Bridge scour

This paper is the continuation of the previous paper i.e. "Analysis and Design of T-beam Super Structure using Limit State Method" where in depth  analysis as well as design is carried out for piers, abutments for both water load and soil load along with dead load and moving load of vehicles. Also foundation design in form of Pile footing as well as supporting pile cap is done though piles are designed uneconomically. Experts may correct the foundation design wherever necessary. The soil report can be found from the very first upload i.e. T-beam bridge super structure.Thank you.

Lacey’s equation is often used to find out the scour depth in rivers in India. Lacey’s regime formula
(1930) was developed on the basis of limited field data from irrigation canals in Punjab Province having
discharge ranges from 0.70 to 173 m3/s. The total scour at a highway crossing is comprised of three
mechanisms: long-term aggradation-degradation, contraction of reach, and local scours at piers and
abutments. In the present study, HEC-RAS model is used to estimate the bridge scour for the Ganges
road bridge and it is then compared with Lacey’s formula. Apparently, more realistic results are
obtained by HEC-RAS model as it considers more related factors as angle of attack, bed conditions,
shape of piers, flow concentrations, flow depth and Froude No. as against discharge intensity and silt
factor considered in case of Lacey’s equation. Comparative study is carried out for different angles of
attack and restricted flow condition near the bridge site. From the restriction of waterway by 3.6 km to
2 km, abutment scour and contraction scour change 1.6 times and 3.9 times respectively. So, the
waterway has significant role for the bridge foundation design. By changing angle of attack by 5 °, the
change in pier scour is 10%.

Balanced cantilever bridges are used for special requirements like 1) Construction over traffic 2) Short lead time compared to steel 3) Use local labour and materials. If continuous spans are used, the governing bending moment can minimised and hence the individual span length can increase. But unyielding supports are required for continuous construction. Hence for the medium span in the range of about 35 to 60 m, a combination of supported span, cantilever and suspended span can be adopted and bridge with this type of superstructure is known as balanced cantilever bridge. This chapter include the analysis and design of a 50m span prestressed balanced cantilever bridge which comprises of 6 numbers of PreCast Post Tensioned-I Girder 38m long Simply Supported at one end and connected through a Cast-in-Situ Stitch Concrete to a Continuous Balanced Cantilever Box Girder (2x11m). The bridge structure has been modelled by Finite element Technique using MIDAS Civil and analysis has been performed to get various output such as primary and secondary bending moment, shear forces and torsion quantities at various locations of the bridge. The design of super structure is performed as per IRC standards. Keywords— Balanced cantilever bridge, Prestressed, I girder, Box girder, Primary and secondary moments and MIDAS Civil I. INTRODUCTION Balanced Cantilever Bridge is so named due to its method of construction. It is one of the most efficient methods of building bridges without the need of false work. This method has great advantages over other forms of construction in urban areas where temporary shoring would disrupt traffic and services below, in deep gorges, and over waterways where false-work would not only be expensive but also a hazard. Construction commences from the permanent piers and proceeds in a " balanced " manner to mid span. Before starts design dimensions are assumed based on experience. The design involves calculation of the section properties, primary and secondary moments, magnitude and location of the prestressing force, profile of the tendons, losses due to prestressing, shear stresses at different sections.

Empirical equations, widely practiced by hydraulic engineers, applicable to different scour components are presented. Prediction patterns with these different equations, using available compiled data, are then presented. Pertinent bridge hydraulics variables are also presented with an objective of facilitating a dynamic spreadsheet analysis. Finally a sample scour calculation example is presented.

This approach paper specifically addresses the sediment load that is expected in the river, in reaches in the immediate vicinity of the river and that further upstream. The objective remains an assessment of adverse impacts such sediment load may possibly have at the bridge location and measures that will be necessary (if any) to address such adverse impacts. Further, being integrally related to the sediment load and the sediment characteristics of the river bed, scour is another aspect that this approach paper delves into.

