Assessing Dynamic Load Allowance of the Negative Bending Moment in Continuous Girder Bridges by Weighted Average Method

Wang, Yelu; Tian, Jie; Zhou, Yuegui; Zhao, Yu; Feng, Wei; Mao, Keqiang

doi:10.3390/coatings12091233

Cited by 3 publications

(3 citation statements)

References 40 publications

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“…The vehicle crossed the bridge with an unevenness of grade C at a constant speed of 72 km/h. The dynamic displacements of the girder and SWSS are obtained by vehicle-bridge interaction (VBI) [56], and then the DLAs are calculated by Equation (9). The dynamic displacements of the SWSS are determined by the vertical dynamic displacement of the material mass point in the system.…”

Section: Dynamic Responses and Dlasmentioning

confidence: 99%

Dynamic Deflection Measurement on Stiff Bridges with High Piers by Preloaded Spring Method

Wang,

Zhou,

Jiang

et al. 2024

Applied Sciences

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The deflection dynamic load allowance (DLA) of stiff bridges with high piers requires sub-millimeter accuracy. New technologies such as the vision-based optical method and GNSS are not yet recognized for use in DLA measurements due to their smaller SNR. Presently, the scaffolding method is widely utilized for dynamic deflection measurements in dynamic load tests owing to the reliability of employing rigid contact. When scaffolding is not available, engineers have to resort to a suspension hammer system. However, the mass eccentricity of the hammer, stretched-wire length, and wind will decrease the measurement accuracy. To overcome these drawbacks of the suspension hammer method (SHM), a preloaded spring method (PSM) and the related stretched-wire-spring system (SWSS) are proposed in this paper. The dynamic deflection of the coupled vehicle-bridge-SWSS was obtained by vehicle-bridge interaction (VBI) analysis. The sensitivity parameters of the PSM were analyzed and optimized to minimize the measurement error. Indoor experiments and field dynamic load tests were conducted to validate the feasibility and accuracy of the PSM. Additionally, the differences in dynamic deflection measurements between the PSM and SHM in windy environments were compared. The results show that, in a windless environment, the DLAs of the PSM are affected by the spring stiffness, stretched-wire length, and stretched-wire section stiffness, independently of the preload force. When the wind speed is less than or equal to 8 m/s and the pier height is less than 30 m, the maximum deflection measurement error of the PSM is −2.53%, while that of the SHM is −15.87%. Due to its low cost and high accuracy, the proposed method has broad application prospects in the dynamic deflection measurement of stiff bridges with high piers.

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Section: Dynamic Responses and Dlasmentioning

confidence: 99%

Dynamic Deflection Measurement on Stiff Bridges with High Piers by Preloaded Spring Method

Wang,

Zhou,

Jiang

et al. 2024

Applied Sciences

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“…At a speed of 120 km/h, the dynamic response amplitude of the bridge reaches its maximum value. Studies have shown that the influence of vehicle speed on the dynamic response of bridges is relatively complex and may work in conjunction with various other factors to affect the vibration response of the bridge [36].…”

Section: Vehicle Speedmentioning

confidence: 99%

Dynamic Response Analysis of Long-Span Bridges under Random Traffic Flow Based on Sieving Method

Han,

Xie,

Zhou

et al. 2023

Buildings

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To overcome the limitations of using time interval division to calculate the bridge impact coefficient (IM), a sieving method has been proposed. This method employs multiple sieves on bridge time–history curve samples to ultimately obtain the bridge impact coefficients. Firstly, CA cellular automata are used to establish different levels of traffic flow fleet models. The random traffic flow–bridge coupling dynamic model is established through wheel–bridge displacement coordination and mechanical coupling relationships based on the theory of modal synthesis. Then, the variation of bridge dynamic time–history curves for different classes of random traffic flow, speed and pavement unevenness parameters are analyzed. The sieving method is applied to screen the extreme points of the dynamic time–history curve of the bridge, enabling the distribution law of the bridge IM to be obtained using the Kolmogorov–Smirnov test (K–S test) and statistical analysis. Finally, the calculated value is then compared with the IM specifications of multiple countries. The results show that the proposed method has high identification accuracy and produces a good inspection effect. The value obtained using the sieving method is slightly larger than the value specified in the US code, 0.33, which is considerably larger than the values specified in other national codes. As pavement conditions deteriorate, the IM of the bridge increases rapidly, especially under Class C and Class D pavement unevenness, which exceed the values specified in various national bridge specifications.

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“…Similar findings were also reported by other researchers [ 22 , 25 , 26 , 27 ]. In dynamic load tests, the acquired signals are usually filtered and de-noised, resulting in the removal of higher-order signals [ 16 , 28 ]. Currently, there is no consensus on the cut-off modes for calculating the DAFs of continuous girder bridges [ 29 ].…”

Section: Introductionmentioning

confidence: 99%

Comparison of Dynamic Amplification Factor of Deflection and Bending Moment of Highway Continuous Box-Girder Bridges by Mode Superposition

Wang,

Zhou,

Zhao

et al. 2024

Materials

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There are differences between the dynamic deflection and bending moment (strain) in the same section of continuous girder bridges. However, the selection of the response for calculating dynamic amplification factors (DAFs), which are essential for bridge health monitoring and safety assessment, remains controversial. Modes may play a role in the relationship between the deflection DAF and the bending moment DAF in both numerical analysis and field tests. To investigate the distinctions between the DAFs of the deflection and bending moment in a continuous girder bridge, functional expressions of the DAFs were derived, taking into account multi-factor coupling under concentrated forces. The interaction effects of the mode and road surface condition (RSC), vehicle speed, bridge span length, and span number on the deflection DAF, the bending moment DAF, and the ratio of the deflection DAF to the bending moment DAF (RDM) of precast continuous box-girder bridges were analyzed using vehicle-bridge interaction. To ensure the accuracy of the DAF in numerical computations and experimental tests, two types of accuracy indexes and the corresponding cut-off modes were provided. Validation was conducted by performing dynamic load tests on two field bridges. The results indicate that different modes have a significant effect on the RDM of the mid-span section of a bridge. When considering multiple factors, the deflection DAF and bending moment DAF of the mid-span section increased rapidly with the considered modes and then stabilized. Statistically, the RDM of all nine bridges ranged from 1.00 to 1.12, indicating that the deflection DAF was greater than the bending moment DAF. The suggested cut-off modes can be utilized for efficient and accurate calculation of the DAF and response signal fidelity.

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Assessing Dynamic Load Allowance of the Negative Bending Moment in Continuous Girder Bridges by Weighted Average Method

Cited by 3 publications

References 40 publications

Dynamic Deflection Measurement on Stiff Bridges with High Piers by Preloaded Spring Method

Dynamic Deflection Measurement on Stiff Bridges with High Piers by Preloaded Spring Method

Dynamic Response Analysis of Long-Span Bridges under Random Traffic Flow Based on Sieving Method

Comparison of Dynamic Amplification Factor of Deflection and Bending Moment of Highway Continuous Box-Girder Bridges by Mode Superposition

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