Bridge Foundations Research Articles

A new calculation method for the response of active-passive bridge piles considering pile-soil interface friction

The pile foundation of bridges under unregulated surcharge loads experiences a complex force pattern, which is subject to active loads and passive loads. In this paper, a more comprehensive calculation method for the response of active-passive piles was proposed, which considered the effect of pile-soil interface friction and soil stress states on the passive loads. First, the Ito theory was improved by adopting the adhesion c a and external friction angle φ a to characterize the pile-soil interface friction. Then, the soil around the pile in elastic, elastoplastic, and plastic flow states was considered to calculate the variation of the passive load. Finally, a nonlinear p-y curve was introduced to establish the calculation model of active-passive piles, and the finite difference program CPAPP was prepared for the solution. The results show that the pile response calculated by CPAPP is consistent with the field measurement, indicating that the proposed calculation method has high accuracy. When the soil is in an elastic state, the pile-soil interface friction does not affect the passive load. When the soil is in a plastic state, the passive load is closely related to soil strength parameters and pile-soil interface friction parameters.

Analysis of Local Scour around Double Piers in Tandem Arrangement in an S-Shaped Channel under Ice-Jammed Flow Conditions

The stability of bridge foundations is affected by local scour, and the formation of ice jams exacerbates local scour around bridge piers. These processes, particularly the evolution of ice jams and local scour around piers, are more complex in curved sections than in straight sections. This study, based on experiments in an S-shaped channel, investigates how various factors—the flow Froude number, ice–water discharge rate, median particle diameter, pier spacing, and pier diameter—affect the maximum local scour depth around double piers in tandem and the distribution of ice jam thickness. The results indicate that under ice-jammed flow conditions, the maximum local scour depth around double piers in tandem is positively correlated with the ice–water discharge rate, pier spacing, and pier diameter and negatively correlated with median particle diameter. The maximum local scour depth is positively correlated with the flow Froude number when it ranges from 0.1 to 0.114, peaking at 0.114. Above this value, the correlation becomes negative. In curved channels, the arrangement of double piers in tandem substantially influences ice jam thickness distribution, with increases in pier diameter and spacing directly correlating with greater ice jam thickness at each cross-section. Furthermore, ice jam thickness is responsive to flow conditions, escalating with higher ice–water discharge rates and decreasing flow Froude numbers.

Uncertainty and Latin Hypercube Sampling in Geotechnical Earthquake Engineering

A soil–foundation–structure system (SFSS) often exhibits different responses compared to a fixed-base structure when subjected to earthquake ground motion. Both kinematic and inertial soil–foundation–structure interactions can significantly influence the structural performance of buildings. Numerous parameters within an SFSS affect its overall response, introducing inherent uncertainty into the solution. Performing time history analyses, even for a linear elastic coupled SFSS, requires considerable computational effort. To reduce the computational cost without compromising accuracy, the use of the Latin Hypercube Sampling (LHS) technique is proposed herein. Sampling techniques are rarely employed in soil–foundation–structure interaction analyses, yet they are highly beneficial. These methodologies allow analyses determined by sampling to be conducted using commercial codes designed for deterministic analyses, without requiring any modifications. The advantage is that the number of analyses determined by the sampling size is significantly reduced as compared to considering all combinations of input parameters. After identifying the important samples, one can evaluate the seismic demand of selected soil–foundation–bridge pier systems using finite element numerical software. This paper indicates that LHS reduces computational effort by 60%, whereas structural response components (translation, rocking) show distinct trends for different systems.

