Bridge Abutments Research Articles

Advanced Prediction Models for Scouring Around Bridge Abutments: A Comparative Study of Empirical and AI Techniques

Scouring is a major concern affecting the overall stability and safety of a bridge. The current research investigated the effectiveness of the various artificial intelligence (AI) techniques, such as artificial neural networks (ANNs), the adaptive neuro-fuzzy inference system (ANFIS), and random forest (RF), for scouring depth prediction around a bridge abutment. This study attempted to make a comparative analysis between these AI models and empirical equations developed by various researchers. The current research paper utilized a dataset of water depth (Y), flow velocity (V), discharge (Q), and sediment particle diameter (d50) from a controlled laboratory setting. An efficient optimization tool (MATLAB Optimization Tool (version R2023a)) was used to develop a scour estimation formula around bridge abutments. The findings of the current investigation demonstrated the superior performance of the AI models, especially the ANFIS model, over empirical equations by precisely capturing the non-linear and complex interactions between these parameters. Moreover, the result of the sensitivity analysis demonstrated flow velocity and discharge to be the most influencing parameters affecting the scouring depth around a bridge abutment. The results of the current research highlight the precise and accurate prediction of the scouring depth around a bridge abutment using AI models. However, the empirical equation (Equation 2) demonstrated better performance with a higher R-value of 0.90 and a lower MSE value of 0.0012 compared to other empirical equations. The findings revealed that ANFIS, when combined with neural networks and fuzzy logic systems, produced highly accurate and precise results compared to the ANN models.

Blown sand environment characteristics and bridge sand hazard mechanisms of expressways in the South Tibet Valley.

South Tibet expressways are built in the Yalu Tsangpo valley along the route to high-altitude and cold-temperature valleys, which are the main environmental characteristics of the region. Given that the blown sand environment and its potential harm are unclear, targeted prevention and control are not conducive, but its absence would result in severe wind-sand hazards on these expressways. In this research, the blown sand environment of the South Tibet Valley and the mechanism of sand damage to expressway bridges were studied via field observations, wind tunnel experiments and numerical simulations. The sand-moving wind is mainly west wind. The sand-moving wind frequency, sand drift potential, and maximum possible sand transport quantity are high in winter and spring (November-April) and low in summer and autumn (May-October). The sand drift direction is in the east direction. Expressway bridges have a considerable impact on the near-surface blown sand environment, forming a zone for increasing the wind speed between the top of the slope shoulder of the windward side of the bridge to the center of the bridge abutment, forming a zone for weakening the wind speed between the - 3H distances of the upwind direction to the bottom of the slope middle of the windward side of the bridge, further forming a zone for weakening the wind speed centered in the slope shoulder of the leeward side of the bridge. The wind speed within a distance of 40H downwind direction of the bridge generally did not recover. The wind-sand flow is partially blocked when it passes through the bridge and accumulates near the bridge, which cause harm. The impact of the bridge on the blown sand environment in the downwind is greater than that in the upwind. The results of this study can provide a reference for preventing and controlling wind-sand hazards on South Tibet expressways.

A procedure for addressing the soil-abutment interaction problem in the safety assessment of bridges

The paper proposes a methodology for assessing the seismic soil-foundation-abutment response in the spirit of the sub-structure approach. The methodology is suitable for conventional bridge abutments characterized by massive structural components and accommodates for various structural and soil configurations, from both stratigraphic and topographic perspectives. The abutment is assumed to be rigid, which is a generally acceptable hypothesis given the typical geometry of conventional bridge abutments with walls, orthogonal wingwalls, and a concrete deep or strip foundation. The methodology aligns with codes, which foresees a linear behaviour for the abutments and suggest a low behaviour factor to account for dissipative capabilities due to the backfills and the radiation phenomena in the soil. The soil is assumed to perform elastically, but the overall soil nonlinearity induced by seismic wave propagation can be incorporated into the method using a linear equivalent representation of soil properties. The methodology is applied to a real case study in order to demonstrate its effectiveness in addressing the soil-structure interaction problem and to provide practical suggestions for the method implementation, including possible simplifications.

