scholarly journals Evaluation of pounding effects between reinforced concrete frames subjected to far-field earthquakes in terms of damage index

2021 ◽  
Author(s):  
S. H. Hosseini ◽  
H. Naderpour ◽  
R. Vahdani ◽  
R. Jankowski
Keyword(s):  
Reinforced Concrete ◽  
Damage Index ◽  
Seismic Intensity ◽  
Separation Distance ◽  
Coefficient Of Determination ◽  
Far Field ◽  
Concrete Frames ◽  
Rc Structures ◽  
Minimum Separation ◽  
Comparison Of The Results

AbstractIn this paper, three different damage indexes were used to detect nonlinear damages in two adjacent Reinforced Concrete (RC) structures considering pounding effects. 2-, 4- and 8-story benchmark RC Moment Resisting Frames (MRFs) were selected for this purpose with 60%, 75%, and 100% of minimum separation distance and also without any in-between separation gap. These structures were analyzed using the incremental dynamic analysis method under 44 far-field ground motion records. Comparison of the results between the MRFs with and without considering pounding effects show that collisions lead to a decrease in the values of coefficient of determination and the nonlinear damage occurs in lower seismic intensity. As a result, using the damage indexes, nonlinear damages can be detected during a specific seismic intensity. Moreover, considering a minimum separation distance leads to an increase in the coefficient of determination between the damage index and the maximum story drift ratio. Furthermore, due to pounding, shorter MRFs are damaged more significantly than the taller structures.

scholarly journals Experimental testing of medium scale GFRP reinforced concrete frames

2019 ◽  
Vol 289 ◽  
pp. 04004
Author(s):  
George Hopartean ◽  
Ted Donchev ◽  
Diana Petkova ◽  
Costas Georgopoulos ◽  
Mukesh Limbachiya ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Testing ◽  
Control Sample ◽  
Concrete Frames ◽  
Reinforced Concrete Frames ◽  
Reinforced Polymers ◽  
Rc Structures ◽  
Gfrp Bars ◽  
Glass Frp ◽  
Reversed Cyclic

Fibre reinforced polymers (FRP) have been used as strengthening for existing RC structures for many decades. Lately, there has been a lot of interest in using FRP as internal reinforcement in beams, slabs and columns. One potential area of application could be reinforced concrete frames internally reinforced with GFRP bars. With limited research in this direction, the objective of this publication is to assess the behaviour of glass FRP (GFRP) reinforced concrete frames under reversed cyclic lateral in plane loading and to analyse the seismic performances of such elements. For the purpose of this paper, experimental testing of two 1/3 scaled down frames is conducted in displacement-controlled mode with the loading history according to ACI 374.1-05. The control sample is reinforced with conventional steel reinforcement and the results obtained are compared with the sample reinforced with GFRP bars. In summary, observations on the sample behaviour at specified drift ratio such as load-displacement behaviour, envelope curves and energy dissipation are presented.

scholarly journals Development and Verification of the Capacity Curve for Two Dimensional Reinforced Concrete Moment-Resisting Frames System under Earthquake Loading

2021 ◽  
Vol 27 (6) ◽  
pp. 73-96
Author(s):  
Haider A Abass ◽  
Husain Khalaf Jarallah
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Pushover Analysis ◽  
Three Dimensional ◽  
Automatic Identification ◽  
Two Dimensional ◽  
Seismic Evaluation ◽  
Concrete Frames ◽  
Capacity Curves ◽  
Comparison Of The Results

Pushover analysis is an efficient method for the seismic evaluation of buildings under severe earthquakes. This paper aims to develop and verify the pushover analysis methodology for reinforced concrete frames. This technique depends on a nonlinear representation of the structure by using SAP2000 software. The properties of plastic hinges will be defined by generating the moment-curvature analysis for all the frame sections (beams and columns). The verification of the technique above was compared with the previous study for two-dimensional frames (4-and 7-story frames). The former study leaned on automatic identification of positive and negative moments, where the concrete sections and steel reinforcement quantities the source of these moments. The comparison of the results between the two methodologies was carried out in terms of capacity curves. The results of the conducted comparison highlighted essential points. It was included the potential differences between default and user-defined hinge properties in modeling. The effect of the plastic hinge length and the transverse of shear reinforcement on the capacity curves was also observed. Accordingly, it can be considered that the current methodology in this paper more logistic in the representation of two and three-dimensional structures.  

scholarly journals Seismic performance assessment of RC columns with interlocking hoops

2021 ◽  
Author(s):  
Tae-Hoon Kim
Keyword(s):  
Reinforced Concrete ◽  
Performance Assessment ◽  
Seismic Performance ◽  
Evaluation System ◽  
Damage Index ◽  
Seismic Performance Assessment ◽  
Rc Columns ◽  
Rc Structures ◽  
Damage Indices ◽  
Transverse Steel

The aim of this study is to analytically assess the seismic performance of reinforced concrete (RC) columns with interlocking hoops using a novel damage index, and to provide data for developing next generation seismic design criteria. Seismic performance of RC columns is controlled by the level of confinement provided by transverse steel. Interlocking hoops are commonly used in RC columns because they can provide more effective confinement than rectangular hoops. Three RC interlocking columns were tested under a constant axial load and a cyclically reversed horizontal load. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze RC structures. Novel damage indices aim to provide a means of quantifying numerically the performance level in RC columns with interlocking hoops sustained under earthquake loading. The proposed numerical method for the seismic performance assessment of interlocking columns is verified by comparison with the experimental results.