A meshless model for three-dimensional direct numerical simulation of local scour around cylinder bridge foundation

A meshless local scour model for cylinder bridge foundation based on the smoothed particle hydrodynamics (SPH) method is proposed in this paper. Differing from the traditional Eulerian mesh model used for monopile local scour, it overcomes the high requirements of mesh quality and density for capturing large deformations at the fluid interface. Unlike the transient sediment erosion SPH model used for dam-break, sediment flushing, and water jet, the meshless approach is innovatively applied to the continuous simulation of bridge local scour under steady flow conditions. The present SPH model is established based on the SPH multi-phase fluid model, integrating a classical fluid model combined with numerical stabilization algorithms to govern water particle motion and a sediment model from Zhang et al. (2024) to govern sediment evolution, and tests a new scheme for boundary treatment in the model based on DualSPHysics. Furthermore, a novel scour visualization method that aims at extracting both visible and actual bed surfaces from discrete particles is proposed. The model is validated through comparison with rigid bed and live bed experiments, demonstrating favorable agreement in terms of flow and scour simulation. Importantly, the model results reveal a discrepancy between the elevation of the post-scour visible bed surface derived from the conventional Eulerian mesh model and experimental data, compared to the actual bed surface unaffected by water flow erosion. This indicates the necessity for incorporating a safety margin in foundation design when utilizing experimental results to determine the maximum scour depth.

Experimental investigation on the mechanism of local scour around a cylindrical coastal pile foundation considering sloping bed conditions

Sea-crossing bridges are often subjected to local scour, significantly impacting the bearing capacity of the foundation system and potentially leading to bridge failures. This study presents experimental investigations of local scour around a cylindrical pile under different sediment slope conditions in unidirectional currents. Unlike previous studies that focused on horizontal sediment beds, this research explores the influence of inclined sediment beds, which reflect coastal and offshore topographies, which have some angles of inclination. Utilizing flume tests, the research investigates the evolution of scour depth, scour range, and the morphology of the sediment bed across various angles of inclination. The study also evaluates the effectiveness of a scour countermeasure involving rip-rap material around the pile on sloping beds. Specifically, a steeper inclination angle induces a faster flow velocity, resulting in increased scour depth at the upstream side of the pile and a reduced scour range at the downstream side due to backfilling. The countermeasure scenario reveals a significant reduction in both scour depth and range. This research provides analysis of the effects of inclined sediment beds, which reflect coastal topographies than horizontal ones, thereby providing insights for the design and protection of bridge foundations in diverse coastal conditions.

Study on Ground Motion Amplification in Upper Arch Bridge Due to “W”-Type Deep Canyon Using Boundary-Integral and Peak Frequency Shift Methods

The study of the dynamic response characteristics of “W”-type deep canyon terrain to double-span concrete arch bridges under earthquake action holds great practical significance. In this research, a bridge in Sichuan Province is taken as the object of study. The boundary-integral equation method and peak frequency shift method are combined to apply an embedded linear time–history analysis algorithm to the finite element spatial dynamic calculation model of the entire bridge, resulting in an improved model. By comparing these two methods with model test results, the seismic response characteristics of the middle part of a “W” concrete arch bridge under different foundation depths and seismic intensities are examined. The boundary integral equation method was utilized to calculate ground motion response at any point on site, revealing a significant amplifying effect of increased seismic wave intensity on acceleration response at the top of the arch bridge. When input seismic wave intensity increased from 0.1 g to 0.3 g, maximum acceleration at buried depths of 3 m and 8 m in the middle of the arch bridge foundation increased by 102.63% and 79.16%, respectively, indicating that shallow buried depth structures are more sensitive to seismic wave intensity. Furthermore, using peak frequency shift rules for analyzing seismic wave propagation characteristics in “W”-type deep canyon topography confirms the sensitivity of shallow buried depth structures to seismic wave intensity and reveals the mechanism through which topography influences seismic wave propagation. This study provides a helpful method for understanding the propagation law and energy distribution characteristics of seismic waves in complex terrain. It was observed that the displacement at the top of the arch bridge increased significantly with an increase in seismic intensity. When subjected to 0.1 g, 0.2 g, and 0.3 g EI-Centro seismic waves, the maximum displacement at the top of the arch bridge model with a foundation buried depth of 3 m was 8 mm, 32 mm, and 142 mm, respectively. For arch bridge models with an 8-m foundation buried depth, these displacements were measured at 6.2 mm, 21 mm, and 68 mm, respectively. The results from model tests verified that increasing the depth of foundation burial effectively reduces the displacement at the top of the structure. Furthermore, by combining a boundary-integral equation method and peak-frequency shift method, this study accurately predicted significant influences on W-shaped double deep canyon topography from seismic response, and successfully captured stress concentration and seismic wave amplification/focusing effects on arch foot structures. The calculated results from both methods align well with model test data which confirm their effectiveness and complementarity when analyzing seismic responses under complex terrain conditions for bridge structures.