Utilizing Building Information Modelling Technology To Modelling Abutment: Revit

Building Information Modeling (BIM) has transformed the construction industry by offering a robust platform that integrates design, analysis, and construction processes within a single digital environment. This research explores the application of BIM technology, explicitly using Autodesk Revit, in modeling bridge abutments—an essential component in bridge construction that supports and distributes loads from the superstructure to the foundation. The study aims to demonstrate how BIM enhances the efficiency, accuracy, and sustainability of abutment design and construction. The methodology involves a comprehensive review of existing literature on BIM and bridge abutment design, focusing on technological advancements, case studies, and best practices. Additionally, practical implementation of BIM using Revit is conducted to develop detailed 3D models of abutments, incorporating architectural, structural, and geotechnical elements. The benefits of BIM in this context include improved collaboration among multidisciplinary teams, enhanced visualization capabilities for design optimization, and early detection of clashes and constructability issues. The research investigates the integration of Geographic Information Systems (GIS) with BIM to enhance site selection and environmental assessment phases, ensuring informed decision-making throughout the project lifecycle. Innovations in materials science, such as the use of fiber-reinforced polymers (FRP) and ultra-high-performance concrete (UHPC), are also considered for their potential to enhance the durability and longevity of bridge abutments. Ultimately, this study contributes to advancing the application of BIM in civil engineering, particularly in bridge construction, by showcasing Revit's capabilities in creating accurate, data-rich models that improve project outcomes.

Numerical Study of the Influence of Foundation Compressibility and Operational Loadings on the Seismic Behavior of Geosynthetic Reinforced Soil Bridge Abutments

Numerical Study of the Influence of Foundation Compressibility and Operational Loadings on the Seismic Behavior of Geosynthetic Reinforced Soil Bridge Abutments

Effects of exposure sequence and GGBS cement replacement on performance of concrete subjected to carbonation and chloride ingress

In a variety of applications, such as in tidal zones, abutments of bridges and concrete tunnel linings, reinforced concrete is exposed to both carbonation and chloride ingress. The exposure can be either simultaneous or sequential. However, durability design rarely considers synergistic effects due to carbonation and chloride ingress, even though this may have detrimental consequences for performance. Comparative implications of exposure sequence across different concrete compositions are also unknown. In this study, an experimental investigation on the effects of the sequence of carbonation and chloride ingress was conducted, using two concretes which differ by 50% cement replacement with ground granulated blast furnace slag (GGBS). Specimens were exposed to a combination of 10% CO2 accelerated carbonation and immersion in 3% sodium chloride solution, in either sequence, and compared with companion samples subjected to only one of these aggressive environments. The extent of carbonation was measured using phenolphthalein indicator solution, while silver nitrate and Rapid Chloride Testing provided indicators of the chloride ingress. For both concrete mixes, specimens with prior chloride ingress exhibited a decreased rate of carbonation when compared to specimens with no prior exposure. Conversely, specimens with prior carbonation displayed an increased rate of chloride ingress compared to non-carbonated counterparts and a step in the acid soluble chloride content in the region of the carbonation front. The concrete composition appeared to play a role since a greater increase in chloride diffusion coefficient due to prior carbonation was observed in the mix with 50% GGBS replacement than the mix without. These findings suggest that in concrete structures exposed to air and saline environments, the effects of sequential exposure should be characterised.

Physical model investigation of a hybrid GRS integral bridge abutment under cyclic thermal stresses

GRS integral bridge abutments develop large lateral earth pressure on the facing during seasonal/diurnal thermal expansion/contraction, causing significant surface settlements. To mitigate these issues, researchers prefer the use of different kinds of facing to withstand lateral pressure in conjunction with reinforcing of backfill to reduce surface settlement. The present research investigates the performance of a hybrid integral abutment under lateral movement of the facing due to cyclic thermal expansion/contraction of the bridge deck through scaled down 1 g physical model tests. Using the optimized facing and reinforcement configuration, an integral abutment model was proposed and analyzed under varying rate of loading and different loading offsets for three displacement modes till 100 cycles of excitation. The assessment included the development of lateral pressure on facing, surface settlement, magnitude and location of peak reinforcement forces, followed by evaluating long-term performance in terms of permanent strains, stiffness degradation, and strain energy dissipation. The observations revealed that the proposed model having strong connection between the reinforcement and facing along with inclusion of secondary reinforcements along the entire height of abutment in the bearing zone exhibits rapid dissipation of accumulated strain energy, leading to a 48 % reduction in surface settlement under cyclic thermal stresses.