This study was carried out at the irrigation and hydraulic laboratory at the faculty of Engineering, Mansoura University for studying characteristics of the scour hole around pile groups.
      The objective of the study is to investigate how the scour hole characteristics are affected in magnitude by the Froude number, piles diameters, piles gap, and pile group orientation,
      A recirculating flume type was used. The model of piles was placed in the flume, equidistant from the walls. Sand was used as bed material up to a depth equals 0.15m with mean diameter 0.52 mm.       
      A sum of about 234 experiments were carried out for different piles diameters, piles gap, pile group orientation, and different Froude numbers.      the Froude number ranged from 0.22 to 0.38, to obtain non-dimensional relationships between the design parameters.
      Empirical relationships were developed from dimensional analysis based on the data obtained from the experimental tests. Computer analysis and regression methods were used to deal with the experimental data and finally to get formulas and relationships relating scour parameters to the flow parameters.

Foundation scour is among the main causes of bridge collapse worldwide, resulting in significant direct and indirect losses. A vast amount of research has been carried out during the last decades on the physics and modelling of this phenomenon. The purpose of this paper is, therefore, to provide an up-to-date, comprehensive, and holistic literature review of the problem of scour at bridge foundations, with a focus on the following topics: (i) sediment particle motion; (ii) physical modelling and controlling dimensionless scour parameters; (iii) scour estimates encompassing empirical models, numerical frameworks, data-driven methods, and non-deterministic approaches; (iv) bridge scour monitoring including successful examples of case studies; (v) current approach for assessment and design of bridges against scour; and, (vi) research needs and future avenues.

Scour is the erosion of sand and rock by the action of flowing water, which causes stream stability problems, as well as bridge failures. Scour around bridge foundations is one of the leading causes of bridge failure which affects hundreds of thousand bridges and costs hundreds of millions of dollars in direct repair costs. Scour is a common soil-structure interaction problem. Hence, this necessitates a profound research in the area of scour protection to avoid the bridge failures. This paper intends to discuss various types and mechanisms of scour and existing laboratory experimental setup for the bridge scour monitoring. The current review also explains several pier scour monitoring devices such as Sonars, Magnetic Sliding Collars (MSC), Float out devices, Time Domain Reflectometry (TDR), Fibre Bragg Grating (FBG), Ground Penetrating Radar (GPR) which are used to measure the scour depth around the pier. The review also discusses about Soft Computing techniques such as ANN, SVM, and ANFIS etc. are recently used for prediction of bridge scour using field or experimental data. The paper also provides the advantages and limitations of the scour monitoring devices and soft computing techniques.

River bridges experience more inconvenient conditions due to the structure-flow interaction compared to bridges having no contact with flow. Therefore, one of the most important components of the bridge failure risk is the risk induced by soil-flow interaction. In this study, the uncertainties of the hydrological and hydraulic parameters affecting the scouring around bridge piers are examined using appropriate probability density functions. In the analyses, the uncertainties involved in the temporal variation of clear water scouring mechanism are considered. Influences of general bed degradation of the main channel and the contraction scour are ignored. The risk associated with the scouring around piers is estimated using Monte Carlo simulations. In the model, the scouring risk of the bridge pier is determined for the given flow, pier geometry and bed material characteristics. The developed model is presented with an application.

Laboratory data for local scour depth regarding the size of wide piers are presented. Clear water scour tests were performed for various pier widths (0.06, 0.076, 0.102, 0.14 and 0.165 m), two types of pier shapes (circular and rectangular) and two types of uniform cohesionless bed sediment (d 50 ¼ 0.23 and d 50 ¼ 0.80 mm). New data are presented and used to demonstrate the effects of pier width, pier shape and sediment size on scour depth. The influence of equilibrium time (t e) on scouring processes is also discussed. Equilibrium scour depths were found to decrease with increasing values of b/d 50. The temporal development of equilibrium local scour depth with new laboratory data is demonstrated for flow intensity V/V c ¼ 0.95. On the other hand, the results of scour mechanism have shown a significant relationship between normalized volume of scoured and deposited with pier width, b. The experimental data obtained in this study and data available from the literature for wide piers are used to evaluate predictions of existing methods.