Compressive strength prediction of cement base under sulfate attack by machine learning approach

Cement-based materials in underground structures, bridge foundation, and offshore platforms often face sulfate environments. It has been widely reported that the compressive strength (CS) of these materials post sulfate attack is crucial for structural stability and durability. However, existing experimental and analytical methods require extensive resources and lengthy period. For addressing this challenge, therefore, a novel stacking model is proposed to accurately predict the CS of cement base under sulfate attack in this study. The stacking model integrates Support Vector Regression (SVR), Random Forest (RF), and Extreme Gradient Boosting (XGB) as base learners, with Linear Regression (LR) as the meta-learner. In this novel model training, the 330 data sets used are obtained from the relevant literatures. The water-cement ratio, cement content, water content, sand content, sulfate concentration, wetting temperature, wetting time, drying temperature, drying time, exposure time are selected as inputs while the output is CS of cement-based materials subjected to sulphate deterioration. To improve the forecast capability, particle swarm optimization (PSO) is adopted for optimizing hyperparameters of stacking model, which can be implemented by reducing the discrepancy between model prediction and measured CS. By comparing with the results of experiments and the solely machine learning (ML) models, it is found that the stacking model optimized by PSO presents the best prediction accuracy of R²=0.992, RMSE=2.248 MPa, and MAE=1.782 MPa. Moreover, the examination of the influence of individual input variables on the CS of cement-based material subjected to sulfate attack is conducted through the application of Shapley Additive Explanations (SHAP) and Partial Dependence Plot (PDP) analyses. The PSO optimized stacking model proposed in this study can effectively predict the CS of cement-based materials under sulfate attack. Our study provides a new reference for future research in this field.

Construction Technology for Roadbed and Pavement of Highway Bridge Settlement Section

In the transition area between highways and bridges, settlement often occurs. Even in the transition zone, small differences in settlement between bridge piers and embankments can easily lead to the occurrence of bridge head jumping events. Bridgehead jumping not only affects the comfort, speed, and safety of driving, but also creates a negative impression on the overall image of highways, shortening the service life of cars. At the same time, it can also affect the efficiency and availability of road traffic, and may even lead to traffic safety accidents. Based on an in-depth analysis of the settlement and deformation mechanism of highway bridge foundations, we have discussed the construction technology of road bridge settlement embankments.

Cyclic response of floating geosynthetic-encased steel slag columns in soft clay

Geosynthetic-encased stone column (GESC) technology for strengthening soft clay offers significant advantages in terms of cost-effectiveness, environmental sustainability, and engineering applicability. It is widely applied in treating soft foundations for railways, bridges, and embankments. This study evaluates the cyclic response of the geosynthetic-encased steel slag column (GESSC) composite foundation employing three-dimensional nonlinear finite element analysis. A numerical study is conducted to assess the cyclic response of floating GESSC considering the influence of key design variables, including cyclic load amplitude, loading frequency, geosynthetic encasement stiffness, and length-to-diameter ratio. Results show that both cyclic load amplitude and frequency affect the cumulative settlement and excess pore pressure within the GESSC foundation. Within specified limits, increasing the encasement stiffness and column length can significantly improve the GESSC load-bearing characteristics. The parametric study suggests an optimal geosynthetic encasement stiffness for the field prototype columns within the range of 4480–5760 kN/m and a critical steel slag column length of 10 times the column diameter.

