scholarly journals Seismic Retrofit of Reinforced Concrete Frame Buildings with Hysteretic Bracing Systems: Design Procedure and Behaviour Factor

2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Antonio Di Cesare ◽  
Felice Carlo Ponzo
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Passive Control ◽  
Design Procedure ◽  
Systems Design ◽  
Seismic Retrofitting ◽  
Design Parameters ◽  
Reinforced Concrete Frame ◽  
Simplified Approach ◽  
Behaviour Factor

This paper presents a design procedure to evaluate the mechanical characteristics of hysteretic Energy Dissipation Bracing (EDB) systems for seismic retrofitting of existing reinforced concrete framed buildings. The proposed procedure, aiming at controlling the maximum interstorey drifts, imposes a maximum top displacement as function of the seismic demand and, if needed, regularizes the stiffness and strength of the building along its elevation. In order to explain the application of the proposed procedure and its capacity to involve most of the devices in the energy dissipation with similar level of ductility demand, a simple benchmark structure has been studied and nonlinear dynamic analyses have been performed. A further goal of this work is to propose a simplified approach for designing dissipating systems based on linear analysis with the application of a suitable behaviour factor, in order to achieve a widespread adoption of the passive control techniques. At this goal, the increasing of the structural performances due to the addition of an EDB system designed with the above-mentioned procedure has been estimated considering one thousand case studies designed with different combinations of the main design parameters. An analytical formulation of the behaviour factor for braced buildings has been proposed.

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.

Parametric Reliability Analysis of the Seismic Bearing Capacity of Bottom Columns in Reinforced Concrete Frame Structure

2012 ◽  
Vol 204-208 ◽  
pp. 2478-2482
Author(s):  
You Bao Jiang ◽  
Yu Lai Zhao ◽  
Wei Jun Yang ◽  
Zhi Ling Gong
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Seismic Design ◽  
Reliability Index ◽  
Concrete Strength ◽  
Design Parameters ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Parametric Reliability ◽  
Seismic Bearing Capacity

After the Wenchuan earthquake, Chinese Code for Seismic Design of Buildings (GB50011-2010) adjusts some seismic design parameters. Taking into account the randomness of gravity load and earthquake action and the uncertainty of steel strength and concrete strength, this paper analyzes the reliability of seismic bearing capacity of reinforced concrete frame bottom columns. Based on the structural analysis software PKPM, which is in accordance with code for seismic design of buildings, the reliability index of seismic bearing capacity of reinforced concrete frame bottom columns is calculated by the Monte Carlo method with different parameters, such as different seismic intensity, different building storey number, different seismic adjustment coefficient (increment coefficient of frame columns end moment and increment coefficient of design value of combination moment of underlying frame columns lower end section), different horizontal span number, different column location (side column and interior column) and so on. The results indicate that the reliability index can reach 2.0 or above, and can meet the target requirements for all cases which are designed with the current code for seismic design of buildings (GB50011-2010).

scholarly journals Influencing factors of residual drifts of precast segmental bridge columns with energy dissipation bars

2018 ◽  
Vol 22 (1) ◽  
pp. 126-140 ◽  
Author(s):  
Zhong-Kui Cai ◽  
Zheng Zhou ◽  
Zhenyu Wang
Keyword(s):  
Energy Dissipation ◽  
Influencing Factors ◽  
Design Procedure ◽  
Bridge Columns ◽  
Hysteretic Behavior ◽  
Design Parameters ◽  
Seismic Capacity ◽  
Residual Drift ◽  
Bridge Column ◽  
Segmental Bridge

The energy dissipation bar has been proven to be an effective way to improve the lateral strength and the seismic capacity of the precast segmental bridge column. To date, however, investigations on how the main design parameters affect the residual drift of such bridge columns are quite limited. Focusing on this research gap, a novel numerical simulation method was proposed in this article to investigate the influencing factors of residual drift of precast segmental bridge columns with energy dissipation bars. First, the refined fiber element model was developed based on the OpenSees software package, considering the bond slip phenomenon at the column end and the boundary condition at the interface between the two adjacent segments. Then, the proposed numerical model was validated by comparing the simulated hysteretic behavior of the precast segmental bridge columns with available experimental data. After that, cyclic analyses were performed on 288 precast segmental bridge column models with different design parameters. Four important influencing factors were investigated, including the post-tensioning force, gravity load, energy dissipation bar ratio, and shear span ratio. According to the analysis results, some suggestions were provided for the practical design procedure of the energy dissipation bar reinforced precast segmental bridge columns.

Experiment Study on Reinforced Concrete Spatial Joints Subjected to Cyclic Loading

2011 ◽  
Vol 250-253 ◽  
pp. 2744-2748
Author(s):  
Chun Yang Liu ◽  
Zhen Bao Li ◽  
Hua Ma ◽  
Jian Qiang Han ◽  
Shi Cai Chen
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Damage Mechanism ◽  
Experiment Study ◽  
Reinforced Concrete Frame ◽  
Displacement Ductility ◽  
Concrete Frame ◽  
Oblique Direction ◽  
Earthquake Effect ◽  
Designing Method

Experiments on reinforced concrete frame spatial joints are conducted under low level cyclic loadings.The seismic performance of the spatial joints is investigated,including failure mode,hysterisis curve, stiffness degradation,energy dissipation and displacement ductility.The experiment result shows that the column-hinge damage mechanism had happened and the bearing capactity ,energy dissipation character and displacement ductility had decreased under the oblique direction earthquake effect.The aseismic designing method should consider the oblique direction earthquake effect.

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%.

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