Bridge pier scouring is an important issue for safety evaluation of bridges. The existing equations for bridge pier scour prediction are mostly deterministic in nature, which do not incorporate the uncertainties in various parameters of scouring. A methodology for reliability analysis of bridge pier against scour in cohesive sediments incorporating the uncertainties of the model and input parameters are presented herein using efficient spreadsheet algorithm for first order reliability method (FORM). The influence of uncertainties, the nature of probability distribution and correlation of basic input parameters on failure probability and reliability index has been studied and described briefly herein. A sensitivity analysis was also carried out to obtain the effect of the individual random variables on the reliability of pier scour. To achieve the desired safety level in the design of pier foundation, the reliability-based safety factor is proposed.

The scour modelling in cohesive beds is relatively more complex than that in sandy beds and
thus there is limited number of studies available on local scour at bridge abutments on cohesive
sediment. Recently, a good progress has been made in the development of data-driven techniques
based on artificial intelligence (AI). It has been reported that AI-based inductive modelling
techniques are frequently used to model complex process due to their powerful and non-linear model
structures and their increased capabilities to capture the cause and effect relationship of such
complex processes. Gene Expression Programming (GEP) is one of the AI techniques that have
emerged as a powerful tool in modelling complex phenomenon into simpler chromosomal
architecture. This technique has been proved to be more accurate and much simpler than other AI
tools. In the present study, an attempt has been made to implement GEP for the development of
scour depth prediction model at bridge abutments in cohesive sediments using laboratory data
available in literature. The present study reveals that the performance of GEP is better than nonlinear
regression model for the prediction of scour depth at abutments in cohesive beds.

Accurate and reliable estimation of the scour depth at a bridge pier is essential for the safe and economical design of the bridge
foundation. The phenomenon of scour at the pier placed on sediments is extremely complex in nature. Only a limited number of
studies have been reported on local scour around bridge piers in cohesive sediment mainly due to the fact that scour modeling in
cohesive beds is relatively more complex than that in sandy beds. Recent research has made good progress in the development of
data-driven technique based on artificial intelligence (AI). It has been reported that AI-based inductive modeling techniques are
frequently used to model complex process due to their powerful and non-linear model structures and their increased capabilities
to capture the cause and effect relationship of such complex processes. Gene Expression Programming (GEP) is one of the AI
techniques that have emerged as a powerful tool in modeling complex phenomenon into simpler chromosomal architecture. This
technique has been proved to be more accurate and much simpler than other AI tools. In the present study, an attempt has been
made to implement GEP for the development of scour depth prediction model at bridge piers in cohesive sediments using
laboratory data available in literature. The present study reveals that the performance of GEP is better than nonlinear regression
model for the prediction of scour depth at piers in cohesive beds.

This paper presents results of an investigation on the effects of different parameters on the structural behavior of a skewed integral bridge. Flow velocities affected the scour depths at the piles, and subsequently, affected the structural behavior of the bridge’s substructure. Different loading locations had varying influences on the scour depth, as well as the structural behavior of the integral bridge. Laboratory tests on a scaled down hydraulic model were undertaken to simulate the structural behavior of the scoured integral bridge. The scale of the model was chosen to simulate the actual bridge dimensions, material properties, and loading. Three different velocities were accounted for, based on the actual flow velocities of the river under the bridge, and were scaled according to the model size. Two different truck locations were adopted. The main data acquired from the experiment were the displacements and strains at specific locations on the deck slab and piles. Specifically, the results of this investigation can be utilized to identify and provide accurate design parameters for the design of a skewed integral bridge. Furthermore, results can subsequently be applied in the design of a better scour protection system.