Local scour at group of bridge piers founded in gravel bed in staggered arrangement

Local scour around bridge piers is the common cause of undermining of bridge foundation. Many researchers have studied local scour around bridge pier in finer sediment bed. The literature survey reveals a limited information is available on scour around a group of bridge piers with and without collar founded in gravel bed. Keeping this in view, an attempt is made to examine experimentally the efficacy of the collar around a group of three piers placed in a staggered triangular arrangement in the gravel bed of 3 mm effective size. The data on temporal variation of scour depth, scour hole characteristics, and areal extent of scour hole were collected. The collected experimental results infer very prominent information to the bridge engineers. The obtained results on equilibrium scour depth and areal extent of scour help in knowing the extent up to which bridge pier protection can be provided against scour. It is found that at longitudinal pier spacing (Z) equals to 8.45 times the pier diameter (b), the equilibrium scour depth at nose of the piers was maximum than that of at other pier spacing. At pier spacing Z/b > 8.45, the equilibrium scour depth at downstream pier without collar decreases with increasing pier spacing and reaches to minimum at Z/b = 40. At pier spacing 8.45 < Z/b < 10, the equilibrium scour depth at upstream pier without collar decreases because of decreasing effect of reinforcement and this effect disappears at pier spacing Z/b > 10. The present study reveals that bridge piers without collar became free of mutual interference effect on local scour at centre-to-centre (c/c) pier spacing of 60 times the pier diameter. It is worth mentioning that for piers with collar, the effect of mutual interference vanished at c/c longitudinal pier spacing of 20 times the pier diameter. The results show that additional shielding of collar makes the piers free from mutual interference effect at lesser spacing than the pier group without collar. This concludes that the present investigation is very useful when limited space is available between the existing and newly proposed bridges.

Prediction of Pier Scour Depth under Extreme Typhoon Storm Tide

The Western Pacific region is highly vulnerable to typhoon storm surge disasters, with localized erosion posing a particularly prominent issue for coastal marine structures. The prevalence of extreme typhoon storm surges poses a significant threat to the safety of engineering projects in these areas. In this study, a parameterized wind field model with precise calculation of wind speed was employed to establish a numerical model for typhoon storm tides. Based on the Western Pacific typhoon data from 1949 to 2023, hydraulic simulations were conducted for Hangzhou Bay, Xiangshan Port, and Yueqing Bay, revealing maximum flow velocities of 4.5 m/s, 1.95 m/s, and 2.09 m/s, respectively. These velocities exceeded the maximum possible tidal flow by 0.47–1.17 m/s. Additionally, using Sun’s velocity formula, the initiation flow velocities were calculated to be 1.85 m/s, 1.81 m/s, and 2.06 m/s for the aforementioned locations. Through localized erosion tests conducted around typical bridge piers and the subsequent application of similarity criteria, the maximum depth of localized erosion in the study area was determined to range from 2.16 m to 16.1 m, which corresponds to 1.1–2.3 times the scour caused by the maximum tidal flow scenario. A comparison of the erosion test results with calculations based on several formulas demonstrated that the scour prediction formula proposed by Sun exhibited the highest accuracy. This study supplements the understanding of the impact of typhoon storm surges on bridge pier erosion and provides a scientific basis for the design of bridge foundations.

