Flood fragility analysis for bridges with multiple failure modes

Abstract

Bridges are one of the most important infrastructure systems that provide public and economic bases for humankind. It is also widely known that bridges are exposed to a variety of flood-related risk factors such as bridge scour, structural deterioration, and debris accumulation, which can cause structural damage and even failure of bridges through a variety of failure modes. However, flood fragility has not received as much attention as seismic fragility despite the significant amount of damage and costs resulting from flood hazards. There have been few research efforts to estimate the flood fragility of bridges considering various flood-related factors and the corresponding failure modes. Therefore, this study proposes a new approach for bridge flood fragility analysis. To obtain accurate flood fragility estimates, reliability analysis is performed in conjunction with finite element analysis, which can sophisticatedly simulate the structural response of a bridge under a flood by accounting for flood-related risk factors. The proposed approach is applied to a numerical example of an actual bridge in Korea. Flood fragility curves accounting for multiple failure modes, including lack of pier ductility or pile ductility, pier rebar rupture, pile rupture, and deck loss, are derived and presented in this study.

Fragility of transport assets exposed to multiple hazards: State-of-the-art review toward infrastructural resilience

“…More recently, Karamlou and Bocchini (2017) proposed a methodology to develop probabilistic functionality-fragility surfaces by integrating fragility and restoration functions. Tanasic et al (2013) developed analytical fragility functions for multiple span continuous RC bridges considering degradation of the elastic and plastic soil parameters over time due to scour and Kim et al (2017) obtained flood fragility estimates for a case study bridge, considering multiple failure modes due to scour and corrosion effects to piles and steel reinforcement. Peduto et al (2018) generated empirical fragility curves for bridge settlement-induced damage in Amsterdam (Holland) using damage surveys and remote sensing measurements of settlements.…”

“…flood discharge, flow intensity, shape of the flood hydrograph etc, that are associated with the scour depth or water pressure estimation (e.g. Kim et al 2017;Tubaldi et al 2017;Yilmaz et al 2017). Vulnerability assessment of infrastructure, vehicles, and people to landslide hazards involve large uncertainties and complexities; therefore, most of the approaches are based on empirical data and expert judgment (Corominas et al 2014;Wong and Winter 2018;.…”

Development of fragility curves for road embankments exposed to perpendicular debris flows

“…Bridges have a high exposure to debris flows since they are designed to cross river sections, mostly perpendicular to the flow. The main effects of these flows on bridges result from the riverbed scouring on the foundation of piers and abutments, as well as deck sliding depending on the intensity of the event (Kim et al 2017;Dag a et al 2018;Zou et al 2018;Argyroudis et al 2019). Embankments are also affected when they are exposed to perpendicular flows passing through smaller water runoff areas, where sewers or culverts usually exist, as well as when they provide access to bridges.…”

“…Martinovi c et al (2018) proposed a methodology for developing fragility curves for rainfall induced landslides on transport networks and applied it to a typical slope case on the Irish rail network. Through a reliability and finite element analysis Kim et al (2017) developed fragility curves representing multiple types of bridge failure due to flood. Winter et al (2013Winter et al ( , 2014 developed fragility curves for roads associated with traffic disruption resulting from the deposit of debris flow material on the platform.…”

Evaluation of the risk due to fluvial flooding in vehicles and road infrastructures at basin scale

“…Scour is the most common cause of bridge failure during flooding as the removal of material from the supporting soil reduces the bearing capacity of the foundation and increases the load on the piles and abutments. (Yanmaz and Apaydin, 2012;Hung and Yau, 2017;Kim et al, 2017). Total scour is equal to the sum of general scour, localized scour and local scour (Barbetta et al, 2017).…”