Extensive research has been carried out to predict bridge pier scour, with laboratory and field data, using different modelling techniques. This study introduces a new soft computing technique called gene expression programming (GEP) for pier scour depth prediction using field data. A functional relationship has been established using GEP and its performance is compared with other inductive modelling techniques such as artificial neural networks (ANNs) and conventional regression-based techniques. Field data comprising 370 data sets were collected from the published literature and divided into calibration and validation (testing) data sets. The performance of GEP was found to be satisfactory and encouraging when compared with regression and ANN models in predicting bridge pier scour depth.  GEP has the unique capability of providing a compact and explicit mathematical expression for computing bridge scour. This advantage of GEP over ANN is one of the main motivations for this work. The resulting GEP models add to the existing literature on artificial intelligence based inductive models that can be used effectively for bridge scour modelling.

Based on recent contributions regarding the treatment of unsteady hydraulic conditions into the state-of-the-art of scour literature, the theoretically derived probability distribution of bridge scour is introduced. The model is derived assuming a rectangular hydrograph shape with a given duration, and random flood peak following a Gumbel distribution. A model extension for a more complex flood event is also presented, assuming a synthetic exponential hydrograph shape. The mathematical formulation can be extended to any flood-peak probability distribution. The aim of the manuscript is to move forward the current approaches adopted for the bridge design coupling hydrological, hydraulic, and erosional models in a mathematical closed form.

Advantages of integral bridges include reduction of initial construction and maintenance cost. Scour was the main problem which caused the bridges to fail and collapse during heavy rain and flooding. Most of the previous studies focused on the scouring impact on ...

Accurate estimation of scour depth at complex pier leads to an economic and correct design for level of foundation. Due to technical and economic reasons, complex piers (pier including foundation) are more general for bridge design. In this study, two robust techniques, artificial neural networks (ANNs) and Gene Expression Programming (GEP) were employed for prediction of scour depth at complex piers. A wide range of dataset was collected from present study as well as literature, the clear water condition was chosen for experimental tests. The result shows that the scour depth at complex piers is a function of pier diameter (b c) and foundation level (Y). The RBF (Radial Base Function) network with R 2 =0.945 and RMSE =0.031 provides better prediction in comparison with previous equations and the GEP techniques (R 2 =0.811and RMSE=0.263). A formula was developed using GEP to predict local scour at complex piers. Although, accuracy of the RBF is higher than GEP, the GEP based formula is more useful for practical purposes and can be easily employed to predict the depth of scour at complex piers. This paper highlights that the mentioned techniques can be successfully used for accurate estimation of local scour and lead to the protection of bridge piers.

The phenomenon of scour, cause erosion around bridge piers and consequently may result in failure of foundations and bridge collapsing. Bridge piers through flow streams, reduce flow path, increase the flux per unit width and increase shear stress in narrowed section. Eventually collision of flow with bridge pier causes the precession of the normal current to the side of the pier and channel bed. To prevent or to reduce occurrence of such a phenomenon a range of solutions are presented. One of the engineering approaches to reduce the local scour involves locating slots in the bridge piers. In the current paper the effectiveness of introducing slots on the piers in reduction of the scour depth around the cylindrical bridge piers, under clear water condition with time development has been studied. To determine the scour depth 2 numerical methods and CFD-based modeling have been used. A large amount of data were gathered from the Soil Conservation in Watershed Management Research Institute (SCWMRI) laboratory for modeling and the scour depths in the piers based on different slots elevations have been compared with none slotted pier " s scour. Imaginary three sizes of slots are used; slot No.1 with dimension 30x10 mm (l*b), slot No.2 with dimension 15x15 mm and slot No.3 with dimension 7.5x20 mm. The slots are positioned at 3 levels of 0, 1/3 and 2/3 of flow depth which equals to 0, B and 2B of circular pier diameter (B) compared. Two amounts of discharges; 5 lit/sec and 7 lit/sec were used on all the models. With the non-slotted piers 20 scenarios were studied in total. At the end of analyses it was found that, slots with wider width and shorter height which are located in near the flow surface would result in minimum scour depth. In this case, the scour depth would be reduced by 20% compared to the pier without any slot. Also slots with greater heights and less width which are located near the channel bed are the worst scenarios.

