1. A practical method to incorporate scour hole shape effects in Winkler-type pile foundation models for bridgesMirko Kosič, Luke J. Prendergast, Andrej Anžlin, 2025, izvirni znanstveni članek Povzetek: Scour erosion continues to cause significant issues for the stability and lifespan of bridges worldwide. In Slovenia, extreme flooding in 2023 caused the collapse or failure of many bridges, primarily due to scour, which was exacerbated by debris accumulation. Despite advances in predicting and monitoring scour, it remains among the top reasons for the failure of bridges during flooding. Recent advances in vibration-based health monitoring suggest that scour erosion can be detected using methods such as changes in natural frequency, mode shapes, flexibility-based deflection, and other approaches using offline sensors such as passing vehicle responses. Many of these methods have been trialled numerically where scour is implemented as a reduction in the soil level (or stiffness) around a given bridge foundation. The most common way to model scour is to lower the soil level around a foundation, however, this ignores any contribution that the scour hole shape makes to the stiffness and strength of the soil beneath the scour hole. This paper investigates how the shape of scour holes influences the stiffness and strength of the remaining soil to understand the impact on the modal behaviour of a bridge. A numerical model of a bridge is developed where scour is implemented by removing Winkler springs from the model, and different scour hole shapes are considered in terms of how the remaining overburden influences the stiffness and strength of the soil springs. Scour hole shape properties are considered by means of varying the depth, width, and slope angle of the hole around a given foundation element. For the analyses in this paper, different scour hole shapes are implemented on an example bridge corresponding to local scour holes with narrow width; wider local scour holes; and general scour, where the full soil layer is removed (infinite width). The changes in the modal periods and mode shapes of the bridge in the traffic and river flow directions are assessed to understand the impact of the different scour types on the vibration characteristics.
Ključne besede: scour, dynamics, overburden, frequency, damage, bridges, scour hole shape
Objavljeno v DiRROS: 13.01.2026; Ogledov: 236; Prenosov: 181
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2. oVERFLOw project : Vulnerability assessment of embankments and bridges exposed to flooding hazards : Deliverable 6.4Valentina Bau', Mirko Kosič, Andrej Anžlin, Mario Bacic, 2022, končno poročilo o rezultatih raziskav Povzetek: This deliverable is a report on the development of a strategy for adaptation measures to flood events for the embankments, riverbanks and bridges, which can afterwards be used for the case study areas considered in the Overflow project. The deliverable presents a comprehensive approach that enables the choice of the best adaptation measures to overcome the vulnerability of critical infrastructure to flooding events. The most suitable countermeasures can therefore be selected based on the outcomes of the vulnerability assessment and risk forecasting tool. Such a strategy will be essential for the relevant authorities and IMs. The strategy proposes optimal adaptation measures depending on areas specificities, incorporating socio-economic and environmental multi-objective optimization.
Ključne besede: adaptation measures, countermeasures, vulnerability, flooding, resilience, embankments, bridges
Objavljeno v DiRROS: 29.07.2024; Ogledov: 1288; Prenosov: 489
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3. Modelling of traffic load effects in the assessment of existing road bridgesDominik Skokandić, Ana Mandić Ivanković, Aleš Žnidarič, Mladen Srbić, 2019, pregledni znanstveni članek Povzetek: Traffic load models used for the design of new bridges are based on conservative assumptions and have not been proven efficient for assessing safety of existing bridges. In the case of existing bridges, it is reasonable to use load models that are based on bridge weigh-in-motion data which, in addition to axle loads and spacing of bridge-crossing vehicles, provide information on bridge behaviour under traffic load. This paper provides an overview of traffic load models, as well as guidelines on the use of weigh-in-motion data when assessing condition of existing road bridges.
Ključne besede: prometna obtežba, tehtanje vozil med vožnjo, mostni WIM, ocenjevanje stanja, obstoječi mostovi, traffic load, weigh-in-motion, bridge WIM, condition assessment, existing bridges
Objavljeno v DiRROS: 27.03.2024; Ogledov: 1555; Prenosov: 1243
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4. Flood vulnerability study of a roadway bridge subjected to hydrodynamic actions, local scour and wood debris accumulationMirko Kosič, Andrej Anžlin, Valentina Bau', 2022, izvirni znanstveni članek Povzetek: The increased occurrence and intensity of flooding events have represented a real threat to bridge reliability and end-user safety. As flood vulnerability assessment is a valuable tool for enhancing the resilience of bridges to climate change, it is of interest to push the development of such methods. To this end, a computationally efficient methodology to assess the flood vulnerability of a bridge was developed and implemented in a case study. A particular focus was devoted to modelling wood debris loads on the bridge pier, for which two different approaches were implemented. The first is a standards-based approach, whereas the second is based on up-to-date research data. The results indicate that the second approach is less conservative as it leads up to a 40% higher exceedance probability for the considered limit states. The interaction between wood debris loads and local scour was also examined and proved to have a relevant impact on the vulnerability of the bridge. These results highlight the shortcomings of the existing standards in providing accurate results. It is perceived that not only will the new quantitative tool be valuable in ensuring optimal bridge design, but it will also be beneficial for assessing bridge risk mitigation measures.
Ključne besede: flooding, vulnerability, wood debris, local scour, hydrodynamic load, stochastic approach, bridges, open access
Objavljeno v DiRROS: 31.05.2023; Ogledov: 1834; Prenosov: 971
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5. Analysis of the response of a roadway bridge under extreme flooding-related events: Scour and debris-loadingMirko Kosič, Luke J. Prendergast, Andrej Anžlin, 2023, izvirni znanstveni članek Povzetek: Hydraulic actions on bridges are a leading cause of failure, especially due to the occurrence of scour erosion. Due to climate change, flooding and scour risks are exacerbating for bridges worldwide, leading to a significant stress burden on asset management agencies. Assessing structures for scour has received significant attention in recent years, however, there are few studies which investigate the influence of scour on the components of a bridge to understand how various elements interact. Moreover, the presence of debris loading, which can occur due to flooding causing debris to become lodged at structures, has not received significant attention. Debris can worsen scour conditions and increase hydraulic loading on a bridge. In this paper, an analysis of the response of various components of a roadway bridge when exposed to extreme flooding is conducted. The influence of scour and debris on hydraulic loading, internal forces, modal periods, and utilization ratios of various bridge components is ascertained. A numerical model is developed using OpenSees employing two different methods to model the soil-structure interaction. Results for several flooding scenarios show how the various bridge elements are influenced by variations in water height and velocity, scour depth, and presence of debris.
Ključne besede: local scour, wood debris, flooding, resilience, soil-structure interaction, bridges, open access
Objavljeno v DiRROS: 29.05.2023; Ogledov: 1599; Prenosov: 1252
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