scholarly journals Seismic Damage Probability Assessment of Isolated Girder Bridges Based on Performance under Near-Field Earthquakes

2021 ◽  
Vol 11 (20) ◽  
pp. 9595
Author(s):  
Qiang Liu ◽  
Chunyan Yang
Keyword(s):  
Structural Parameters ◽  
Fragility Curves ◽  
Damage Index ◽  
Seismic Damage ◽  
Seismic Fragility ◽  
Bridge Structure ◽  
Safety Control ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Isolated Bridge

This paper presents a copula technique for developing seismic fragility curves for an RC (reinforced concrete) isolated continuous girder bridge, by considering earthquake damage indicators such as bridge piers, isolated bearing components, and the main girder of collision damage. The results of this method are compared with those of the limit method of the first-order reliability theory. Meanwhile, the incremental dynamic analysis of the bridge structure under different failure conditions is carried out, and the randomness of the near-fault ground motion and the structural parameters are accounted. Based on the damage index of the isolated bridge under different damage conditions, the seismic fragility curves of each component and the whole isolated bridge are obtained. The research shows that the safety control of the isolated continuous girder bridge structure is mainly affected by the seismic fragility of the isolated bearing, the influence of bridge pier seismic fragility is relatively small, and the probability of beam collision in an isolated bridge is lower than that of a general bridge without isolation bearing. By applying the isolation scheme, the probability of different damage state of the bridge structure is greatly reduced, thus the seismic performance is improved. It also verifies the efficiency and superiority of copula technology. The results will provide a reference for future seismic damage prediction.

SVM Based Seismic Fragility Analysis for RC Isolated Continuous Girder Bridge

2013 ◽  
Vol 800 ◽  
pp. 229-235 ◽  
Author(s):  
Xiao Hong Long ◽  
Bei Lei Chen ◽  
Jian Jun Li
Keyword(s):  
Fragility Curves ◽  
Longitudinal Direction ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Research Report ◽  
Lateral Direction ◽  
Probabilistic Seismic Demand Analysis ◽  
Continuous Girder Bridge ◽  
Probabilistic Seismic Demand ◽  
Girder Bridge

Because the fragility analysis methods used in recent years have some disadvantages to some extent, and there is no relative research report on the seismic fragility of structures based on SVM algorithm, nonparametric analytical method is used in the probabilistic seismic demand analysis, and fragility curves of RC isolated continuous bridge are obtained based on SVM Method. It turns out that the analytical results of SVM Method and Cloud Method are different in the longitudinal direction, matched in the lateral direction, and the results of the former method are greater than the latter one. It is a new and meaningful research that is more efficient than IDA method and also reliable.

scholarly journals Embankment seismic fragility assessment: A case study on Xi’an-Baoji expressway (China)

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246407
Author(s):  
Fa Che ◽  
Chao Yin ◽  
Xingkui Zhao ◽  
Zhinan Hu ◽  
Lu Sheng ◽  
...  
Keyword(s):  
Fragility Curves ◽  
Retaining Wall ◽  
Seismic Damage ◽  
Damage Parameter ◽  
Seismic Fragility ◽  
Response Analysis ◽  
Rc Structures ◽  
Fill Soil ◽  
Soil Foundation ◽  
Wall System

Although embankment seismic damages are very complex, there has been little seismic fragility research yet. Researches on seismic fragility of bridges, dams and reinforced concrete (RC) structures have achieved fruitful results, which can provide references for embankment seismic fragility assessment. Meanwhile, the influencing degrees of retaining structures, such as retaining walls on the embankment seismic performances are still unclear. The K1025+470 embankment of the Xi’an-Baoji expressway was selected as the research object, and the finite difference models of the embankment fill-soil foundation system and embankment fill-soil foundation-retaining wall system were established. The ground-motion records for Incremental Dynamic Analysis (IDA) were selected and the dynamic response analysis were conducted. Probabilistic Seismic Demand Analysis (PSDA) was used to deal with the IDA results and the seismic fragility curves were generated. Based on the assessment results, the influences of the retaining wall on the embankment seismic fragility were further verified. The research results show that regardless of which seismic damage parameter is considered or the presence or absence of the retaining wall, larger PGAs always correspond to higher probabilities of each seismic damage grade. Seismic damages to the embankment fill-soil foundation-retaining wall system are always lower than those of the embankment fill-soil foundation system under the same PGA actions, thus, the retaining wall can decrease the embankment seismic fragility significantly.

scholarly journals A method of seismic performance evaluation based seismic fragility analysis

2018 ◽  
Vol 175 ◽  
pp. 04036 ◽  
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.