Estimating velocity distribution and flood discharge at river bridges using entropy theory – insights from computational fluid dynamics flow fields

Abstract. Estimating the flow velocity and discharge in rivers is of particular interest for monitoring, modeling, and research purposes. Instruments for measuring water level and surface velocity are generally mounted on bridge decks, and this poses a challenge because the bridge structure, with piers and abutments, can perturb the flow field. The current research aims to investigate the applicability of entropy theory to estimate the velocity distribution and the discharge in the vicinity of river bridges. For this purpose, a computational fluid dynamics (CFD) model is used to obtain three-dimensional flow fields along a stretch of the Paglia River (central Italy), where a historical multi-arch bridge strongly affects flood flows. The input data for the entropy model include the cross-sectional bathymetry and the surface velocity provided by the numerical simulations. A total of 12 samples, including three different flow conditions at four cross-sections, one upstream and three downstream of the bridge, are considered. It is found that the entropy model can be reliably applied upstream of the bridge, also when forced with a single (i.e., the maximum) value of the surface velocity, with errors on total discharge below 13 % in the considered case. By contrast, downstream of the bridge, the wakes generated by the bridge piers strongly affect the velocity distribution, both in the spanwise and in the vertical directions and for very long distances. Here, notwithstanding the complex and multimodal spanwise distribution of flow velocity, the entropy model estimates the discharge with error lower than 8 % if forced with the river-wide distribution of the surface velocity. The present study has important implications for the optimal positioning of sensors and suggests the potential of using CFD modeling and entropy theory jointly to foster greater knowledge of river systems.

Numerical simulation of impact effect for damage assessment of highway bridge abutments

ABSTRACT Bridge abutments are often damaged by girder impacts during major earthquakes. Very limited studies have been conducted. None of the past studies have incorporated abutment damage as an integrated system, i.e. the interaction between the deck and the back wall as well as between abutment and backfill. First, the reliability of the numerical model for damage assessment is validated with the result obtained from the shaking table test. Second, numerical simulations of the impact effect were carried out on four abutments with different shapes and dimensions of wing wall. The developed numerical models can simulate the nonlinear backfill soil, the backfill-back wall interface, and damage to reinforced concrete with the strain rate effect of the concrete and steel reinforcement. Parametric studies were conducted on the influence of the nonlinearity of the backfill soil, back wall-to-backfill friction, constitutive law of concrete, hourglass ratio, and impact energy. The results show that the nonlinear behaviour of the backfill soil and wing wall plays a significant role in the impact force on the back wall behaviour. Since poundings can be repetitive, this study confirms that the velocity of the initial impact of a bridge deck can precisely predict the severity of abutment damage.

Discussion of “Erosion Mitigation of Bridge Abutment Backfill during Flood Events”

Discussion of “Erosion Mitigation of Bridge Abutment Backfill during Flood Events”

Closure to “Erosion Mitigation of Bridge Abutment Backfill during Flood Events”

Closure to “Erosion Mitigation of Bridge Abutment Backfill during Flood Events”

Influence of Apparatus Scale on Geogrid Monotonic and Cyclic/Post-Cyclic Pullout Behavior in Cohesive Soils

Geosynthetics have increasingly been applied to geotechnical engineering works due to their numerous advantages, including cost-effectiveness and their significant role in sustainable development. When geosynthetics are used as reinforcement in earth structures, such as embankments, retaining walls and bridge abutments, soil–geosynthetic interface shear behavior is a critical parameter involved in the design. This paper presents a series of monotonic and cyclic/post-cyclic pullout tests carried out to examine the apparatus scale effect on the pullout response of a geogrid embedded in two different soils. To assess the small-scale equipment feasibility, comparisons were made between pullout test parameters derived from small- and large-scale equipment. The test results indicate that, under a low confining stress of 25 kPa, using a smaller-sized apparatus results in lower values of geogrid pullout resistance and maximum mobilized shear stress, but higher values of confined tensile stiffness at low strains. On the other hand, as the confining stress increases (i.e., 50 kPa and 100 kPa), the difference between the results becomes less significant and similar trends are observed regardless of the equipment type. Adopting small-scale equipment enables obtaining soil–reinforcement interaction parameters using test procedures that are less time-consuming than those associated with large-scale pullout tests. However, proper scale effect correction factors may be considered for more consistent estimates of the interface strength parameters under low normal stress values.

