  
Conventional Analysis ◽  
Brace Frames

Abstract: Analysis of reinforced concrete frame with steel braces has been done to compare the behavior of the open frame structure with reinforced concrete structure with steel braces. Three models of 2D open frame structure with 3, 4 and 5 floors were made and analyzed in SAP2000 v17 with intermediate detailing according to Indonesian Codes for Seismic Load (SNI 1726: 2002). 3-span frame structure with a span length of 6 m and level height of 3,5 m were designed according to SNI 1726: 2002, and then re-analyzed with special detailing according to New Indonesian Codes for Seismic Load (SNI 1726: 2012). After that, it was added with braces as seismic retrofitting. Two types of braces (X and concentric inverted V) were used in this study and analyzed with conventional analysis and stage construction analysis according to their stages of implementation. From the analysis results, several structure components that analyzed according to SNI 1726:2012 provitions were experience over-stressed. After retrofitted with steel braces, those components fulfill strength provition according to SNI 2847:2013 about structural concrete regulations for buildings. In addition to that, displacements that occurs on braced frame are smaller than displacements of the open frame structure with ratio of 0.08, 0.12, and 0.18 for X-brace frames with 3,4, and 5 storey and 0.07, 0.11, and 0.16 for inverted-V brace. With staged construction analysis, displacements of  X-braced frame structure increased by 14.38%, 13.62%, and 9.98% from the conventional analysis results for structure with 3, 4,and 5 storey. For structure with inverted-V brace, displacements increased by 15.83%, 14.29%, and 10.09%.

scholarly journals PERKUATAN SEISMIK STRUKTUR RANGKA BETON BERTULANG MENGGUNAKAN BREISING BAJA TIPE X DAN V TERBALIK

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Made Sukrawa ◽  
Ida Bagus Dharma Giri ◽  
I Putu Deskarta ◽  
Made Hendra Prayoga
Keyword(s):  
Reinforced Concrete ◽  
Seismic Retrofitting ◽  
Frame Structure ◽  
Seismic Load ◽  
Reinforced Concrete Structure ◽  
Reinforced Concrete Frame ◽  
Braced Frame ◽  
Concrete Frame ◽  
Conventional Analysis ◽  
Brace Frames

Abstract: Analysis of reinforced concrete frame with steel braces has been done to compare the behavior of the open frame structure with reinforced concrete structure with steel braces. Three models of 2D open frame structure with 3, 4 and 5 floors were made and analyzed in SAP2000 v17 with intermediate detailing according to Indonesian Codes for Seismic Load (SNI 1726: 2002). 3-span frame structure with a span length of 6 m and level height of 3,5 m were designed according to SNI 1726: 2002, and then re-analyzed with special detailing according to New Indonesian Codes for Seismic Load (SNI 1726: 2012). After that, it was added with braces as seismic retrofitting. Two types of braces (X and concentric inverted V) were used in this study and analyzed with conventional analysis and stage construction analysis according to their stages of implementation. From the analysis results, several structure components that analyzed according to SNI 1726:2012 provitions were experience over-stressed. After retrofitted with steel braces, those components fulfill strength provition according to SNI 2847:2013 about structural concrete regulations for buildings. In addition to that, displacements that occurs on braced frame are smaller than displacements of the open frame structure with ratio of 0.08, 0.12, and 0.18 for X-brace frames with 3,4, and 5 storey and 0.07, 0.11, and 0.16 for inverted-V brace. With staged construction analysis, displacements of  X-braced frame structure increased by 14.38%, 13.62%, and 9.98% from the conventional analysis results for structure with 3, 4,and 5 storey. For structure with inverted-V brace, displacements increased by 15.83%, 14.29%, and 10.09%.

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.

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