Equivalent Ductility Damage Model for Seismic Response of RC Structures: Test and Verification

2010 ◽  
Vol 163-167 ◽  
pp. 1714-1718
Author(s):  
Guang Ming Chang ◽  
Guo Hua Xing ◽  
Bo Quan Liu
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Damage Model ◽  
Damage Index ◽  
Shear Walls ◽  
Rc Structures ◽  
Index Model ◽  
Concrete Members ◽  
Ultimate Failure ◽  
Total Structure

. It is possible to quantify the damage to reinforced concrete members under cyclic loading through a nondimensional parameter known as a “damage index”. The damage index can be either a global damage index for the total structure, or a local damage index for the element level. In this paper, a new damage model termed “equivalent ductility damage model” has been suggested for evaluation of the damage index, which is consistent with accepted definitions of ductility. Substructure method was applied to verify the suggested new damage model. A total of 3 identical half-scale reinforced concrete columns were tested under variable amplitude cyclic loading up to the ultimate failure of the specimens. The imposed displacement histories were obtained from analytical simulations of the model column subjected to a series of earthquakes. Test observations indicate that the proposed model predicts 100 percent damage at the ultimate failure state of the element. The proposed damage index model can be extended to other structural elements, such as shear walls, beams, beam-column junctions, etc.

scholarly journals Seismic Retrofitting of Structures Using Steel Bracing: An Overview

2021 ◽  
Author(s):  
Silpa S ◽  
Chinsu Mereena Joy
Keyword(s):  
Reinforced Concrete ◽  
Seismic Retrofitting ◽  
Earthquake Resistance ◽  
Seismic Loads ◽  
Concrete Frames ◽  
Rc Structures ◽  
Operation Costs ◽  
Steel Bracing ◽  
The Stability ◽  
Stability Of Structures

One of the major causes of the collapse of buildings are earthquakes. Reinforced concrete structures are vulnerable to seismic activities and can destruct the structures. The RC structures which are prone to seismic activities should be protected and need to be retrofitted to resist the seismic loads. Retrofitting is one of the best methods which can be used to strengthen the structures safe against seismic loads. Retrofitting techniques will increase the strength, stiffness, ductility and stability of structures as well as reduce the operation costs and environmental impacts. Various techniques of retrofitting can be adapted to improve the stability of the structure. One of the most effective method for retrofitting of structures is the use of steel bracings. Steel bracing can be effectively used for enhancing the earthquake resistance of seismically inadequate reinforced concrete frames. This paper reviews the effect of different steel bracing patterns used as retrofitting technique in the seismic performance of the structures.

scholarly journals Seismic Fragility Analysis of the Reinforced Concrete Continuous Bridge Piers Based on Machine Learning and Symbolic Regression Fusion Algorithms

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hanbo Zhu ◽  
Changqing Miao
Keyword(s):  
Machine Learning ◽  
Reinforced Concrete ◽  
Damage Index ◽  
Regression Function ◽  
Element Model ◽  
Seismic Intensity ◽  
Symbolic Regression ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Intensity Measures

In the fragility analysis, researchers mostly chose and constructed seismic intensity measures (IMs) according to past experience and personal preference, resulting in large dispersion between the sample of engineering demand parameter (EDP) and the regression function with IM as the independent variable. This problem needs to be solved urgently. Firstly, the existing 46 types of ground motion intensity measures were taken as a candidate set, and the composite intensity measures (IMs) based on machine learning methods were selected and constructed. Secondly, the modified Park–Ang damage index was taken as EDP, and the symbolic regression method was used to fit the functional relationship between the composite intensity measures (CIMs) and EDP. Finally, the probabilistic seismic demand analysis (PSDA) and seismic fragility analysis were performed by the cloud-stripe method. Taking the pier of a three-span continuous reinforced concrete hollow slab bridge as an example, a nonlinear finite element model was established for vulnerability analysis. And the composite IM was compared with the linear composite IM constructed by Kiani, Lu Dagang, and Liu Tingting. The functions of them were compared. The analysis results indicated that the standard deviation of the composite IM fragility curve proposed in this paper is 60% to 70% smaller than the other composite indicators which verified the efficiency, practicality, proficiency, and sufficiency of the proposed machine learning and symbolic regression fusion algorithms in constructing composite IMs.

EXPERIMENTAL LIFE STUDIES OF REINFORCED CONCRETE FRAMES WITH GIRDERS REINFORCED BY INDIRECT REINFORCEMENT

2020 ◽  
Vol 87 (1) ◽  
pp. 92-100 ◽  
Author(s):  
N.V. FEDOROVA ◽  
◽  
FAN DINH GUOK ◽  
NGUYEN THI CHANG ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Frames ◽  
Reinforced Concrete Frames
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