Flood hazards are becoming increasingly prevalent in several countries due to multiple reasons including global climate change. Bridge failure statistics indicate that over the last couple of decades, flood-related issues such as scour, hydrodynamic forces, and debris forces have caused the maximum number of bridge failure cases worldwide in comparison with other natural hazards. Such observations clearly demonstrate the need for consistent code provisions among different codes to design highway river-crossing bridges against the growing demand
from flowing water during floods. The current study performs a comprehensive review of six international bridge design codes that provide guidelines to calculate flood-induced forces for design of bridges against flood. Following these provisions, flood loads on various components
of two bridges with different geometric configurations and material properties are estimated under a number of flood cases. Finite-element (FE) models of the bridges are developed to analyze them for estimated flood loads. The outcomes revealed that obtained bridge response following these six codes varied over a wide range. A comparative assessment among these response values demonstrated the disparity of these code provisions for flood design of bridges@en

Global bridge failure statistics highlight that hydraulic actions, particularly hydrodynamic forces and scour, contribute significantly to bridge failures. Previous incidents reveal that extreme floods can lead to complete inundation, resulting in collapse of bridges. Recent studies underscore the vulnerability of the superstructure during flood events. Despite prior research, understanding the impact of flood-induced hydraulic forces on diverse bridge components, particularly in life-cycle analysis with gradual degradation from chlorideinduced corrosion, remains limited. This study utilizes computational fluid dynamics (CFD) simulations through ANSYS Fluent. It evaluates hydrodynamic forces on superstructure of a typical RC riverine bridge, accounting for gradual performance degradation due to corrosion. The study considers flood-induced scour and conducts finite element (FE) analyses at different stages of the bridge’s lifespan, offering insights into its life-cycle performance under diverse flood scenarios. These findings inform strategies to mitigate the enhanced flood vulnerability of inland RC river bridges facing future intense flood events.

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Extreme floods can cause water level to rise above bridge superstructures. Following worldwide statistics on hydraulic bridge failure, it becomes essential to generate a comprehensive knowledge base to predict probable bridge failure scenarios under future floods and to identify appropriate countermeasures for flood risk mitigation. With this objective, the study here develops a numerical framework for systematic evaluation of forces on vulnerable bridge components during floods and to understand the global response of inland river-crossing bridges under flood hazards. Computational fluid dynamics (CFD) simulations are performed to calculate hydrodynamic forces on superstructure of a representative bridge for different inundation levels and flood velocities resulting from varied intensity flood events. Hydrodynamic forces on piers and scour depths around foundations are estimated for flood cases considered here. Knowing the forces and scour depths, finite element bridge models with and without scour are developed and analyzed to apprehend its global response and progressive failure under various combinations of water height and velocity. Further, regression relations are proposed to project component-level responses based on which damage state of the bridge under future intense flood events and fragility characteristics could be predicted. Thus, results enable identifying key factors to reduce flood vulnerability of inland bridges.@en

Riverine flood is one of the critical natural threats to river-crossing bridges. As floods are the most-occurred natural hazard worldwide, survival probability of bridges due to floods must be assessed in a speedy but precise manner. In this regard, the paper presents a reliability-based approach for a rapid assessment of failure probability of vulnerable bridge components under floods. This robust method is generic in nature and can be applied to both concrete and steel girder bridges. The developed methodology essentially utilizes limit state performance functions, expressed in terms of capacity and flood demand, for probable failure modes of various vulnerable components of bridges. Advanced First Order Reliability Method (AFORM), Monte Carlo Simulation (MCS), and Latin Hypercube Simulation (LHS) techniques are applied for the purpose of reliability assessment and developing flood fragility curves of bridges in which flow velocity and water height are taken as flood intensity measures. Upon validating the proposed method, it is applied to a case study bridge that experiences the flood scenario of a river in Gujarat, India. Research outcome portrays how effectively and efficiently the proposed reliability-based method can be applied for a quick assessment of flood vulnerability of bridges in any flood-prone region of interest.@en

Applying preventive maintenance (PM) strategies to corroded concrete bridge columns along their life spans is essential to reduce sudden loss in bridge functionality during earthquakes and associated risk owing to postearthquake damage. This study identifies optimized applications of condition-based PM for bridge columns with an objective to minimize seismic risk and life-cycle cost (LCC) for applying maintenance interventions. External wrapping of columns with fiber-reinforced polymer (FRP) composites and application of cathodic protection (CP) technique were used as maintenance actions. These maintenance actions were applied in four sequence-oriented strategies, namely simultaneous, FRP followed by CP, CP followed by FRP, and FRP only, to explore the benefit of different application sequences involving FRP and CP. Multiobjective optimization using the Nondominated Sorting Genetic Algorithm-II (NSGA-II) was performed for this purpose. Numerical analyses with a model column identified diverse pools of near-optimal solutions with different FRP materials (i.e., carbon and glass), their number of layers, and time of application of FRP and CP. When comparing solutions from different strategies, it was observed that earlier application of FRP was advantageous to keep the expected seismic risk of the column at a lower level for a longer duration of its design life.@en

The conventional method of seismic design of structures considers the lateral natural period to remain constant during the design process. However, the relatively newly proposed yield point spectra based method instead considers a constant yield displacement as the primary criteria. This article provides a critical comparison of both of these methods through case studies. The conventional method is found to be safe but uneconomic, while the yield point spectra based method is challenging to implement and earthquake data specific. A new iterative technique is proposed in this article, which is based on the methodology of the conventional analysis process but takes into account the main feature of the yield point spectra based design, i.e., to maintain constant yield displacement by varying strength and stiffness accordingly. It is anticipated that the proposed seismic design method will appeal to the designers due to its procedural familiarity and conceptual superiority.@en

This paper describes an innovative biotechnology and civil engineering utilizing Microbiologically induced calcite precipitation MCIP for the improvement in properties of surface concrete. Newly, it is found that microbial mineral precipitation resulting from metabolic activities of favorable microorganisms in concrete enhanced the overall behavior of concrete. Calcite precipitation induced by Bacillus cereus was studied in three different percentage of incorporation of bacterial culture in Portland cement concrete specimens. Bacterial culture was mixed with basic ingredients of concrete to obtain microbial concrete. The addition of bacteria was found out to be very effective in increasing the strength of concrete. About 57% of increase in compressive strength was observed by microbial treatment. Different tests like EDTA and pH have also confirmed presence of calcium carbonate precipitation. Involvement of bacterial culture shows detrimental effect that bacteria can cause on the formation of passive layer that prevents rebar from its corrosion. SEM analysis have also confirmed the presence of bacteria forming spore further the following approach has also found out to be efficient in reducing water permeability in concrete structure.@en