Evaluation of Seismic Damage Indices for Concrete Elements Loaded in Combined Shear and Flexure

10.14359/483 ◽  
1997 ◽  
Vol 94 (3) ◽  
Keyword(s):  
Seismic Damage ◽  
Damage Indices ◽  
Concrete Elements

Seismic Damage Analysis on the Continuous Girder Bridge of Urban Rail Transit Line

2014 ◽  
Vol 488-489 ◽  
pp. 398-402 ◽  
Author(s):  
Hai Qing Li ◽  
Yong Jun Ni ◽  
Xin Gang Liu ◽  
Jin Xing Yan
Keyword(s):  
Seismic Performance ◽  
Evaluation Method ◽  
Research Direction ◽  
Seismic Damage ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Damage Analysis ◽  
Seismic Performance Evaluation ◽  
Damage Indices ◽  
Urban Rail

Seismic damage was the key reason which resulted in the serviceability degradation or collapse of the bridge. How to quantify the seismic damage and evaluate the seismic performance of the bridge under earthquakes through the damage analysis was the significant research direction in the performance based seismic design. In this paper the Park-Ang model (a well-known dual parameters model) and its modification version used for the damage evaluation of the concrete structure were compared. Furthermore, through the definition of the damage indices of the models based on the modified Park-Ang model and the descending slope of the IDA(incremental dynamic analysis) curve, the seismic damage levels of the typical bridge in the urban rail transit line under the designated earthquakes were analyzed, respectively. It was shown from the results that the calculated results from the two model was essentially consistent. The damage analysis based evaluation method was feasibly used for the seismic performance evaluation of the bridge.

scholarly journals Hybrid backpropagation neural network-particle swarm optimization for seismic damage building prediction

2019 ◽  
Vol 14 (1) ◽  
pp. 360
Author(s):  
Marina Yusoff ◽  
Faris Mohd Najib ◽  
Rozaina Ismail
Keyword(s):  
Neural Network ◽  
Particle Swarm Optimization ◽  
Damage Index ◽  
Particle Swarm ◽  
Seismic Damage ◽  
Backpropagation Neural Network ◽  
Swarm Optimization ◽  
Local Optima ◽  
Damage Indices ◽  
Prediction Problems

The evaluation of the vulnerability of buildings to earthquakes is of prime importance to ensure a good plan can be generated for the disaster preparedness to civilians. Most of the attempts are directed in calculating the damage index of buildings to determine and predict the vulnerability to certain scales of earthquakes. Most of the solutions used are traditional methods which are time consuming and complex. Some of initiatives have proven that the artificial neural network methods have the potential in solving earthquakes prediction problems. However, these methods have limitations in terms of suffering from local optima, premature convergence and overfitting. To overcome this challenging issue, this paper introduces a new solution to the prediction on the seismic damage index of buildings with the application of hybrid back propagation neural network and particle swarm optimization (BPNN-PSO) method. The prediction was based on damage indices of 35 buildings around Malaysia. The BPNN-PSO demonstrated a better result of 89% accuracy compared to the traditional backpropagation neural network with only 84%. The capability of PSO supports fast convergence method has shown good effort to improve the processing time and accuracy of the results.

Seismic Damage Indices for Concrete Structures: A State-of-the-Art Review

1995 ◽  
Vol 11 (2) ◽  
pp. 319-349 ◽  
Author(s):  
Martin S. Williams ◽  
Robert G. Sexsmith
Keyword(s):  
Accurate Determination ◽  
Concrete Structures ◽  
Weighted Average ◽  
Structural Type ◽  
Seismic Damage ◽  
Individual Element ◽  
Damage Indices ◽  
Modes Of Failure ◽  
Before And After ◽  
Modes Of Vibration

This paper gives a review of seismic damage indices, with particular reference to their use in retrofit decision making. Damage indices aim to provide a means of quantifying numerically the damage in concrete structures sustained under earthquake loading. Indices may be defined locally, for an individual element, or globally, for a whole structure. Most local indices are cumulative in nature, reflecting the dependence of damage on both the amplitude and the number of cycles of loading. The main disadvantages of most local damage indices are the need for tuning of coefficients for a particular structural type and the lack of calibration against varying degrees of damage. Global damage indices may be calculated by taking a weighted average of the local indices throughout a structure, or by comparing the modal properties of the structure before and after (and sometimes during) the earthquake. The weighted-average indices are prone to much the same problems as the local indices. The modal indices vary widely in their level of sophistication, those capable of detecting relatively minor damage requiring the accurate determination of a large number of modes of vibration. The development and application of damage indices has until now concentrated almost exclusively on flexural modes of failure; there is a clear need to investigate the ability of the indices to represent shear damage.

scholarly journals Seismic Damage Behavior of Aeolian Sand Concrete Columns with an Inner Square Steel Tube

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yaohong Wang ◽  
Zeping Zhang ◽  
Qing Han ◽  
Qi Chu ◽  
Xiaoyan Ma
Keyword(s):  
Damage Model ◽  
Concrete Columns ◽  
Seismic Damage ◽  
Steel Tube ◽  
Aeolian Sand ◽  
Loading Test ◽  
Damage Behavior ◽  
Damage Indices ◽  
Study Results ◽  
Square Steel Tube