In Taiwan, the typhoon cause great damage on bridge due to Bridge Scour. Hence, the monitoring of Bridge Scour has received considerable interest in the last decade. However, traditional site investigation methods and conventional wired sensing system are expensive and time-consuming and may not always give a complete assessment. Characterized by its low manufacturing costs, low power requirements, miniaturized size, and no need for cabling, the wireless sensor networks (WSN) is an attractive sensing technology for deploying dense distributed sensors in bridge. This study proposed an Imote2.NET-based wireless monitoring system which is deployed in Nioudou Bridge in Taiwan. A field free vibration test was conducted for obtaining dynamic response from wireless sensors. Experimental analysis confirms the high quality of data collection by the proposed reliable data-sensing and transmission protocol. This protocol provided excellent data sensing and transmission quality for determining dynamic structural properties. The field results indicate that the proposed wireless system was a suitable technology for monitoring Bridge Scour.

Riverbed erosion due to flooding events presents one of the main challenges for transportation infrastructure. During extreme weather events, the risk of flood-induced structural failures is increased substantially due to scour at the foundations of bridges. This is particularly evident for the case of energetic flow structures, which accelerate erosion processes of downstream soil material and often leads to damage of scour protection systems (Valyrakis et al., 2013). This study aims to assess failure risk of scour protection systems and erosion of adjacent areas and provide and understanding of the evolution of critical flows and scour processes. This is accomplished with the application of two different sensing instruments to (a) monitor the probability of entrainment of an instrumented particle appropriately positioned on the surface of a protective layers (Al-Obaidi et al., 2020) and (b) provide real-time assessment of scour evolution on the riverbed adjacent to the bridge foundation using a new electromagnetic sensor (Michalis et al., 2019). Flume experimental testing under well controlled flow conditions is carried out to evaluate the change in entrainment frequencies based on the instrumented particle response positioned downstream a physical model of a bridge. At the location of the bridge pier the EM sensor is installed to record the evolution of riverbed changes. Flow profiles are also continuously obtained at specific space intervals downstream the simulated bridge pier with an Acoustic Doppler velocimetry (ADV). The obtained dataset is analysed to assess the energetic turbulent flow mechanisms that accelerate scour driving forces resulting in excessive erosion and damage of protective layers (Pähtz et al., 2020).

References

Al-Obaidi, K.; Xu, Y.; Valyrakis, M. The Design and Calibration of Instrumented Particles for Assessing Water Infrastructure Hazards, J. Sens. Actuator Netw. 2020, 9(3), 1-18, https://doi.org/10.3390/jsan814323.

Michalis, P.; Tarantino, A.; Tachtatzis, C.; Judd, M.D. Wireless monitoring of scour and re-deposited sediment evolution at bridge foundations based on soil electromagnetic properties, Smart Materials and Structures. 2015, 24(12), pp. 125029.

Pähtz, T. ; Clark, A. H.; Valyrakis, M.; Duran, O. The Physics of Sediment Transport Initiation, Cessation, and Entrainment Across Aeolian and Fluvial Environments.

Advantages of integral bridges include reduction of initial construction and maintenance cost. Scour was the main problem which caused the bridges to fail and collapse during heavy rain and flooding. Most of the previous studies focused on the scouring impact on conventional and traditional bridge. Very few studies investigated on scouring effects on integral bridge and its countermeasure. This paper highlighted the innovative countermeasure to prevent the impacts and consequences of scouring on integral bridge.

