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

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.

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A new damage index for seismic fragility analysis of reinforced concrete columns

STRUCTURAL ENGINEERING AND MECHANICS ◽

10.12989/sem.2016.60.5.875 ◽

2016 ◽

Vol 60 (5) ◽

pp. 875-890 ◽

Cited By ~ 2

Author(s):

Jun Won Kang ◽

Jeeho Lee

Keyword(s):

Reinforced Concrete ◽

Damage Index ◽

Concrete Columns ◽

Fragility Analysis ◽

Seismic Fragility ◽

Reinforced Concrete Columns

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The Effects of Earthquake Significant Duration D595 to the Earthquake Intensity Measures and the Inelastic Response of SDOF Reinforced Concrete Structure

MATEC Web of Conferences ◽

10.1051/matecconf/201928001005 ◽

2019 ◽

Vol 280 ◽

pp. 01005

Author(s):

Widodo Pawirodikromo

Keyword(s):

Spectral Response ◽

Damage Index ◽

Structural Response ◽

Strong Relationship ◽

Seismic Intensity ◽

Reinforced Concrete Structure ◽

Earthquake Intensity ◽

Intensity Measures ◽

Earthquake Frequency

The concept of seismic intensity measures has long beendiscussed and has been collected by researchers among whom are by [1-6]. However, the effect of earthquake duration on the structural response hasnot received attention from the researcher so it has not been seen in the listof the existing seismic intensity measures. In the spectral response, forexample, it has been accommodated peak value and earthquake frequencycontent but has not accommodated the duration of the earthquake. Theeffect of earthquake duration on a response, damage or collapse capacity ofthe structure has been done by the researchers [7-10]. The spectrallyequivalent approach/control has been used by [9,10]., while the collapsecapacity approach is cursed by [8]. The use of the classification of theearthquake frequency content as independent variables has been suggestedby [7]. In this study, the classification of earthquake frequency (lowfrequency), earthquake duration as the independent variable and peakacceleration control have been used. Single degree of Freedom (SDOF)structures excited by 15-earthquakes with effective durations varyingbetween te = 6.34 to 30.18 s have been used. The results showed that notall seismic intensity measure used had a strong relationship with effectiveduration. The earthquake effective duration has a positive relationship withthe damage index but the relationship is relatively weak

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Seismic fragility analysis of steel reinforced concrete frame structures based on different engineering demand parameters

Journal of Building Engineering ◽

10.1016/j.jobe.2018.09.019 ◽

2018 ◽

Vol 20 ◽

pp. 736-749 ◽

Cited By ~ 7

Author(s):

Chengxiang Xu ◽

Jie Deng ◽

Sheng Peng ◽

Chengyu Li

Keyword(s):

Reinforced Concrete ◽

Fragility Analysis ◽

Seismic Fragility ◽

Frame Structures ◽

Reinforced Concrete Frame ◽

Steel Reinforced Concrete ◽

Concrete Frame ◽

Reinforced Concrete Frame Structures ◽

Engineering Demand Parameters

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Fragility analysis of a long-span transmission tower–line system under wind loads

Advances in Structural Engineering ◽

10.1177/1369433220903983 ◽

2020 ◽

Vol 23 (10) ◽

pp. 2110-2120

Author(s):

Li Tian ◽

Xin Zhang ◽

Xing Fu

Keyword(s):

Damage Index ◽

Element Model ◽

Attack Angle ◽

Fragility Analysis ◽

Wind Loads ◽

Collapse Mechanism ◽

Ultimate Capacity ◽

Transmission Tower ◽

Line System ◽

Long Span

Numerous transmission towers have collapsed due to experiencing strong winds; therefore, the purpose of this article is to investigate the collapse mechanism and the anti-collapse performance of a long-span transmission tower–line system. The detailed finite element model of a typical tower–line system is established in ABAQUS. A global damage index is proposed to quantitatively estimate the overall damage of the structure and define the collapse criteria. An incremental dynamic analysis is performed to obtain the collapse mechanism and the ultimate capacity of the structure. Subsequently, a fragility analysis for evaluating the anti-collapse performance is conducted due to the uncertainty of wind loads. Eventually, the influence of the wind attack angle and the length of the side spans on the fragility is discussed. The results demonstrate that the proposed global damage index is capable of quantitatively reflecting the overall damage and assessing the ultimate capacity of the structure. In addition, the uncertainty of the wind load has a significant influence on the ultimate capacity and the failure position. Furthermore, the results reveal that the wind attack angle and the length of the side spans have an apparent effect on the fragility of the structure.

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Seismic fragility analysis of reinforced concrete continuous span bridges with irregular configuration

Structure and Infrastructure Engineering ◽

10.1080/15732471003653017 ◽

2012 ◽

Vol 8 (9) ◽

pp. 873-889 ◽

Cited By ~ 13

Author(s):

Reza Akbari

Keyword(s):

Reinforced Concrete ◽

Fragility Analysis ◽

Seismic Fragility

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

Bulletin of Earthquake Engineering ◽

10.1007/s10518-021-01259-x ◽

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.

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A method of seismic performance evaluation based seismic fragility analysis

MATEC Web of Conferences ◽

10.1051/matecconf/201817504036 ◽

2018 ◽

Vol 175 ◽

pp. 04036 ◽

Cited By ~ 1

Author(s):

Feng Wang ◽

Zhongzheng Guo

Keyword(s):

Dynamic Analysis ◽

Seismic Performance ◽

Damage Index ◽

Structural Models ◽

Seismic Damage ◽

Damage Parameter ◽

Fragility Analysis ◽

Seismic Fragility ◽

Damage Level ◽

Seismic Performance Evaluation

For evaluating seismic performance of structures, a method is presented based on increment dynamic analysis and seismic fragility analysis. Firstly, the failure probability equation is deduced, in which the relationships of seismic intensities and response demands can be determined by the increment dynamic analysis. On this basis the probabilities with different damage levels under different seismic intensities are obtained. Secondly, damage parameter R is defined and used to reflect seismic damage level of structures, damage index Re is defined and used to compare with R range and determine the situation of seismic damage. Finally, the procedure is proposed for evaluating structural seismic performance. In order to verify and demonstrate the method, three structural models are designed, and typical earthquake records are selected. The results of example analysis show that this method is convenient for evaluating multi-levels seismic performance of structures.

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