1. Structural health monitoring for performance assessment of bridges under flooding and seismic actionsLuke J. Prendergast, Maria P. Limongelli, Naida Ademovic, Andrej Anžlin, Gavin Kenneth, Mariano Zanini, 2018, original scientific article Abstract: Bridges can be subjected to damaging environmental actions due to flooding and seismic hazards. Flood actions that result in scour are a leading cause of bridge failure, while seismic actions that induce lateral forces may lead to high ductility demand that exceeds pier capacity. When combined, seismic actions and scour can lead to effects that depend on the governing scour condition affecting a bridge. Loss of stiffness under scour can reduce the ductility capacity of a bridge but can also lead to an increase in flexibility that may reduce seismic inertial forces. Conversely, increased flexibility can lead to deck collapse due to support loss, so there exists some uncertainty about the combined effect of both phenomena. A necessary step towards the performance assessment of bridges under flooding and seismic actions is to calibrate numerical models that can reproduce structural responses under different actions. A further step is verifying the achievement of performance goals defined by codes. Structural health monitoring (SHM) techniques allow the computation of performance parameters that are useful for calibrating numerical models and performing direct checks of performance goal compliance. In this paper, various strategies employed to monitor bridge health against scour and seismic actions are discussed, with a particular focus on vibration-based damage identification methods. Keywords: scour, seismic, damage, hazard, vibration-based methods Published in DiRROS: 29.11.2023; Views: 429; Downloads: 212
Full text (2,18 MB) This document has many files! More... |
2. Flood vulnerability study of a roadway bridge subjected to hydrodynamic actions, local scour and wood debris accumulationMirko Kosič, Andrej Anžlin, Valentina Bau', 2022, original scientific article Abstract: 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. Keywords: flooding, vulnerability, wood debris, local scour, hydrodynamic load, stochastic approach, bridges, open access Published in DiRROS: 31.05.2023; Views: 562; Downloads: 301
Full text (7,59 MB) This document has many files! More... |
3. Analysis of the response of a roadway bridge under extreme flooding-related events: Scour and debris-loadingMirko Kosič, Luke J. Prendergast, Andrej Anžlin, 2023, original scientific article Abstract: 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. Keywords: local scour, wood debris, flooding, resilience, soil-structure interaction, bridges, open access Published in DiRROS: 29.05.2023; Views: 516; Downloads: 418
Full text (4,32 MB) This document has many files! More... |