Scour has been recognized as one of the primary reasons for bridge pier destabilization. As extreme weather intensifies and hydraulic infrastructure such as bridge piers and abutments (many constructed since the Victorian era, for the case of the UK) continues to age, the challenge of scour-induced hazards will keep growing impacting the resilience of our society. Thus, there is an increasing value in studying the highly dynamical process of scour around hydraulic infrastructure. Maximum scour depth estimation has been broadly studied by researchers over the past decades, using phenomenological or empirical approaches, linking mean flow properties, bridge pier and riverbed materials characteristics [1, 2].

This study aims to get a better understanding of how the turbulent flow field modified by the bridge pier, interacts with the bed surface towards the generation of the scour hole. This is pursued by following a dynamical approach via assessing the flow structures that are sufficiently energetic [3] to remove bed material from the vicinity of the bridge pier.

A series of scour experiments with different length scale of model bridge piers is conducted in a water recirculating research flume. For each of these cases flow velocity profiles are collected downstream the bridge pier using high resolution acoustic Doppler velocimetry (ADV). Using the raw data collected near the bed surface and information for the bed surface material, the criterion of impulse [4] is used as a metric for assessing the extend and maximum scour depth. The results are compared for the different measurement locations are compared to better understand the process of scour downstream different model piers.

[1]. M Valyrakis, P Michalis, H Zhang, (2015). A new system for bridge scour monitoring and prediction, Proceedings of the 36th IAHR World Congress, 1-4.

[2]. Yagci, O., Celik, M. F., Kitsikoudis, V., Ozgur Kirca, V.S., Hodoglu, C., Valyrakis, M. , Duran, Z. and Kaya, S. (2016) Scour patterns around isolated vegetation elements. Advances in Water Resources, 97, pp. 251-265.(doi:10.1016/j.advwatres.2016.10.002)

[3]. Valyrakis, M. , Diplas, P. and Dancey, C.L. (2013) Entrainment of coarse particles in turbulent flows: an energy approach. Journal of Geophysical Research: Earth Surface, 118(1), pp. 42-53. (doi:10.1029/2012JF002354)

[4]. Valyrakis, M. , Diplas, P., Dancey, C.L., Greer, K. and Celik, A.O. (2010) Role of instantaneous force magnitude and duration on particle entrainment. Journal of Geophysical Research: Earth Surface, 115(F02006), 18p. (doi:10.1029/2008JF001247)

Flood frequency and its magnitude are essential for the proper design of hydraulics structures such as bridges, spillways, culverts, waterways, roads, railways, flood control structures and urban drainage systems. Since, flood is a very complex natural event depending upon characteristics of catchment, rainfall conditions and various other factors, thus its analytical modelling is very difficult to pursue. Recently, artificial intelligence techniques such as gene expression programming (GEP), artificial neural network (ANN) etc. have been found to be efficient in modelling complex problems in hydraulic engineering. The performance of GEP model has been reported to be better than that of the ANN. Moreover, GEP provides mathematical equation which makes it more superior over other soft computing techniques that do not give any analytical mathematical equation. Therefore, in present study, GEP is implemented in flood frequency analysis for typical Indian river gauging station. The results obtained in the present study are highly promising and suggest that GEP modelling is a versatile technique and represents an improved alternative to the more conventional approach for the flood frequency analysis.

The piers and abutments in the bridges are naturally eroded during strongest flood. There are three types scour: contraction scour, scour at piers and scour at abutments. This article contains the main empirical methods used to estimate the scour depth for each type. Several examples are included in which illustrates how are used the methods mentioned. The bridges may modify the morphology of the rivers, for this reason, this information could be useful in the environmental engineering field.

-For a long while, scour mechanism has been a major problem to be solved by many researchers. Local scour phenomenon at bridge piers has many parameters such as flow characteristics, sediment type, bridge pier shape and alignment. To find a general scour equation under the same conditions, the effect rate of any parameter has to be determined. After the determination phase, the rectifier coefficients for a valid equation can be easily calculated for scour estimation. In order to specify whether the scour condition is clear-water or live-bed, the velocity parameter has to be substituted into scour equations because the determinative factor between these two conditions is the flow velocity. Accordingly in this study, the effect of the ratio of mean approach flow velocity to the critical mean approach flow velocity for entrainment of bed sediment (V/Vc) has been investigated. Three of the mostly used empirical scour formulations, did not take into account the flow velocity, but they ar...