ArchIMEDES: Computer Vision Tracking of the Inherent Changes to Structural Stability of Masonry Arch Bridges Resulting from Increased Bed Scour.

Scour-induced failure of masonry arch bridges is a common cause of bridge collapse, especially during extreme flood events. Over recent years there has been a significant increase in the numbers of documented scour induced failures of this bridge stock across Europe and the USA. The extent of the scour can erode the supporting soil or sediment around the bridge piers or abutments, leading to a loss of support for the structure. As the foundation becomes unstable, it can result in settlement or tilting of the bridge, potentially causing structural damage, while the ongoing nature of scour can result in the progressive deterioration of the bridge’s ability to safely transfer load. Traditional hydraulic adjustments, such as streamlining abutments with wing walls and using cutwaters on piers, do not significantly reduce scour depth for masonry arch bridges. This paper presents initial findings of an investigation that links the changes of response in load carrying capacity to the easement of support at the bridge foundation due to scour. Scale experiments on the FlexiArchTM under loading with realistic scour conditions is contributing to the development of an algorithm based on the relationship between the structural response of the FlexiArchTM and prevailing scour conditions. The computer vision-based monitoring package ArchIMEDES, developed as part of the research, will use this algorithm to predict current bridge scour conditions at any given time. This will allow for potential scour development to be identified and investigated before the bridge collapses, ensuring the security and safety of these vital pieces of infrastructure.

Numerical Simulation Study on the Hydrothermal Characteristics and Dynamic Response of the Embankment–Bridge Transition Zone in Cold Regions

The chain reaction of bridge abutment structure caused by frost heave of the embankment–bridge transition zone filler in cold regions has a great impact on the smoothness of railway lines, which will bring great challenges to the normal operation, safety, and maintenance of rail transit in cold regions under the action of long-term dynamic load. In this paper, the hydrothermal model and dynamic analysis model of the embankment–bridge transition zone are established, and the frost heave deformation rule and dynamic response characteristics of the embankment–bridge transition zone under frost heave conditions are studied. The results show that the effect of the bridge abutment structure on vertical frost heave is mainly concentrated in the range of the bridge abutment, and the vertical frost heave near the abutment is much smaller than other parts away from the abutment. The dynamic response and wheel–rail contact force of the embankment–bridge transition zone are significantly different under non-frost heave and frost heave conditions. Frost heave may cause a higher risk of derailment. This study provides a scientific reference for the design, construction, and safe operation and maintenance of embankment–bridge transition zones in cold regions, and has certain practical engineering significance.

Zastosowanie predykcyjnych zależności efektów pęcznienia dla podłoży drogowych

Impact of swelling can be observed in a wide range of civil and engineering structures. In the case of swelling in the subsoil of roadbeds, the destruction of the road pavement in cuts or collapse of slopes of cut is a frequent occurrence. Problems with deformation from swelling can also occur in the case of bridge abutments based on pile trestles. The unpleasant fact is that the impact of swelling can occur even after a long time. In the case of roads, high swelling pressures can lead to total destruction of the structure of the pavement even after years of operation. The susceptibility of soil to swelling can be described using swelling parameters. These parameters can be measured directly in the laboratory and in situ or indirectly estimated from empirical correlations. The paper describes the prediction of swelling processes using indirect measurements based on the methodology "Identification and solution of problems of soils prone to swelling" certified by the Ministry of Environment of the Czech Republic.

