Barge Impact Research Articles

A mathematical framework for efficient predictions of dynamic processes of RC piers under barge collisions

The safety of bridge piers located in navigation waterways is often threatened by passing vessels nowadays. Empirical formulas such as those provided by AASHTO Guide Specification are currently extensively used to predict impact forces using equivalent static methods. However, the important dynamic effects involved in an impact event cannot be considered by a static analysis. Finite-element method is another strategy that is widely used in both engineering designs and scientific studies. Whilst finite-element method can well capture the main features involved in an impact event, it is expensive regarding both calculation time and computing resources. Simplified models are thus often needed to predict the dynamic impact processes efficiently. The coupled multi-degree-of-freedom model (CMM) proposed by the author previously is shown to be capable of predicting impact force time-histories and dynamic responses of pier columns efficiently with sufficient accuracy for a wide range of barge impact scenarios. However, empirical formulas for pre-estimating the values of the parameters introduced by CMM is still in great demand for practical applications. This paper aims to develop a mathematical framework enabling the computation of undetermined model parameters in terms of different input variables covering barge travelling information, barge bow stiffness and geometric information of an impacted pier column, and to thoroughly test the accuracy and efficiency of the proposed framework for realistic engineering applications pertaining to predictions of impact forces and dynamic response quantities of RC pier columns subjected to barge collisions.

Numerical Simulation of a Barge Impact on Bridges with Different Configurations of Pile Group Foundations

Three-dimensional finite element dynamic analyses were conducted to evaluate the effect of barge impact of different speeds on the lateral performance of three pile group (PG) configurations (vertical, battered, mixed) in terms of peak lateral displacement, peak shear force, lateral stiffness of PGs, and contribution of piles and pier columns to the total resisting force. The concrete material was modeled using the Concrete Damaged Plasticity model. The clay behavior was described using the Modified Cam Clay model; while the sand was modeled using the Drucker Prager model. The results showed that the vertical PG had the lowest lateral stiffness; while the battered and mixed PGs had closely larger stiffness, which allowed the development of larger impact force and pile cap displacement in vertical PG as compared to other PGs. The results of shear force showed that the foundation contributed up to 82% of the total lateral force in battered and mixed PGs. The results also showed that in vertical PG, the first row had slightly higher percentage of lateral force compared to other rows; while in battered PG, the load percentage was evenly distributed between rows. A contrast performance was observed for mixed PG. The results of bending moment (BM) showed that the piles in vertical PG had notably higher BM than the piles in other PGs due to larger pile cap displacement. In all PGs, the piles in the edge column had higher BM ratio, with the leading row (L) had the highest BM ratio (69–72%) in all PGs.

Finite element-based reliability analysis of RC bridge piers subjected to the combination of barge impact and blast loads

In this paper, the reliability analysis of a girder bridge pier is presented when exposed to the combinations of barge collision and blast loads based on the finite element (FE) simulations performed in LS-DYNA and the Monte Carlo algorithm performed in MATLAB. An improved reliability analysis approach is proposed for the bridge pier under combined loads using the residual dynamic resistance capacities of the impacted bridge pier when subjected to sequential blast loading rather than utilizing the static resistance capacities of the pier columns which are commonly employed by conventional fault tree analysis. In the first step of the proposed framework, the response surface method (RSM) using the Box-Behnken design (BBD) method is employed for fitting the structural response surfaces and the internal forces of the pier columns obtained from the FE simulations. Then, the reliability analysis results including the failure probability (Pf) and corresponding reliability index (β) are calculated using the Monte Carlo algorithm in MATLAB. Finally, the sensitivities of Pf and β to various barge collision and blast loading parameters are assessed, and fragility curves are plotted for the reliability analysis results. From the reliability analysis of the pier under combined loads, it is found that the failure probabilities of the pier resulting from the proposed method are greater than those from the conventional method based on the static capacities of the pier. Therefore, the conventional static-based method provides an unconservative approach and the residual dynamic capacities of the impacted and damaged pier should be considered under the sequential blast loading for reliability analysis of the pier under combined loads.

