David R. Cowan

Nonlinear analysis of barge crush behavior and its relationship to impact resistant bridge design

Abstract Bridge structures crossing navigable waterways must not only be designed to resist gravity, wind, and earthquake loads, but must also be capable of resisting ship and barge collision loads. Design specifications used both in the US and internationally employ empirical models of vessel crush behavior to produce codified procedures for computing equivalent static design loads due to vessel impact. In this paper, the ADINA finite element code is used to compute force-deformation relationships for several hopper barge crushing scenarios. Results obtained from the nonlinear finite element crush analyses are then compared to empirical crush models found in bridge design specifications.

Barge Bow Force-Deformation Relationships for Barge-Bridge Collision Analysis

The AASHTO specifications pertaining to bridge design for barge collision loads use a static impact force determination procedure. Incorporated within that static procedure is a force–deformation relationship that represents barge bow stiffness. Recently developed dynamic vessel collision analysis techniques, which include mass-related components of bridge response, also require the use of a force–deformation relationship (or crush curve) to model barge bow stiffness. Whether static or dynamic analysis techniques are used, the vessel crush curve largely governs impact forces and, therefore, plays a critical role in quantifying structural response to impact loads. The basis for the AASHTO crush curve is reviewed, and new crush curves are proposed on the basis of finite element crush simulations of multiple high-resolution barge bow models. The barge models developed for this study are based strictly on structural vessel plans obtained from U.S. barge manufacturers and consist of the two most common types of barges traversing U.S. inland waterways (hopper and tanker). Recommended crush curves are then proposed for use in barge–bridge collision analysis and design.

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.

Response-Spectrum Analysis for Barge Impacts on Bridge Structures

AbstractBridge structures that span navigable waterways are inherently at risk for barge collision incidents and therefore must be designed for impact loading. Current U.S. barge impact analysis procedures consist primarily of static load analysis methods that do not explicitly account for dynamic effects in barge–bridge collisions, and thus are not ideally suited to designing bridge structures to resist barge impacts. Therefore, the development of dynamic-analysis methods for estimating the responses of bridge structures to barge collisions is warranted. Dynamic-analysis procedures that use numerical time-integration techniques are capable of capturing pertinent dynamic effects but often yield voluminous amounts of time-varying results that must be post processed for use in design. In contrast, response-spectrum analysis (RSA) procedures are capable of directly producing maximum response parameters that are most pertinent to structural design. In this paper, an RSA procedure is proposed for use in barge ...

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 ...