A simplified method to estimate the fundamental frequency of skew continuous multicell box-girder bridges

Mohseni, Iman; Rashid, Abdul; Kang, Junsunk

doi:10.1590/s1679-78252014000400006

Cited by 10 publications

(4 citation statements)

References 17 publications

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“…Recent studies have shown that expansion joints are one of the main causes of many defects in bridges. With an increase in gap width, the impact and possible damage are potentially more serious [17].…”

Section: Discussionmentioning

confidence: 99%

Bridge Safety Analysis Based on the Function of Exceptional Vehicle Transit Speed

Ventura¹,

Barabino²,

Vetturi³

et al. 2020

TOTJ

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Background: The road management agencies often prescribe very low-speed limits for exceptional vehicles transiting on the deck. These restrictions aim to reduce the dynamic effects due to the vehicle-bridge interaction because it is assumed that these effects increase with speed. However, sometimes, a reduction in speed increases the encounter probability of two exceptional vehicles travelling in opposite directions and this could compromise the safety of the bridge when the total masses of both vehicles exceed the bridge bearing capacity (or limit mass). Objective: While the literature has investigated the encounter probability in a theoretical way and has investigated the vehicle-bridge interaction, especially in terms of dynamic load increment, to the best of our knowledge, no study has investigated the conjunction probability of encounters and of exceeding the limit mass also by using real data. This paper aims to cover this gap by proposing an integrated model that computes the “Annual Probability of Failure” of the bridge, defined as the likelihood to exceed the “Limit Mass" of the deck when two opposite exceptional vehicles encounter. Methods: According to the probability theory, the “Annual Probability of Failure” can be obtained by multiplying the likelihood that during the reference year, at least once, two exceptional vehicles, travelling in two opposite directions (ascendant and descendant), will be simultaneously on the bridge deck (“Annual probability of encounter”) with the likelihood that the sum of the single masses of two exceptional vehicles randomly extracted from the sample, including the dynamic effects, exceeds the limit mass ml (“Probability of exceeding the limit mass”). Results: The results show that the probability of encounter increases with both the exceptional vehicles flow rate and the length of the span, whereas it decreases with the passing speed. The probability of exceeding the limit mass increases with speed. Nevertheless, by combining both the probabilities, these results suggest the existence of an “Optimal Speed”, which minimizes the “Annual Probability of Failure”. Conclusion: The existence of an “Optimal Speed” should be considered when defining the exceptional vehicle transit rules on bridges as well as the speed limit.

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Section: Discussionmentioning

confidence: 99%

Bridge Safety Analysis Based on the Function of Exceptional Vehicle Transit Speed

Ventura¹,

Barabino²,

Vetturi³

et al. 2020

TOTJ

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“…According to the Federal Highway Administration national bridge inventory, over 25% of US bridges have maximum spans between 15 and 50 m 53 . It is difficult to establish expected values for the fundamental frequencies of such bridges; however, they can be considered greater than 1 Hz 54,55 and are therefore more likely to coincide with vehicle modal frequencies, which usually range 1-3 Hz 56,57 .…”

Section: Number Of Vehicle Trips Versus Accuracymentioning

confidence: 99%

Crowdsourcing bridge dynamic monitoring with smartphone vehicle trips

Matarazzo

Kondor

Milardo³

et al. 2022

Commun Eng

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Monitoring and managing the structural health of bridges requires expensive specialized sensor networks. In the past decade, researchers predicted that cheap ubiquitous mobile sensors would revolutionize infrastructure maintenance; yet extracting useful information in the field with sufficient precision remains challenging. Herein we report the accurate determination of critical physical properties, modal frequencies, of two real bridges from everyday vehicle trip data. We collected smartphone data from controlled field experiments and uncontrolled Uber rides on a long-span suspension bridge in the USA (The Golden Gate Bridge) and developed an analytical method to accurately recover modal properties. We also successfully applied the method to partially-controlled crowdsourced data collected on a short-span highway bridge in Italy. Further analysis projected that the inclusion of crowdsourced data in a maintenance plan for a new bridge could add over fourteen years of service (30% increase) without additional costs. Our results suggest that massive and inexpensive datasets collected by smartphones could play a role in monitoring the health of existing transportation infrastructure.

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“…A new analytical method is proposed to determine the natural frequencies and the mode shapes of the multi-span bridge and compared the results with the numerical results obtained by ANSYS [8]. The effect of the span, number of cells, and skew angle on a box-girder bridge's fundamental frequency are investigated using SAP2000 [9]. The static analysis is performed on skew-curved box-girder bridge experimentally [10].…”

Section: Introductionmentioning

confidence: 99%

Free Vibration Analysis of RC Box-Girder Bridges Using FEM

Agarwal¹,

Pal²,

Mehta³

2022

Sound&Vibration

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The free vibration analysis of simply supported box-girder bridges is carried out using the finite element method. The fundamental frequency is determined in straight, skew, curved and skew-curved box-girder bridges. It is important to analyse the combined effect of skewness and curvature because skew-curved box-girder bridge behaviour cannot be predicted by simply adding the individual effects of skewness and curvature. At first, an existing model is considered to validate the present approach. A convergence study is carried out to decide the mesh size in the finite element method. An exhaustive parametric study is conducted to determine the fundamental frequency of box-girder bridges with varying skew angle, curve angle, span, span-depth ratio and cell number. The skew angle is varied from 0°to 60°, curve angle is varied from 0°to 60°, span is changed from 25 to 50 m, span-depth ratio is varied from 10 to 16, and single cell & double cell are used in the present study. A total of 420 bridge models are used for parametric study in the investigation. Mode shapes of the skew-curved bridge are also presented. The fundamental frequency of the skew-curved box-girder bridge is found to be more than the straight bridge, so, the skew-curved box-girder bridge is preferable. The present study may be useful in the design of box-girder bridges.

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A simplified method to estimate the fundamental frequency of skew continuous multicell box-girder bridges

Cited by 10 publications

References 17 publications

Bridge Safety Analysis Based on the Function of Exceptional Vehicle Transit Speed

Bridge Safety Analysis Based on the Function of Exceptional Vehicle Transit Speed

Crowdsourcing bridge dynamic monitoring with smartphone vehicle trips

Free Vibration Analysis of RC Box-Girder Bridges Using FEM

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