Seismic fragility assessment of an in-service piled bridge abutment subjected to a liquefaction-induced lateral spreading and mitigation strategy

This study assesses the seismic fragility curves of in-service piled bridge abutments on liquefaction-prone soils and evaluates an optimal countermeasure within the vulnerability framework. Seismic fragility curves, accounting for varying ground motion intensities, assess the seismic risk and describe abutment damage through settlement measurements. The ageing abutment performance is estimated by integrating a corrosion model into fragility curves. The impact of different sheet pile positions on the seismic performance of in-service piled bridge abutments is analysed, and the optimal pile position is discussed. The developed fragility curves provide a rapid and effective risk assessment tool for the seismic performance of in-service abutments and guide liquefaction remedial measures.

Research on construction monitoring of curvilinear continuous beam bridge jacking and horizontal moving construction

This article investigates the issue of beam misalignment in continuous curved beam bridges. Taking the D0–D6 spans of the Gongbin Road elevated bridge as a basis, real-time monitoring of the stress and displacement of the beams is carried out during the jacking and shifting construction process. At the same time, the reaction forces of each support are monitored. The jacking force of the hydraulic jacks is controlled to ensure the stability and safety of the beam during the construction process. Finally, the jacking and shifting monitoring data is organized and compared with theoretical values. It is found that the stress values generated during the jacking phase of the bridge are below the stress control standard. No uplift phenomenon occurs at the supports, and the jacking height is controlled within a reasonable range. The construction process does not cause damage to the beams, and it is safe and reliable. During the shifting construction, the whole bridge was displaced using the jacking method, and the three working conditions were monitored throughout the process. The stress increment at the 2# and 4# sections was relatively small, and the measured stress increments for the entire bridge were all below the stress control standard. The displacement of the bridge abutment during the jacking process was minimal, with no contact with the abutment blocks, and no significant elastic deformation occurred. The jacking displacement was successfully achieved.

Soil-structure interaction issues in integral abutment bridges

Integral Abutment Bridges (IABs) are constructed without expansion joints and bearings, connecting the bridge deck monolithically to the end abutments. Therefore, the construction and maintenance costs of IABs are low compared to conventional bridges with bearings and joints. However, the soil-structure interaction issues are more complex for IABs due to the transfer of deck movements to the foundations through the abutments. Hence abutments of these bridges play an important role in the performance of the substructure and consequently the design approach for the substructure. In this paper, soil-structure interaction issues are investigated for the deck movements due to cyclic thermal loading, which occurs as a combination of daily and seasonal temperature changes. The development of a physical model facility to simulate the problem is described with scaling laws and material properties. The settlement problem at the bridge approach and stress ratcheting phenomena observed at the abutment soil interface are discussed using results from model tests. For the prediction of lateral earth pressure distribution behind abutments, currently available methods are discussed, and modifications are proposed. Finally, the effectiveness of Expanded Polystyrene (EPS) geofoam as an inclusion is discussed to mitigate approach settlement and stress ratcheting problems due to cyclic thermal loading. The results of this study confirm that EPS geofoam is a highly effective material to minimise adverse soil-structure interaction issues in integral bridge abutments.

Investigation into soil ratcheting behind integral bridges using centrifuge modelling

Integral bridges in the UK are commonly designed according to PD 6694-1:2011, with guidance on backfill ratcheting based on experimental data that is limited by testing at a small-scale low-stress state, a lack of abutment foundation and soil below, and a limited range of soil–structure configurations. As integral bridge use increases, there is a need for further understanding of the strain ratcheting mechanism, which can lead to smarter designs that minimise material usage and lifetime maintenance. The suitability of modern centrifuge techniques to simulate ratcheting of soil behind an integral bridge abutment over a design life of thermal loading was investigated. A high-accuracy actuation system was developed and employed in centrifuge testing, with test data provided to demonstrate its capabilities. Surface settlements, deck axial forces and abutment bending moment distributions recorded for various soil–structure combinations were compared, highlighting the sensitivity of soil ratcheting. This work shows that centrifuge modelling can successfully simulate backfill strain ratcheting behind integral abutments over a range of soil–structure configurations. Furthermore, the results suggest that global rotations and base sliding are significant to the overall response, clarifying the importance of modelling at an appropriate stress state with a foundation and the soil below.

Effects of collars in reducing local scour depth around bridge abutments under unsteady flow conditions

Effects of collars in reducing local scour depth around bridge abutments under unsteady flow conditions