Barge Impact Research Articles

Dynamic Soil–Structure Interaction of Bridge Substructure Subject to Vessel Impact

The paper describes the in situ investigation, site stratigraphy, field monitoring, data reduction, and subsequent time-domain analysis of soil–structure interaction from a full scale vessel impact loading of a bridge pier at the St. George Island Causeway. The in situ investigation included standard penetration testing, electric cone, dilatometer, and pressuremeter testing to identify soil stratigraphy, engineering properties (strength and moduli), and axial and lateral static pile resistance (T–z, and P–y). Field instrumentation included soil total stress and pore pressure gauges in front of and behind the pile cap, a fully instrumented pile (strain gauges along length), dynamic load cells to monitor barge impact loads, and accelerometers to monitor pier accelerations, velocities, and displacements. Analyses of the field data reveal significant dynamic forces within the soil–structure system as a result of the duration and magnitude of the loading. Inertia from the piers, cap, and piles provide significant resistance in the early portion of the impact. However, postpeak inertia (i.e., pier deceleration) resulted in maximum deformations of the pier. Soil damping provided most of the resisting force at the peak barge loading, whereas static soil resistance dominated at the peak lateral displacement. Time-domain finite element analysis of an impact event employing viscous soil dashpots, nonlinear P–y and T–z springs with nonlinear beam, and shell elements for the pier, cap, and piles resulted in reasonable load displacement predictions.

One‐Dimensional Model for Multi‐Barge Flotillas Impacting Bridge Piers

Abstract: The serious consequence of barge‐bridge collisions necessitates the study of barge impact loadings on bridges. This article introduces an elastoplastic spring‐mass model for the analysis of multi‐barge flotillas colliding with bridge piers at zero angle of attack. The model accounts for the essential factors pertaining to barge/flotilla impacts, such as pier geometry and stiffness, and dynamic interaction between barges. A method to identify the elastoplastic behavior of barge crushing is also presented. The proposed method generates impact force time‐histories for a multitude of flotilla configurations in a matter of minutes, which is especially valuable in probabilistic analysis requiring many collision simulations. The results from this study are compatible with the respective impact time‐histories produced by exhaustive finite element simulations. A bridge pier impacted by a three‐barge and a 15‐barge flotilla is studied.

Simplified Dynamic Analysis of Barge Collision for Bridge Design

The AASHTO design provisions for barge impact on bridges spanning navigable waterways use a static force approach to determine structural demand on bridge piers. Recently, however, full-scale experimental dynamic tests of barge impact have indicated that consideration should also be given to additional forces generated from dynamic effects. Specifically, mass-related inertial forces generated by the superstructure of a bridge can restrain underlying pier columns and lead to dynamic amplification of column design forces. This paper presents an algorithm for performing simplified, coupled dynamic barge impact analysis for bridge structures. This type of analysis yields structural design forces, with dynamic amplifications included, on the basis of characteristics of the design impact condition (barge mass and speed). Results from the proposed simplified analysis method are validated using full-scale experimental test data and are compared with results obtained from full-resolution analyses for a variety of barge impact energies and bridge types.

Glancing-Blow Impact Forces by a Barge Train on a Lock Approach Wall

In 1993 Headquarters, U.S. Army Corps of Engineers, issued the first formal Corps-wide analysis procedure providing guidance for analyzing the effects of barge impact loading on navigation structures. The guidance was rescinded in 2001 due to concerns about the conservatism of the computed results for usual and unusual loadings and accuracy with shallow approach impact angles and direct head-on impact. This paper addresses the interpretation of full-scale, low-velocity, controlled barge train (15-barge) impact experiments conducted at the decommissioned Gallipolis Lock at Robert C. Byrd Lock and Dam, Gallipolis Ferry, W.V. Two sets of methodologies were used to interpret the barge-to-wall impact data: (1) the use of the equations of equilibrium combined with an assumed value for the coefficient of friction between the barge train and the stiff-to-rigid wall, and (2) the energy method. A simplified empirical correlation is presented to calculate the maximum impact force as a function of the linear momentum normal to the wall using forces measured during these full-scale impact experiments. This empirical correlation is the basis for new Corps guidance for calculating glancing-blow impact forces.

