Performance‐Based Seismic Fragility and Residual Seismic Resistance Study of a Long‐Span Suspension Bridge

Self Cite

Earthquakes can cause serious damage to traffic infrastructures, among which the impact on bridge structure is the most important. Therefore, in order to assess bridges serviceability, it is important to master their damage mechanism and to analyze its probability of occurrence under a given seismic action. Various uncertainties, like the location of epicentre of future earthquakes and their magnitudes, make this task quite challenging. We are also required to consider different earthquake scenarios and the damaged states of bridge components associated with those earthquakes. To suppress these difficulties, this study proposed a new method of performance-based seismic fragility and risk assessment for bridges. The proposed method included three steps: (1) performance-based seismic fragility estimation of a five-span continuous rigid frame bridge, (2) seismic hazard analysis for locations of the bridge, and (3) seismic risk analysis of the bridge. The proposed method that considered the performance of the bridge and the uncertainty in the location of the earthquake epicentre and magnitudes can provide valuable references for seismic-resistant design of multispan continuous rigid frame bridges in the future.

Section: Damage Quantification Of the Bridge Pier Sectionmentioning

confidence: 99%

Performance‐Based Seismic Fragility and Risk Assessment of Five‐Span Continuous Rigid Frame Bridges

Zhou

Zhao

et al. 2021

Self Cite

“…Te most common method to improve the seismic performance of the continuous girder bridges is by installing multiple isolation devices. Researchers have performed substantial research on installing isolation bearings and viscous dampers for continuous beam bridges and obtained considerable research results [2][3][4][5][6][7][8]. Kelly and Eidinger [9] and Kelly [10] proposed the system theory and design method of laminated rubber bearing and performed tensile test research on their approach.…”

Section: Introductionmentioning

confidence: 99%

Seismic Reduction Performance of Wrap Rope Connection Devices for Continuous Girder Bridges

Liu

Zhang

et al. 2023

In this article, wrap rope connection device (WRCD), which considers the relative acceleration of piers and beam as a control variable, is proposed for improving the current situation of continuous girder bridges whose bearing force of a single pier is along the longitudinal direction and based on the synergy principle. The WRCD device, which meets the slow displacement requirements of temperature and vehicle load under normal operation, is implemented and used to improve the performance of the sliding bearing pier. During earthquakes, because of the amplification effect of the wrap rope, the instantaneous large stiffness state in the longitudinal force can be achieved. Based on the shaking table test of a typical continuous girder bridge for examining the performance of the WRCD during earthquakes, the dynamic characteristics, structural acceleration, displacement, and strain responses of the structure under different frequency spectra, and seismic input intensities are analyzed and the seismic reduction performance of the WRCD is demonstrated. This analysis demonstrated that, by activating WRCD, the ratio of the acceleration response of the fixed bearing pier to the sliding bearing pier increased from 10% to 57%; moreover, the force on each pier appeared more uniform. Furthermore, with an increase in the input intensity of the earthquake, the displacement of the primary beam and the seismic response of the fixed pier bottom considerably decreased and the synergy effect of each pier was more prominent. Under certain site conditions, the WRCD can effectively improve the synergy effect between the sliding bearing piers and fixed bearing pier; however, the improvement in the obtained result is directly associated with the seismic input characteristics. The design parameters of the WRCD should be determined as per different site conditions and the optimum application range of the WRCD.

“…However, regardless of the type of isolation bearings adopted, a large relative displacement must be applied to accomplish the ideal damping e ect [4,5]. In recent years, sure researchers have conducted systematic studies on lock-up devices; then, lock-up connections cannot e ectively reduce the impact of seismic activity on low-pier continuous-girder bridges [6][7][8][9][10]. Moreover, owing to cost and late maintenance, there are not many applications in practical engineering.…”

Section: Introductionmentioning

confidence: 99%

Shaking Table Tests on Wrap Rope Connect Device for Continuous‐Beam Bridges with Different Pier Heights

Liu

Zhang

et al. 2022

To investigate the cooperative and isolation effectiveness of the wrapped rope connect device (WRCD) on continuous-beam bridges with different pier heights, shaking table tests were conducted on a typical three-span continuous-beam bridge model. The model had additional pier stiffness and applied the WRCD. Two actual seismic waves with different spectral characteristics and multiple intensities were used for input ground motion. By examining the performance and measured structural response under various excitations, WRCD could effectively improve the overall cooperative effect of the model structure for a limited increase in the input seismic energy of the system. The acceleration ratio from the fixed pier top to the movable pier top increased from∼17% without the WRCD to∼32% with it. The strain-response ratio of the pier bottom decreased from its maximum of 24.8 times to 3.6 times after the device was applied. There is a specific relationship between the influence and the pier height of the structure, and the rules for high and low piers slightly differ. The movable and fixed ports can be coordinated by setting reasonable design parameters of the WRCD, which can be used for the seismic design of continuous-beam bridges with different pier heights.