In order to promote the application of aeolian sand in steel-concrete composite structures, the aeolian sand concrete columns with an inner square steel tube is proposed in this paper. This kind of column is composed of aeolian sand concrete, reinforcing steel, and an inner square steel tube. The seismic damage behavior of the column was studied through cyclic loading test and damage analysis on seven specimens with different structural forms. The seismic damage indices of the specimens in this study include the failure mode, bearing capacity, ductility, stiffness, hysteresis behavior, and energy dissipation. Then, a damage model of this kind of column is proposed. The study results show that installing an inner square steel tube can significantly improve the seismic damage behavior of aeolian sand concrete columns. This mode of construction can be used to enhance the replacement percentage of aeolian sand. In addition, the damage model proposed in this paper agrees well with the experimental results and can be used to evaluate the damage degree of the aeolian sand concrete columns with an inner square steel tube.

scholarly journals Earthquake Damage Assessment for RC Structures Based on Fuzzy Sets

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Haoxiang He ◽  
Maolin Cong ◽  
Yongwei Lv
Keyword(s):  
Reinforced Concrete ◽  
Damage Assessment ◽  
Pushover Analysis ◽  
Damage Index ◽  
Seismic Damage ◽  
Assessment Method ◽  
Energy Concentration ◽  
Fuzzy Evaluation ◽  
Damage Indices ◽  
Seismic Damage Assessment

A global damage index based on multiple linear force-deformation curves in pushover analysis is presented to evaluate the integrated damage of reinforced concrete structure. The modified coefficient is provided considering the cyclic load and hysteresis energy. The number of inelastic cycles and the coefficient of hysteresis energy concentration are also introduced as damage indices. Hence, multiple damage indices about displacement and energy for performance-based design are considered. The relation of multiple damage indices or factors and the fuzzy damage set is presented by comprehensive fuzzy evaluation; hence, a performance-based multiple fuzzy seismic damage-assessment method for reinforced concrete frame structures is established. The method can be accomplished based on pushover analysis, code spectrum, and capacity spectrum method. The fuzzy seismic damage-assessment method is verified through nonlinear analysis four different structures and the corresponding results and assessment conclusions are accurate.

scholarly journals Wavelet Packet Singular Entropy-Based Method for Damage Identification in Curved Continuous Girder Bridges under Seismic Excitations

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4272 ◽  
Author(s):  
Dayang Li ◽  
Maosen Cao ◽  
Tongfa Deng ◽  
Shixiang Zhang
Keyword(s):  
Optical Sensors ◽  
Wavelet Packet ◽  
Robustness Analysis ◽  
Element Model ◽  
Seismic Damage ◽  
Dynamic Responses ◽  
Seismic Excitation ◽  
Normal Operation ◽  
Girder Bridges ◽  
Damage Indices

Curved continuous girder bridges (CCGBs) have been widely adopted in the civil engineering field in recent decades for complex interchanges and city viaducts. Unfortunately, compared to straight bridges, this type of bridge with horizontal curvature is relatively vulnerable to earthquakes characterized by large energy and short duration. Seismic damage can degrade the performance of CCGBs, threatening their normal operation and even resulting in collapse. Detection of seismic damage in CCGBs is thus significantly important but is still not well resolved. To this end, a new method based on wavelet packet singular entropy (WPSE) is proposed to identify seismic damage by analyzing the dynamic responses of CCGBs to seismic excitation. This WPSE-based approach features characterizing damage using synergistic advantage of the wavelet packet transform, singular value decomposition, and information entropy. To testify the algorithm, a finite element model of a typical CCGB with two types of seismic damage is built, in which the seismic damage is individually modeled by stiffness reductions at the bottom of piers and at pier-girder connections. The displacement responses of the model to El Centro seismic excitation is used to identify the damage. The results show that damage indices in the WPSE-based approach can correctly locate the seismic damage in CCGBs. Furthermore, the WPSE-based method is competent to identify damage with higher accuracy in comparison with the wavelet packet energy based method, and has a strong immunity to noise revealed by robustness analysis. An array of responses used in this approach paves the way of developing practical technologies for detecting seismic damage using advanced distributed sensing techniques, typically the optical sensors.

Vibration-Based Condition Monitoring of Smart Prefabricated Concrete Elements

2005 ◽  
Vol 293-294 ◽  
pp. 743-752 ◽  
Author(s):  
Daniele Zonta ◽  
Matteo Pozzi ◽  
Marco Forti ◽  
Paolo Zanon
Keyword(s):  
Fiber Optics ◽  
Optical Switch ◽  
Research Effort ◽  
Damage Scenarios ◽  
Damage Indices ◽  
Bridge Structures ◽  
Statics And Dynamics ◽  
Extent Of Damage ◽  
The University ◽  
Concrete Elements

The University of Trento is promoting a research effort aimed at developing an innovative distributed construction system based on smart prefabricated concrete elements that can allow real-time assessment of the condition of bridge structures. So far, two reduced-scale prototypes have been produced, each consisting of a 0.2×0.3×5.6m RC beam specifically designed for permanent instrumentation with 8 long-gauge Fiber Optics Sensors (FOS) at the lower edge. The sensors employed are FBG-based and can measure finite displacements both in statics and dynamics. The acquisition module uses a single commercial interrogation unit and a softwarecontrolled optical switch, allowing acquisition of dynamic multi-channel signals from FBG-FOS, with a sample frequency of 625 Hz per channel. The performance of the system is undergoing validation in the laboratory. The scope of the experiment is to correlate changes in the dynamic response of the beams with different damage scenarios, using a direct modal strain approach. Each specimen is dynamically characterized in the undamaged state and in different condition states, simulating different cracking levels. The location and the extent of damage are evaluated through the calculation of damage indices which take into account changes in frequency and in strain-modeshapes. This paper presents in detail the results of the experiment as conducted on one of these prototypes and demonstrates how the damage distribution detected by the system is fully compatible with the damage extent appraised by inspection.

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