Vulnerability and optimal probabilistic seismic demand model for curved and skewed RC bridges

2018 ◽  
Vol 176 ◽  
pp. 411-425 ◽  
Author(s):  
Nina Serdar ◽  
Radomir Folić
Keyword(s):  
Seismic Demand ◽  
Demand Model ◽  
Probabilistic Seismic Demand ◽  
Seismic Demand Model

scholarly journals Fragility Analyses of Bridge Structures Using the Logarithmic Piecewise Function-Based Probabilistic Seismic Demand Model

2021 ◽  
Vol 13 (14) ◽  
pp. 7814
Author(s):  
Yinghao Zhao ◽  
Hesong Hu ◽  
Lunhua Bai ◽  
Mengxiong Tang ◽  
Hang Chen ◽  
...  
Keyword(s):  
Fragility Curves ◽  
Statistical Significance ◽  
Seismic Intensity ◽  
Fragility Analysis ◽  
Seismic Demand ◽  
Demand Model ◽  
Intensity Measure ◽  
System Fragility ◽  
Probabilistic Seismic Demand ◽  
Seismic Demand Model

Seismic fragility analysis is an efficient method to evaluate the structural failure probability during earthquake events. Among the existing fragility analysis methods, the probabilistic seismic demand model (PSDM) and the joint probabilistic seismic demand model (JPSDM) are generally used to compute the component and system fragility, respectively. However, the statistical significance behind the parameters related to the current PSDM and JPSDM are not comparable. Aside from that, when calculating the system fragility, the Monte Carlo sampling (MCS) method is time-consuming. To solve the two flaws, in this paper, the logarithm piecewise functions were used to generate the PSDM and the JPSDM, and the MCS was replaced by the univariate conditioning approximation (UCA) method. The concepts and application procedures of the proposed fragility analysis methods were elaborated first. Then, the UCA method was illustrated in detail. Finally, fragility curves of a steel arch truss case study bridge were generated by the proposed method. The research results indicate the following: (1) the proposed methods unify the data sources and statistical significance of the parameters used in the PSDM and the JPSDM; (2) the logarithmic piecewise function-based PSDM sensitively reflects the changing trend of the component’s demand with the fluctuation of the seismic intensity measure; (3) under transverse seismic waves, major injuries happen on the side bearings of the bridge, while slight damage may occur on each pier, and as the seismic intensity measure increases, the side bearings are more likely to be damaged; (4) for the severe damage and the absolute damage of the studied bridge, the system fragility curves are closer to the upper failure bounds; and (5) compared with the MSC method, the accuracy of the UCA method can be guaranteed with less calculation time.

A Probabilistic Seismic Demand Model for Regular Highway Bridges

2016 ◽  
Vol 847 ◽  
pp. 307-318 ◽  
Author(s):  
Hai Bin Ma ◽  
Wei Dong Zhuo ◽  
Gu Yin ◽  
Ying Sun ◽  
Li Bo Chen
Keyword(s):  
Probability Distributions ◽  
Highway Bridges ◽  
Seismic Demand ◽  
Site Conditions ◽  
Demand Model ◽  
Demand Models ◽  
Probabilistic Seismic Demand ◽  
Performance Based Seismic Design ◽  
Seismic Demand Model ◽  
And Performance

Probabilistic seismic demand models are important for the design of structures based on the seismic probability and the performance of the structure. In this paper, the probabilistic seismic demands of 8 representative regular highway bridges are calculated using the cloud approach by selecting 2390 earthquake records for 3 different site conditions. These demands are expressed in terms of an intensity measure (IM), which is the spectral acceleration at the fundamental period with 5% damping, and an engineering demand parameter (EDP), which is the drift ratio at the top of pier. The probability distributions of the EDP are established at several IM levels. The results show that the EDPs have reasonably standard beta distributions at different IM levels. A correlation between the mean EDP and the IM is also established using regression analysis. The probabilistic seismic demand model is suitable for 3 different site conditions and can greatly simplify the calculation of seismic demand in the probability-based and performance-based seismic design of regular bridges.

Sign in / Sign up

Export Citation Format

Share Document