Computational Simulation of Monopile Scour under Tidal Flow Considering Suspended Energy Dissipation

Local scour around bridge foundations significantly impacts the stability and safety of marine structures. The development of scour holes adjacent to the pile foundations of sea-crossing bridges, influenced by tidal currents, involves multidimensional physical fields, multiscale coupling, and complex variations in marine loads. However, experimental models alone are inadequate for investigating the underlying mechanisms. Numerical simulation, a critical tool for studying local scour processes, faces the challenge of accurately modeling sediment transport, particularly under tidal flow conditions near pile foundations. To solve this challenge, this research considers the effect of reciprocating flow on sediment shear as well as its characteristic dissipation based on the immersed boundary method, introduces a reciprocating flow dissipation mechanism, and adds a momentum exchange term between the fluid and the sediment to derive a new controlling equation; a new tidal flow localized scour solver is ultimately constructed, termed TidalflowFOAM. The solver effectively simulates complex flow conditions under tidal currents, extending the modeling capabilities to more realistic three-dimensional bridge scour scenarios under combined wave and current conditions. Validation through cases reported in the literature and a series of controlled experiments, encompassing varying depths, flow velocities, and pile diameters, demonstrates the solver’s proficiency in capturing post-vortex data and accurately reflecting the influence of key factors on scour depth. However, the fidelity of the simulated scour hole morphology under tidal flow conditions behind the piles requires enhancement. The proposed numerical model for tidal flow conditions has high solution accuracy and can guide practical engineering applications.

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.

Experimental study on wave-induced loads and nonlinear effects for pier-pile group foundations of sea-crossing bridges: Wave slamming and suction effect

Strong nonlinear effects, such as wave slamming, suction effects, and wave overtopping, may be induced during wave-bridge interaction. However, an accurate understanding of these nonlinear effects is still insufficient. This study comprehensively investigates the wave slamming and suction effects on pier-pile group foundations of sea-crossing bridges in a 1:50 scale laboratory experiment. Random and regular waves with different strengths are generated based on wave conditions at the bridge site. Five water depths with a 2 cm spacing are designed to simulate varying pile cap clearances. Various pile arrangements are also set up to explore the influence of piles. Results show that wave slamming is low-aeration and is triggered mainly on the cap bottom wall, whereas the wave action on the vertical wall of the pile cap is quasi-static. The suction effect is generally recorded in the quasi-static phase of pressures and depends on the water exit process and the wave crest height. Moreover, the pressure oscillation after the impact phase results from the flow separation and rotation at structure corners. The wave slamming enhances with the increasing wave frequency when the impact area is constant, otherwise, it depends on the impact area. On the cap bottom wall, the wave slamming on inter-pile areas is enhanced, but the suction effect is less affected by pile arrangements. The increase in pile cap clearances reduces vertical forces but has less effect on horizontal forces. Additionally, a sustained increase in the wave crest height may reduce the slamming force. An empirical method for predicting wave forces is finally proposed based on the water entry theory and experimental findings. This work enhances the physical understanding of nonlinear effects during wave-bridge interaction and aims to support the design of substructures for sea-crossing bridges.

The Redesign of the Ngadi Bridge Foundation Structure in Mojo District, Kediri Regency

The Redesign of the Ngadi Bridge Foundation Structure in Mojo District, Kediri Regency

Study on the influence of groundwater recharge on pile foundation of high-speed railway bridge

Study on the influence of groundwater recharge on pile foundation of high-speed railway bridge

Conditional seasonal markov-switching autoregressive model to simulate extreme events: Application to river flow

Extreme events have the potential to significantly impact transportation infrastructure performance. For example, in the case of bridges, climate change impacts the river discharge, hence scouring patterns, which in turn, affects the bridge foundation stability. Therefore, extreme events (river flow) forecasting is mandatory in bridge reliability analysis. This paper approaches this river flow forecasting problem by developing a Markov-Switching Autoregressive model coupled with a conditional hidden seasonal Markov component. In addition, the proposed model is also combined with the deep machine learning neural networks method to forecast river flow from a dataset or from simulations. The proposed method is illustrated by using realistic data: historic river flow values of the Thames River. The results indicate that the proposed model well represented the extreme events within the dataset. In terms of river flow forecasting, the results indicate that the forecasts improve when the training period changes from 20 years to 40 years.