A simplified model of impact force time-history for bridge pier-barge collision

The formulas for estimating of the barge impact force in current codes and specifications are based on the standard European Barge. However, impact loads also depend on the size of barges. Additionally, the static analysis approach employed in current specifications cannot involve the dynamic effects generated by a barge collision. To this end, this study introduces a simplified model of impact force time-history for barges of different sizes. The finite element (FE) models of six barges with different sizes were developed, and then a series of numerical simulations was conducted to generate the benchmark impact force time-history curves, which is able to reflect the geometric effects of the collided object. The parameters in the proposed simplified model were then determined based on these benchmark curves. The efficacy of the proposed model is evaluated by a demonstration case study involving a girder bridge model and a cable-stayed bridge model. Additionally, the limitations of the current impact design provisions were evaluated. It is shown that the proposed simplified model of impact force time-history is capable of predicting the structural responses of bridges under barge collisions and the recommended values of model parameters are provided.

Dynamic behaviors of double-column RC bridge subjected to barge impact

This paper aims to study the dynamic responses and damage patterns of the prototype inland double-column RC bridge subjected to barge impact. Firstly, by utilizing a horizontal collision facility, a 1/5 scaled Jumbo Hopper (JH) barge bow repeated impact test with various impact velocities is carried out on three double-column RC bridge pier (DCBP) specimens. The impact force-time histories, crushing process of barge bow, and dynamic behaviors of both the impacted and adjacent piers are obtained and assessed. Then, by establishing the refined finite element (FE) models of the barge bow-DCBP collision, the present test is numerically simulated by adopting the FE program LS-DYNA. The corresponding FE analyses approach as well as the material models and parameters, are validated by comparing with the experimental impact forces, crush depths of barge bow, lateral displacement-time histories, and damage patterns of the DCBP specimens. Finally, the prototype barge-bridge collision is further studied with considering the material nonlinearity of the bridge pier and superstructure, soil-pile interactions, as well as the strain-rate effect. The impact process and damage pattern of bridge during collisions are discussed, and the influences of impact velocity, barge mass, and oblique angle on the dynamic behaviors of the prototype bridge are examined. It derives that, the impact velocity is more dominant on the peak impact force than the barge mass; the oblique barge impact amplifies the overall collapse risk of the bridge superstructure; the oblique angle has a remarkable aggravating effect on the induced damage level of bridge under identical impact kinetic energy.

Numerical evaluation of novel crashworthy devices for protection of RC piers subjected to vessel impact

The protection of bridge piers crossing navigation channels from the collisions of passing vessels is a critical issue nowadays, as vessel collision upon bridge piers has become one of the major threats to the safety of waterway bridges. This paper aims to develop a novel cost-effective crashworthy device, and to assess the effectiveness of the proposed device for protection of reinforcement concrete (RC) pier columns from vessel impact. The proposed protective device is comprised of a series of steel beams arranged in a frame-type manner with I-shaped cross-sections, where beam segments with reduced cross-sections are used to limit the plastic mechanism within certain structural components. The energy-dissipation capacity of the proposed device and its effectiveness for pier protection are thoroughly assessed by numerical approaches using general-purpose finite-element (FE) programs, where a barge is employed as the impacting vessel. Detailed non-linear FE models of the barge–device–pier system are developed and validated, and a parametric study is then conducted using the validated FE models with consideration of several important design parameters including barge impact velocity and geometric dimensions of the device. The numerical results show that the proposed device can absorb a large portion of impact energy during an impact event, which significantly reduces the magnitudes of impact forces transmitted to a protected RC pier column and attenuates the damage occurred to both the pier column and the impacting barge vessel. It is also found that the plastic deformation of the device can be effectively limited within the section-reduced beam segments whilst the remaining part remains elastic during impact, which would greatly facilitate the restoration of a damaged device after an impact event.

Impact force models for bridge under barge collisions

The impact force model is critical for the impact-resistant design of bridge piers and rapid assessment of bridge dynamic behaviors under barge impact, which is mainly studied in this paper. Firstly, the refined finite element models (FEMs) and the corresponding material model parameters of barge and pier, as well as the finite element analyses (FEA) approach for barge-bridge collision are validated through the impact test on the reduced-scale replicas of Jumbo Hopper (JH) barge bow and the flexible impactor lateral collision test on the RC column. Then, the prototype barge-bridge collision test is reproduced using the validated numerical algorithm and material model, by assessing the barge bow crushing process and depth, as well as the time histories of barge impact force and pier displacement. Furthermore, by considering the strain-rate of barge and bridge, surrounding water of the barge, soil-pile interaction, inertial effect of superstructure, as well as the nonlinear deformation of barge and bridge, the numerical simulations of total 54 prototype barge impact cases are performed with varied impact velocity and impact mass of barge traveling on inland waterways to assess the dynamic behaviors of both the barge and bridge. Finally, two analytical impact force models, i.e., triangular and multiple linear distributions, are developed based on the FEA results and further validated by another 9 randomly generated impact cases. The proposed impact force models can be directly applied in the rapid assessment of barge impact resistance of bridge piers without needing to build the complex barge models.

