System Fragility Analysis of a Cable-Stayed Bridge Using Cable Sliding Friction Aseismic Bearings Under Spatially Varying Excitations

2018 ◽  
Author(s):  
Kai Ma ◽  
Wancheng Yuan ◽  
Xinzhi Dang
Keyword(s):  
Sliding Friction ◽  
Fragility Analysis ◽  
Cable Stayed Bridge ◽  
System Fragility ◽  
Spatially Varying

An endurance time method-based fragility analysis framework for cable-stayed bridge systems under scour and earthquake

2021 ◽  
Vol 232 ◽  
pp. 109128
Author(s):  
Kai Wei ◽  
Haifeng He ◽  
Jiarui Zhang ◽  
Cancan Yang ◽  
Shunquan Qin
Keyword(s):  
Fragility Analysis ◽  
Analysis Framework ◽  
Endurance Time ◽  
Cable Stayed Bridge ◽  
Endurance Time Method

scholarly journals Seismic Fragility Analysis of Multispan Reinforced Concrete Bridges Using Mainshock-Aftershock Sequences

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yutao Pang ◽  
Li Wu
Keyword(s):  
Reinforced Concrete ◽  
Earthquake Engineering ◽  
Design Method ◽  
Fragility Curves ◽  
Uniform Design ◽  
Time History ◽  
Fragility Analysis ◽  
Nonlinear Time History Analysis ◽  
Aftershock Sequences ◽  
System Fragility

Although the knowledge and technology of performance-based earthquake engineering have rapidly advanced in the past several decades, current seismic design codes simply ignore the effect of aftershocks on the performance of structures. Thus, the present paper investigated the effect of aftershocks on seismic responses of multispan reinforced concrete (RC) bridges using the fragility-based numerical approach. For that purpose, a continuous girder RC bridge class containing 8 bridges was selected based on the statistical analysis of the existing RC bridges in China. 75 recorded mainshock-aftershock seismic sequences from 10 well-known earthquakes were selected in this study. In order to account for the uncertainty of modeling parameters, uniform design method was applied as the sampling method for generating the samples for fragility analysis. Fragility curves were then developed using nonlinear time-history analysis in terms of the peak curvature of pier column and displacement of bearings. Finally, the system fragility curves were derived by implementing Monte Carlo simulation on multinormal distribution of two components. From the results of this investigation, it was found that, for the RC continuous bridges, the influence of aftershocks can be harmful to both bridge components and system, which increases both the component fragility of the displacement of bearings and seismic curvature of pier sections and system fragility.

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.

scholarly journals Effects of fault finiteness on near-source ground motion

1981 ◽  
Vol 71 (4) ◽  
pp. 939-957
Author(s):  
Ralph J. Archuleta ◽  
Stephen H. Hartzell
Keyword(s):  
Ground Motion ◽  
Wave Speed ◽  
Sliding Friction ◽  
Ground Motions ◽  
Vertical Component ◽  
Displacement Function ◽  
Rupture Velocity ◽  
Maximum Acceleration ◽  
Shear Wave Speed ◽  
Spatially Varying

abstract Near-source ground motion at four azimuths but constant epicentral range is computed from a buried circular strike-slip fault in a half-space. Particle acceleration, velocity, and displacement at each station on the free surface is computed in the frequency band 0.0 to 5.0 Hz. The assumed dislocation is derived from the Kostrov (1964) displacement function for a continuously propagating stress relaxation. The azimuthal variations in the amplitudes and waveforms directly result from spatially varying slip on the fault, spatially varying radiation pattern over the fault, and the magnitude and direction of the rupture velocity. The near-source ground motions are dominated by the rupture in the direction of the receiver. Using a 100-bar effective stress (initial stress minus sliding friction) in a Poisson solid with β = 3.0 km/sec the shear wave speed, and shear modulus μ = 3.0 × 1011 dyne/cm2, the simulated earthquake has a moment Mo = 4.5 × 1025 dyne-cm. Using a rupture velocity of 0.9β, the peak acceleration is 1195 cm/sec2 and velocity 104 cm/sec for the receiver directly on strike. For a receiver 30° off strike, the maximum acceleration 236 cm/sec2 occurs on the vertical component.

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