Full-Scale Experimental Measurement of Barge Impact Loads on Bridge Piers

Bridges that span navigable waterways must be designed to resist potential impact loads associated with barge or ship collisions. Despite this fact, few experimental data have been collected about the magnitude and nature of such loads. Vessel-impact components of bridge design specifications, such as the AASHTO bridge design provisions, are therefore based on limited experimental data. Recently, a bridge in the United States (Florida) was replaced with a new structure and thus afforded a unique opportunity to conduct full-scale barge impact tests on piers of the preexisting structure before it was demolished. Tests were conducted on two piers with fundamentally different types of foundation systems. Tests on one pier also were repeated in two structural configurations (with the superstructure present and then with it removed). In each test, instrumentation and high-speed data acquisition systems were used to quantify the dynamic loads generated during controlled collision events. Experimental procedures used during the tests are described, and selected test results are presented, including experimentally measured dynamic impact loads and associated barge deformations. Comparisons are then presented between experimentally collected data and the current AASHTO barge impact bridge design provisions.

Part 2: Design of Foundations and Structures: Full-Scale Experimental Measurement of Barge Impact Loads on Bridge Piers

Bridges that span navigable waterways must be designed to resist potential impact loads associated with barge or ship collisions. Despite this fact, few experimental data have been collected about the magnitude and nature of such loads. Vessel-impact components of bridge design specifications, such as the AASHTO bridge design provisions, are therefore based on limited experimental data. Recently, a bridge in the United States (Florida) was replaced with a new structure and thus afforded a unique opportunity to conduct full-scale barge impact tests on piers of the preexisting structure before it was demolished. Tests were conducted on two piers with fundamentally different types of foundation systems. Tests on one pier also were repeated in two structural configurations (with the superstructure present and then with it removed). In each test, instrumentation and high-speed data acquisition systems were used to quantify the dynamic loads generated during controlled collision events. Experimental procedures used during the tests are described, and selected test results are presented, including experimentally measured dynamic impact loads and associated barge deformations. Comparisons are then presented between experimentally collected data and the current AASHTO barge impact bridge design provisions.

Development of U.S. Army Corps of Engineers Engineering Guidance for the Barge Impact Design of Navigation Structures

U.S. Army Corps of Engineers (USACE) guidance, Engineering Technical Letter 1110-2-563, was developed for the design of navigation structures subject to barge impact loading. The new guidance was developed with the use of the results from full-scale experiments conducted under the Innovations for Navigation Projects Research and Development Program. An empirical impact force model was derived from the experimental data, and probabilistic procedures were developed to assist with the design and analysis of navigation structures for impact loads from transiting vessels. Uncertainties in loadings due to a wide range of events from both natural and human sources are crucial in the design of these critical structures. These uncertainties are defined in terms of the distributions for impact angles, velocities, and tow masses, as well as the need to account for loss of power and control events. The methods developed in the guidance for the design and analysis of these structures are focused on defining the return periods for the usual, unusual, and extreme loads for the navigation structures. An example of the probabilistic procedures developed in the guidance is highlighted for the design of an upper guide wall at a navigation project.

Quantifying Barge Collision Loads for Bridge Pier Design and Vulnerability Assessment

Designing bridge structures that cross barge-navigable waterways requires that consideration be given to the lateral loads that are imparted to bridge piers during barge collision events. Similarly, assessing the vulnerability of existing structures to barge impact loading, especially bridges that form critical components of high-volume transportation networks, requires that engineers have access to tools for both determining impact loading and assessing structural response. Results are presented from a comprehensive study being conducted to develop improved procedures for quantifying barge impact loads. To understand and characterize such loads better, high-resolution contact-impact finite element analysis techniques were employed to simulate barge impact conditions with varying pier configurations, barge types, and soil characteristics. Although such models permit detailed analysis of impact phenomena, they are generally not appropriate for use in routine design. For this reason, an intermediate-resolut...