Seismic Fragility Analysis of RC Isolated Continuous Girder Bridge Using Radial Basis Function Neural Network

2014 ◽  
Vol 936 ◽  
pp. 1473-1478
Author(s):  
Bei Lei Chen ◽  
Xiao Hong Long ◽  
Jian Jun Li
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Basis Function ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Mathematical Relationship ◽  
New Approach ◽  
Bridge Structures ◽  
Continuous Girder Bridge ◽  
Girder Bridge

To approximate the correlating mathematical relationship between many earthquake records PGA and the responses of bridge structures with minimum efforts and without loss of accuracy, an artificial neural network-based method is proposed in combination with LHS and IDA method. This method is employed to conduct the seismic fragility analysis of RC isolated continuous girder bridge. To investigate the suitability of this approach, the results of the new approach are compared to those obtained by the Cloud method. The comparison shows that the new method is more efficient and reliable.

scholarly journals Seismic Fragility Analysis of Buildings Based on Double-Parameter Damage Models considering Soil-Structure Interaction

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Panpan Zhai ◽  
Peng Zhao ◽  
Yang Lu ◽  
Chenying Ye ◽  
Feng Xiong
Keyword(s):  
Soil Structure ◽  
Fragility Curves ◽  
Damage Index ◽  
Fragility Analysis ◽  
Soil Structure Interaction ◽  
Seismic Fragility ◽  
Rc Buildings ◽  
Structure Interaction ◽  
Damage Models ◽  
Fixed Model

Most conventional seismic fragility analyses of RC buildings usually ignore or greatly simplify the soil-structure interaction (SSI), and the maximum interstory drift ratio (MIDR) is often adopted to establish seismic fragility curves. In this work, an eight-story RC building was designed to study the influence of the SSI on the seismic fragility of RC buildings. Three double-parameter damage models (DPDMs) were considered for the fragility assessment: the Park–Ang model, the Niu model, and the Lu–Wang model. Results show that considering SSI induces a higher fragility than that of the fixed model and that employing the DPDMs for the fragility analysis provides more reasonable results than those evaluated using the MIDR damage index.

scholarly journals Lateral Seismic Fragility Assessment of Cable-Stayed Bridge with Diamond-Shaped Concrete Pylons

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Chao Zhang ◽  
Jianbin Lu ◽  
Zhengan Zhou ◽  
Xueyuan Yan ◽  
Li Xu ◽  
...  
Keyword(s):  
Fragility Curves ◽  
Damage Index ◽  
Element Model ◽  
Seismic Fragility ◽  
Limit States ◽  
Probabilistic Estimation ◽  
Cable Stayed Bridge ◽  
Damage Probability ◽  
Damage States ◽  
The Finite Element Model

The cable-stayed bridge with diamond-shaped pylons is one of the most popular bridges because of its obvious advantages such as aesthetical appearance and smaller foundation. However, the diamond-shaped pylons have both inward and outward inclinations, which may result in complicated seismic behavior when subjected to lateral earthquake excitations. To end this, the finite element model of a cable-stayed bridge with diamond concrete pylon is developed firstly. Four limit states and corresponding damage index are defined for each critical section. Finally, the lateral seismic fragility of the components and system of CSB was carried out. Based on the result of probabilistic estimation of lateral seismic responses, the order of the damage probability in all four damage states for each component of bridge is given. The fragility curves of bridge system on the lower bound and upper bound are studied. Moreover, the system fragility of the entire bridge is compared with that of each component.

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