Design Loads and Pier Responses for Oblique Side Barge Impacts on Bridges

For bridges susceptible to barge collision, design provisions are typically utilized in determining collision scenarios and impact loading. Provisions in the United States require that bridges be designed to withstand two distinct collision events: direct (head-on) and glancing (e.g., oblique side). Head-on impact scenarios are represented using empirically determined static loads, and perpendicular impact loads are applied with magnitudes assumed equal to 50% of head-on impact loads. Subsequent to the formation of these provisions, numerous studies have identified the need to account for dynamic phenomena when designing bridges to resist vessel collision loads. Further, design-oriented computational techniques have been developed to characterize representative vessel–bridge collision scenarios, quantify dynamic barge impact loads, and compute time-varying bridge responses. While previous studies focused on head-on barge–bridge collision, the current study characterizes oblique side barge impact loading and resulting bridge response. Parameters such as barge flotilla configuration, impact angle, and location of impact initiation are investigated across a range of bridge models, leading to the identification of design-relevant oblique side impact scenarios. An alternative to the 50% design approach for oblique side impact scenarios involving the corners of barge bows is then proposed for assessing overall stability. The proposed approach incorporates dynamic phenomena and maintains agreement relative to more detailed analyses.

Method for Predicting Barge Impact Force Based on Nonlinear Spring Stiffness

Accurate prediction of barge impact force contributes greatly to the research of the soundness of the bridge under barge impact. Toward this end, the calculation method of barge impact force caused by ship-bridge collision is investigated in this study. Firstly, a comparative analysis for different energy conversion relationships is conducted via the high-precision finite element method (HPFEM) and the coupled vessel impact analysis (CVIA). A construction method of nonlinear spring stiffness (NSS) is proposed therefrom. Secondly, a high-precision finite element model is developed to simulate the barge-bridge collision under different barge masses and impact velocities. NSS under each condition is obtained, and the influences of barge mass and impact velocity on NSS are further discussed. An NSS model considering the effects of impact mass and impact velocity is proposed. Lastly, based on the NSS model, a prediction method of barge impact force is introduced. The results show that the impact mass has little influence on the peak value of NSS; however, the impact mass and impact velocity have a great influence on the tail of the NSS curve. According to the characteristics of NSS, four key control points can be extracted and NSS is simplified into a polyline model. The NSS model of the barge is obtained by nonlinear response surface fitting. The impact force can be predicted by combining the simplified NSS model and the proposed method in this study. The proposed method in this paper does not consider the pier stiffness; hence, it can be combined with NSS to quickly estimate the impact force, which can provide a design basis for the impact force in ship-bridge collision design. The rigid wall and a continuous rigid frame bridge impacted by the barge are studied; the results show that the proposed method can reasonably estimate the impact force.

Experimental and numerical assessment of scoured bridges with protective bonded steel plates against vessel impact

Water-crossing bridges are exposed to two threats in their service life – local scour and vessel impact. However, knowledge gaps exist towards understanding the behavior of water-crossing bridges when protected to resist such dual hazards, for instance, using bonded steel plates in bridge piers. Significant challenges are posed by modeling the nonlinear process of a complex vessel-bridge impact system under variable scour conditions. In this work, pendulum impact tests were conducted to simulate this process using ten scaled bridge pier-foundation system models with artificially introduced scour conditions. Based on the test results, an explicit finite-element (FE) program was developed to verify the material models, which were further adopted to develop the FE models for simulating a full-scale three-span steel-reinforced concrete bridge. The numerical vulnerability results reveal that the nominal damaging-impact velocity (NDIV) that leads to local structural damage in the bridge pier decreases as the scour depth increases. This paper further investigates the benefit of using bonded steel plates as a countermeasure against barge impact. Numerical results indicate that bonded steel plates can effectively reduce the local damage of the bridge pier under damaging NDIVs and various scour conditions.

Effects of Corrosion and Scouring on Barge Impact Fragility of Bridge Structures Considering Nonlinear Soil–Pile Interaction

Abstract This paper investigates the effects of corrosion and scouring on the barge impact fragility of bridge structures. A typical four-span continuous reinforced concrete (RC) bridge is selected...