Development of U.S. Army Corps of Engineers Engineering Guidance for the Barge Impact Design of Navigation Structures

U.S. Army Corps of Engineers (USACE) guidance, Engineering Technical Letter 1110-2-563, was developed for the design of navigation structures subject to barge impact loading. The new guidance was developed with the use of the results from full-scale experiments conducted under the Innovations for Navigation Projects Research and Development Program. An empirical impact force model was derived from the experimental data, and probabilistic procedures were developed to assist with the design and analysis of navigation structures for impact loads from transiting vessels. Uncertainties in loadings due to a wide range of events from both natural and human sources are crucial in the design of these critical structures. These uncertainties are defined in terms of the distributions for impact angles, velocities, and tow masses, as well as the need to account for loss of power and control events. The methods developed in the guidance for the design and analysis of these structures are focused on defining the return periods for the usual, unusual, and extreme loads for the navigation structures. An example of the probabilistic procedures developed in the guidance is highlighted for the design of an upper guide wall at a navigation project.

Prediction of Pier Response to Barge Impacts with Design-Oriented Dynamic Finite Element Analysis

The loads imparted to bridge piers during barge impact events can be quantified and the structural responses that result from the application of such loads can be determined by using analytical procedures of varying degrees of complexity. At one extreme, sophisticated, nonlinear, dynamic finite element impact simulation techniques may be used to quantify the time variation of the dynamic loads generated during such collision events. At the other end of the spectrum are bridge design specifications with simple computational formulas for computing equivalent static loads for barge impact loading. An intermediate level—design-oriented dynamic finite element analysis technique—that is suitable for use in design practice with moderate computational resources is presented. The proposed method uses barge crush data—predetermined either experimentally or by using high-resolution finite element analysis—to link a design-oriented dynamic pier analysis program to a low-order, nonlinear barge model. For demonstration purposes, the method is implemented in a widely used commercial pier analysis program (FB-Pier). Results obtained from the proposed method, including both dynamic load predictions and structural response predictions, are compared with corresponding results obtained using high-resolution, finite element analyses for validation purposes.

Dynamic Finite Element Analysis of Vessel–Pier–Soil Interaction During Barge Impact Events

Current specifications for highway bridge design provide empirical relationships for computing lateral impact loads generated during barge collisions; however, these relationships are based on limited experimental data. To better understand and characterize such loads, dynamic finite element analysis techniques were employed to simulate vessel impact conditions never before tested experimentally. Descriptions of the methods used to model a hopper barge, bridge piers, and soil–structure interaction are given. Impact simulation results, including time histories of impact loads and barge deformations, are presented and compared with data generated using current bridge design specifications.

Static Finite-Element Analysis of Bridge Fenders for Barge Impact

Fender systems between channel piers are currently required by the U.S. Coast Guard for guidance of vessels under bridges. Because their only function is to guide the vessels through navigational channels under the bridges, these fender systems are not designed to withstand any lateral impact. The objective of this paper is to analyze the possibility of transforming bridge fender systems into pier protection against barge impact. A finite-element model of the fenders currently used by the Florida Department of Transportation was created using ANSYS software and subjected to a static load equivalent to the barge impact force. Because it may be uneconomical and impractical for fenders to be designed to withstand the total barge impact forces, they were also tested for 33% of such load. The results show that the fender systems currently used by the Florida Department of Transportation are too weak to function as bridge protection systems because they are unable to resist even 33% of the impact force without total destruction of the system.

Barge Collision Design of Highway Bridges

Method II of the American Association of State Highway and Transportation Officials (AASHTO) Guide Specification and Commentary for Vessel Collision Design of Highway Bridges focuses mainly on ship impact design. Consequently, the current specifications in Method II are limited mainly to bridges in maritime waterways. Bridges over inland waterways, though, are more susceptible to impact from barges. However, no inland waterway bridges are known to have been designed for barge impact using Method II due to the tremendous variation in flotilla sizes, barge types, and barge sizes. A method by which available barge and flotilla data may be utilized to develop the risk assessment procedures for vessel impact design problems in accordance with design Method II is presented. The methodologies presented in this paper are applicable to all navigable inland waterways in the United States and the world. For illustrative purposes, a design example is included which utilizes barge traffic data from rivers in Kentucky.