Scour action still remains the leading cause of numerous bridge failures each year and is considered one of the most destructive flood related hazards occurring around underwater foundation elements [1]. Undetected erosion related processes are therefore the cause of major disruptions to the transportation network with significant socioeconomic losses and disruption to users, maintainers and asset owners. Recent cases of bridge failures due to extreme climatic events have highlighted the need for a reliable scour monitoring and early warning system to assess flood and geo-related hazards in real-time, providing advanced key info for repair and maintenance actions. Despite the past efforts to provide such a system for scour assessment, most of these instruments have not managed to realise a solution for scour monitoring due to technical and cost issues. The existing practices to assess, manage and maintain transportation assets are mainly based on visual inspection procedure which is also considered to be insufficient [2]. As a result there currently exists a gap in the knowledge and understanding of scour mechanism during flood incidents. This study presents the architecture of 'Climatic Hazard Monitoring and Bridge Scour Early Warning System' (CliHaMoS) project, which is expected to significantly assist towards the optimisation of bridge performance against scour issues with a real-time data driven approach. CliHaMoS platform comprises of a new structural health monitoring system based on a novel bio-inspired sensing system aiming to deliver key information under different hydrodynamic events for real-time and forecasted assessment of flood hazards at bridges. The sensing solution is coupled by an early warning system, with advanced interoperability characteristics, to provide a holistic interactive platform and ensure that risks associated with flood hazards are properly and timely communicated to end-users. The obtained information is expected to enable stakeholders to plan adaptation strategies and proactively manage and maintain transportation infrastructure.

References:

[1] Michalis, P., Saafi, M., and Judd. M. (2013) Capacitive sensors for offshore scour monitoring. Proceedings of the ICE – Energy, 166 (4), pp. 189-197

[2] Michalis, P., Saafi, M. and Judd, M. (2012) Wireless sensor networks for surveillance and monitoring of bridge scour. Proceedings of the XI International Conference Protection and Restoration of the Environment - PRE XI. Thessaloniki, Greece, pp. 1345–1354.

ACKNOWLEDGMENT:

This research is co-financed by Greece and the European Union (European Social FundESF) through the Operational Programme «Human Resources Development, Education and 4 Lifelong Learning» in the context of the project “Reinforcement of Postdoctoral Researchers - 2nd Cycle” (MIS-5033021), implemented by the State Scholarships Foundation (ΙΚΥ).

Scour and other hydraulic processes can be responsible for compromising the stability of built infrastructure such as highway structures or embankments supporting roads, particularly in the vicinity of water bodies. Intense scour and flooding during large flows can cause structural failure or even lead to loss of life. Considering climate change, the magnitude and frequency of these processes can only increase, along with the threat posed to infrastructure, rendering it necessary to identify risks at the earliest possible stages. This study aims to offer a preliminary insight into the use of sensing options, enabling the real time monitoring of environmental hazards and water surface (for detection of flooding) at the vicinity of bridge supports , towards the application of a sufficiently robust early warning system according to the relevant guidance offered by the Scour Management Strategy and Flood Emergency Plan.

This paper presents finite element modelling of the effects of different flow velocities on the structural behaviour of a skewed integral bridge. Flow velocities affect the scour depths at the piles of a bridge and thus affect its structural behaviour. Laboratory tests on a scaled-down hydraulic model along with numerical modelling were performed to simulate the structural behaviour of the scoured integral bridge. A finite element package was used for the numerical modelling work, and the displacements and strains corresponding to the measured locations on the physical model were extracted. The experimental and numerical results for the case of maximum scour depths were compared. © 2011 Elsevier B.V. All rights reserved.

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