Low-order model for impact load prediction on walls of navigation structures

As commercial waterway vessels such as groups of interconnected barges (i.e., barge flotillas) traverse navigable US waterways, collision incidents may occur on nearby structures. Navigation structures such as guide walls are therefore designed to resist loads that arise during collision events. Previous studies involving full-scale experimental impact testing and high-resolution finite element (FE) impact simulations revealed that barge impact loads on wall structures are transient (dynamic) and can be influenced by: flotilla impact-speed, mass, stiffness, and configuration, as well as impacted wall mass and stiffness. Empirical load prediction equations intended for use over wide ranging wall stiffness and mass characteristics often introduce excess conservatism into the design process. Accordingly, the present study was undertaken to develop a fast-running analysis methodology capable of accurately computing impact loads for navigation wall structures with varying mass and stiffness characteristics. Typical “run-times” required by the methodology are short enough so as to facilitate probabilistic design, wherein thousands of such analyses may be required. A standalone “low-order” dynamic analysis procedure was formulated to treat flotilla-wall systems in a simplified low-resolution manner, as contrasted to computationally-expensive high-resolution finite element analysis. The low-order procedure produces time-varying impact loads and wall displacements that are sufficiently accurate for design, yet requires drastically reduced computational resources in comparison to high-order approaches. Presented herein is derivation of an equation of motion for (low-order) barge flotilla impacts on rigid and flexible wall structures. Demonstration of suitable accuracy is achieved by comparing results obtained from the low-order procedure to those obtained from high-resolution impact simulations.

Reinforced concrete bridge structures under barge impacts: FE modeling, dynamic behaviors, and UHPFRC-based strengthening

Although some studies have been conducted to simulate the dynamic response of bridge piers under barge impact, several essential modeling issues (e.g., reasonably exerting permanent loads and simplifying FE models) are not well examined. Hence, high-resolution FE models are meticulously developed in this paper to simulate barge collisions with a typical four-span continuous girder bridge. Numerical results highlight the importance of the gravity load for barge impact-induced responses. A simplified bridge model is proposed to improve computational efficiency. The proposed simplified method is found to be more accurate than that of the one-pier two-span (OPTS) model. Also, it is observed that although the peak impact force increases with impact energy, the impact-induced displacement does not always increase. It is attributed to the fact that the spectral characteristics of the impact force-time history have a significant influence on the impact-induced responses. To improve the impact resistance, three strengthening methods based on ultra-high-performance fiber-reinforced concrete (UHPFRC) are investigated and compared. It is found that strengthening columns with two-end UHPFRC jackets is superior to other strengthening methods when considering cost-benefit ratio. Finally, a multi-objective optimization design procedure is presented for the UHPFRC-strengthened columns.

Damage identification of a single RC column subjected to barge impact based on optimization strategies

The safety of civil structures e.g. bridges and frame buildings are threatened by various inevitable hazards such as corrosion, fatigue and extreme loading e.g. earthquake, blast, impact. Such hazards may cause significant damage to structures and hence reduce their performance. This paper proposes two different strategies, i.e. the direct identification method which assumes that the information of loading which causes damage to a structure is not known and the indirect identification method which assumes that the loading causing structural damage is known to be generated by certain scenarios e.g. impact to identify the damage of civil structures after certain loading processes. Barge impact upon a single reinforced concrete (RC) column is considered in this paper to assess the prediction quality of the proposed strategies by comparing the identified damage quantities to the benchmark output data generated by an exact deformation analysis using the previously developed coupled multi-degree-of-freedom model (CMM). The proposed strategies show great potential for practical applications to damage identification of civil structures.

Nonlinear Dynamic Response and Assessment of Bridges under Barge Impact with Scour Depth Effects

AbstractThe lateral impact of barges is a vital load case for river-crossing bridges. In addition, flood-induced scour has been recognized as a leading cause of bridge failure. However, current bri...