Factors influencing suffusion-induced delayed displacement of river bridge piers

In recent years, local scour has occurred on the pier foundations of river bridges during heavy rain and river flooding, often resulting in bridge collapse and outflow. This study focused on the characteristic displacement, called “delayed displacement”, of the river bridge pier. The critical displacement of the piers was first observed several days after the flood when the train passed and not immediately after the flood. The authors hypothesized that one of the possible reasons for the delayed displacement is the suffusion of the supporting ground beneath the pier foundation during the flood, followed by a compressive behavior due to the collapse of the soil skeleton under repeated traffic loads. Accordingly, this study performed erosion tests simulating flood and cyclic loading tests simulating train passage using a triaxial test apparatus to check the validity of this hypothesis. In some test cases, suffusion without any deformation occurred in the erosion test but deformed in the cyclic loading test just after the erosion test. This behavior matches the behavior of delayed displacement. It was also suggested that the risk of the delayed displacement becomes high when the soil skeleton was assumed to primarily comprise fine particles, and the void ratio and hydraulic gradient were high. By contrast, when the soil skeleton was assumed to primarily comprise coarse particles, suffusion occurred in the erosion test, but did not deform in the subsequent cyclic loading test. Thus, the risk of delayed displacement is considered to be low when coarse particles are dominant. Furthermore, clear relationship between suffusion and the consequent reduction in soil stiffness cannot be observed. This result indicates that no significant change in the stiffness occur in the supporting ground of the pier foundation at the stage immediately before the delayed displacement. Thus, identifying the deterioration in the stability of the piers through impact loading test, which is based on the concept that local scour reduces the natural frequency of the bridge pier, is difficult.

Underwater fatigue behavior of cementitious mortar and a countermeasure using a water-dispersible polyurethane ether–Portland cement composite

The underwater fatigue behaviors of cementitious mortars are investigated with a focus on the mechanisms contributing to the deterioration of bridge foundations and possible countermeasures. This study analyzes the effects of water penetration during repetitive loading and unloading on the underwater fatigue lives of cementitious materials, highlighting the importance of considering dynamic water motion, in addition to the surface energy mechanism. Water penetration during underwater fatigue occurs even in water-saturated specimens, and water in- and egress within a few millimeters of the specimen surface can significantly reduce the fatigue life. This study proposes a novel approach using a water-dispersible polyurethane ether–Portland cement composite as a countermeasure to improve underwater fatigue resistance. Based on experimental analysis of fatigue in water and microstructural investigations of the composite, the presence of polyurethane compounds within the nano-to-micron-sized microstructures may mitigate water penetration and contribute to a corresponding increase in underwater fatigue life.

Influence of local scour on the dynamic response of bridges under barge collisions

The response assessment of bridges crossing navigable waterways under vessel collisions is commonly conducted assuming intact bridge models. However, local scour may occur at bridge foundations, which has been identified as one of the major hydraulic causes of bridge failures. Therefore, it is imperative to consider local scour in the design and analysis of bridges against vessel collisions. Many previous studies have focused on the bridge response under vessel collisions assuming deterministic scour depths with incremental values, without integrating a scour prediction modeling in the analysis. This work investigates the barge-bridge collisions in the presence of scour at pile foundations, by using empirical scour prediction models. The accuracy of each prediction model is evaluated using relevant laboratory test and field measurement records. Finite element (FE) models of a four-span continuous reinforced concrete (RC) bridge and a jumbo hopper barge are developed in LS-DYNA. The current study identifies the correlation between the upstream flow depth and the barge collision location in the analyses. Numerical results illustrate that both scour depth and collision location influence the displacement, shear force, and bending moment response of bridge piles. The struck bridge pier accommodates a considerably increased displacement with an increased scour depth, while the shear force and bending moment are primarily influenced by the collision location. The influence of scour on the barge-pier collision force is marginal. The maximum axial force in soil springs increases considerably with scour depth. The choice of scour prediction model shows a significant impact on the displacement, shear force, bending moment of piles, the displacement of struck pier, and the axial force of soil springs.