scholarly journals Shake Table Test of Long Span Cable-Stayed Bridge Subjected to Near-Fault Ground Motions Considering Velocity Pulse Effect and Non-Uniform Excitation

2020 ◽  
Vol 10 (19) ◽  
pp. 6969
Author(s):  
Chao Zhang ◽  
Guanghui Fu ◽  
Zhichao Lai ◽  
Xiuli Du ◽  
Piguang Wang ◽  
...  
Keyword(s):  
Ground Motions ◽  
Near Field ◽  
Shake Table ◽  
Velocity Pulse ◽  
Maximum Displacement ◽  
Maximum Acceleration ◽  
Shake Table Tests ◽  
Near Fault ◽  
Cable Stayed Bridge ◽  
Long Span

This paper presents the results of shake table tests of a scaled long span cable-stayed bridge (CSB). The design principles of the scaled CSB are first introduced. The first six in-plane modes are then identified by the stochastic subspace identification (SSI) method. Furthermore, shake table tests of the CSB subjected to the non-pulse near-field (NNF) and velocity-pulse near-fault (PNF) ground motions are carried out. The tests indicated that: (1) the responses under longitudinal uniform excitation are mainly contributed by antisymmetric modes; (2) the maximum displacement of the tower occurs on the tower top node, the maximum acceleration response of the tower occurs on the middle cross beam, and the maximum bending moment of the tower occurs on the bottom section; (3) the deformation of the tower and girder subjected to uniform excitation is not always larger than that subjected to non-uniform excitation, and therefore the non-uniform case should be considered in the seismic design of CSBs.

Seismic Response Analysis of the Numerical Simulation Method on Cable-Stayed Bridge Tower which Considers the Rigid Foundation

2014 ◽  
Vol 875-877 ◽  
pp. 998-1002
Author(s):  
Wei Bing Luo ◽  
Ji Ming Fan ◽  
Ji Lv ◽  
Li Ya Zhang ◽  
Cui Cui Wu
Keyword(s):  
Seismic Response ◽  
Ground Motions ◽  
Simulation Method ◽  
Response Analysis ◽  
Rigid Foundation ◽  
Seismic Responses ◽  
Near Fault ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Bridge Tower

The seismic responses under the action of far-fault and near-fault ground motions of the bridge tower structure of the long-span cable-stayed bridge are numerically discussed by means of the model of the bottom consolidation of the column. The results show that the responses of tower of the cable-stayed bridge correlate well with the properties of the ground motions. The seismic responses of the model have much larger values under the near-fault velocity pulse-like ground motions than those of the counterpart. The frequency of system reduces as the flexibility of structure decreases because of the rigid foundation; The displace response of tower shows that the rigid foundation has little influence on the seismic response of the cable-stayed bridge, while the acceleration response of the tower implies that rigid foundation has adverse effect. Thus, consideration of the soil-pile-superstructure interaction can be meaningful both in theory and reality during the seismic design of long-span cable-stayed bridge structure.

Identification of Near-Field Pulse-Like Ground Motions Recorded at Bajiao Station during the Mainshock of the Great Wenchuan Earthquake

2011 ◽  
Vol 250-253 ◽  
pp. 2546-2553 ◽  
Author(s):  
Chun Feng Li ◽  
Yong Bo Li
Keyword(s):  
Wenchuan Earthquake ◽  
Ground Motion ◽  
Strong Ground Motion ◽  
Ground Motions ◽  
Near Field ◽  
Velocity Pulse ◽  
Field Pulse ◽  
Near Fault ◽  
Ground Motion Records ◽  
Strong Ground

When earthquake occurs, it is in near-fault that the most serious damage happens and velocity pulse appears. Velocity pulse could have huge potential to destroy the structure in near-fault. The set of records at Bajiao Station is one of the three famous near-field sets of strong ground motion records whose PGAs are the largest in all the sets of records obtained from the mainshock of the Great Wenchuan Earthquake. Our research is to identify the pulse-like characteristics from the set of records at Bajiao Station. It is found that velocity pulses in the records are “hidden pulses”.

Effects of hysteretic models on the seismic evaluation of a collapsed irregular building from bidirectional near-fault ground motions on a shake table

2021 ◽  
Vol 247 ◽  
pp. 113087
Author(s):  
Jui-Liang Lin ◽  
Wen-Hui Chen ◽  
Fu-Pei Hsiao ◽  
Yuan-Tao Weng ◽  
Wen-Cheng Shen ◽  
...  
Keyword(s):  
Ground Motions ◽  
Shake Table ◽  
Seismic Evaluation ◽  
Near Fault

Conditional Ground-Motion Model for Damaging Characteristics of Near-Fault Ground Motions Based on Instantaneous Power

2020 ◽  
Vol 110 (6) ◽  
pp. 2828-2842
Author(s):  
Esra Zengin ◽  
Norman Abrahamson
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Accurate Estimation ◽  
Spectral Acceleration ◽  
Motion Model ◽  
Velocity Pulse ◽  
Near Fault ◽  
Instantaneous Power ◽  
Ground Motion Model ◽  
Short Time

ABSTRACT The velocity pulse in near-fault ground motions has been used as a key characteristic of damaging ground motions. Characterization of the velocity pulse involves three parameters: presence of the pulse, period of the pulse, and amplitude of the pulse. The basic concept behind the velocity pulse is that a large amount of seismic energy is packed into a short time, leading to larger demands on the structure. An intensity measure for near-fault ground motions, which is a direct measure of the amount of energy arriving in short time, called instantaneous power (IP (T1)), is defined as the maximum power of the bandpass-filtered velocity time series measured over a time interval of 0.5T1, in which T1 is the fundamental period of the structure. The records are bandpass filtered in the period band (0.2T1−3T1) to remove the frequencies that are not expected to excite the structure. Zengin and Abrahamson (2020) showed that the drift is better correlated with the IP (T1) than with the velocity pulse parameters for records scaled to the same spectral acceleration at T1. A conditional ground-motion model (GMM) for the IP is developed based on the 5%-damped spectral acceleration at T1, the earthquake magnitude, and the rupture distance. This conditional GMM can be used for record selection for near-fault ground motions that captures the key features of velocity pulses and can lead to a better representation of the median and variability of the maximum interstory drift. The conditional GMM can also be used in a vector hazard analysis for spectral acceleration (T1) and IP (T1) that can be used for more accurate estimation of drift hazard and seismic risk.

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