Numerical evaluation of a novel crashworthy device for pier protection from barge impact

Bridges located in navigation waterways are susceptible to ship impact due to the large ship transportation volume nowadays. The development of effective energy-dissipation devices which can protect bridges from ship impact has drawn much attention in recent years. As a result, many different types of protective structures such as composite crashworthy devices have been developed, analyzed and applied in bridge engineering. However, such protective structures are often extremely costly and were difficult to repair after an impact event. This paper aims to develop a novel crashworthy device with a steel-frame configuration of potentially low production cost and to numerically evaluate its mechanical behavior to quantify its energy-dissipation capacity. The strategy of using reduced cross-sections for certain steel beams in the device is proposed to limit plastic mechanisms within certain structural components whilst ensuring that others remain elastic during impact. The effectiveness of this strategy is numerically evaluated based on the assumption that the reduced cross-sections are rigidly connected to form a continuous beam model. The proposed strategy would greatly facilitate the restoration process of such devices after an impact event by replacing only those structural components where plastic deformations have occurred.

Probabilistic Risk Assessment of Barge Impacts on Hurricane Floodwalls

AbstractHurricanes produce high winds and heavy precipitation, causing widespread damage to infrastructure in coastal areas. Throughout low-lying coastal cities such as New Orleans, Louisiana, a ne...

Lessons learned from six different structural health monitoring systems on highway bridges

Structural health monitoring has been utilized in numerous ways to investigate the performance and integrity of highway bridges. This paper highlights the use of six structural health monitoring systems, which were deployed to monitor distinct behaviors on six bridges in Kentucky. The structural health monitoring systems are as follows: (1) Over-height truck impact detection and monitoring on the I-64 over US 60 bridge, (2) Barge impact detection and monitoring on northbound US 41 over the Ohio River, (3) effectiveness of carbon fiber-reinforced polymer retrofit evaluation based on prestressed concrete I-girder crack movement on the I-65 elevated expressway in Louisville, (4) effect of thermal loads on bridge substructure evaluation on KY 100 over Trammel Creek, (5) thermal movement of expansion joints evaluation on eastbound I-24 over the Tennessee River, and (6) crack growth monitoring on steel floor beam on I-275 over the Ohio River. The deployment of the different structural health monitoring systems on Kentucky bridges has provided valuable insights on their planning, implementation, and maintenance, which can be applied on future structural health monitoring projects. While several of the projects have proved immensely successful, with some still being continuously monitored, others, due to numerous complications, have met with only limited success. The best return on investment was realized from structural health monitoring instrumentation that was focused and limited in scope. The successful structural health monitoring systems had continuous communication between all stakeholders during planning, implementation, and monitoring phases of the projects. Following implementation, the availability of contingency funds through the funding source, to replace/upgrade sensors and networking equipment and costs for reprogramming and reinstallation outside of regular maintenance costs, was also important for the structural health monitoring to be successful.

Parametric studies of pile-supported protective structures subjected to barge impact using simplified models

Independent protective structures supported by concrete-filled steel pipes have been widely used to protect bridge piers from vessel impact. In a high-energy impact scenario, such protective structures can absorb a large amount of energy through plastic deformation. Many previous studies are based on empirical static analysis which ignores important dynamic effects involved in an impact event. Finite-element simulation serves as an alternative approach which is commonly used for dynamic analysis of vessel collisions. However, finite-element simulation is expensive regarding both calculation time and computing resources. To conquer these problems, a simplified impact model considering soil-pile interactions and geometric non-linearity is developed in this paper based on the coupled multi-degree-of-freedom model previously proposed by the authors. The computational cost can be remarkably reduced by the simplified models. The influences of pile cross-section diameter, pipe thickness, pile length, free span of pile and soil properties on the energy dissipation capacity of pile-supported protective structures are investigated in this paper using the simplified models.

Evaluation of composite crashworthy device for pier protection against barge impact

Barge impact is a potential hazard to bridge piers located in navigation waterways. Pier protection against barge impact is of vital importance and thus protective structures of different types are currently extensively used in bridge designs. Glass fiber reinforced plastic (GFRP) is a kind of composite that has been widely used in the design of crashworthy devices for many bridges in China. However, many questions regarding the mechanical properties of this composite remain to be answered. In this paper, a series of material property experiments, i.e. tension, compression, bending and shear experiments, are conducted using GFRP samples, based on which the GFRP material parameters are determined. A quasi-static crushing experiment using a scaled composite cylinder is conducted to investigate the failure mechanism of GFRP, epoxy resin and polyurethane foams which comprise the composite section. In addition, a numerical model of the scaled composite cylinder is developed and validated using experimental results. The validated numerical model is then used to evaluate the effectiveness of a full-scale cylindrical crashworthy device with composite section subjected to barge impact.