Vessel-bridge Collision Research Articles

A simplified method to consider hydrodynamic effect in oblique vessel-bridge collisions

The hydrodynamic effect in vessel-bridge collisions is either directly omitted or considered by the constant added mass (CAM) method in current studies. However, the high-resolution fluid-structure interaction (FSI) simulations indicate that the hydrodynamic effect plays an important role and cannot be adequately captured by the CAM method, particularly for oblique vessel-bridge collisions. On the other hand, the FSI simulations are time-consuming and have a high requirement for computational resources. For these reasons, a simplified analysis method was developed in this study to consider the hydrodynamic effect of vessel collision with bridge structures. In the developed method, mechanics of full 6-DoF ship maneuvering were established using several matrices to replace the explicit fluid domain of the FSI models, while the added mass method was adopted for the impacted pier to account for the hydrodynamic effect. Several collision scenarios were performed to compare the developed method with the FSI simulation and the CAM analysis. It was found that the proposed method is superior to the CAM method in terms of considering the hydrodynamic effect of vessel-bridge collisions, and its required computational cost can be significantly saved in comparison with the FSI model. From the perspective of calculation efficiency and accuracy, the proposed method is more suitable for the analysis and design of vessel-bridge collision in engineering practice than the FSI simulation and the CAM analysis.

Optimal Design Method for Vessel-Bridge Collision Based on Life-Cycle Theory

As structures crossing waterways, bridges are obstacles to vessels. Vessel-bridge collisions are inevitable. They not only involve the safety of vessel passage but also seriously affect the safe operation of bridges. Vessel-bridge collisions cause not only huge economic losses and casualties but also severe political and environmental losses. Vessel collision safety of existing and new bridges is one of the key technical problems that engineers and bridge managers must solve. Comprehensive consideration of vessel-bridge collision risk loss and structural performance in the design stage to achieve optimal cost over the life cycle is an important aspect of bridge design. Based on the current life-cycle design theory of engineering structures, this paper proposes a theoretical framework for vessel-bridge collision optimization design based on the life cycle, which includes three parts: vessel-bridge collision probability analysis, vessel-bridge collision vulnerability analysis, and vessel-bridge collision hazard. Taking the minimum cost of the bridge structure in the design service life period as the objective function, the optimization design model and design process of vessel-bridge collision based on whole life are established, and the key problems to be solved in each part are expounded.

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.

Impact Response Spectrum for Vessel-Bridge Collision Design

An equivalent static method is employed in calculating the impact response of vessel-bridge collisions, in which the dynamic characteristics of vessel-bridge collisions are ignored. An impact response spectrum for vessel-bridge design is proposed according to the principle of the earthquake response spectrum. The impact force time-histories are obtained through a numerical simulation method using finite element software. The relationship between the displacement amplification factor of the single-degree-of-freedom, period, and damping ratio under the excitation of impact force-time histories is obtained. The regularity of the displacement amplification is summarized. The characteristics of the vessel-bridge collision are given. The three-stage expression and specific application steps of the impact response spectrum for the design of vessel-bridge collision are provided.

Research on Bridge Structure Reliability Evaluation due to Vessels Collison Based on a Statistical Moment Method

Damage to bridge structures caused by vessel collision is a risk for bridges crossing water traffic routes. Therefore, safety around vessel collision of existing and planned bridges is one of the key technical problems that must be solved by engineering technicians and bridge managers. In the evaluation of the reliability of the bridge structure, the two aspects of vessel‐bridge collision force and structural resistance need to be considered. As there are many influencing parameters, the performance function is difficult to express by explicit function. This paper combines the moment method theory of structural reliability with finite element analysis and proposes a statistical moment method based on finite element analysis for the calculation of vessel‐bridge collision reliability, which solves the structural reliability problem with a nonlinear implicit performance function. According to the probability model based on current velocity, vessel velocity, and vessel collision tonnage, the estimate points in the standard normal space are converted into estimate points in the original state space through the Rosenblatt reverse transform. According to the estimate points in the original state space and the simplified dynamic load model of vessel‐bridge collision, the sample time‐history curve of random vessel‐bridge collision force is generated, the dynamic response of the bridge structure and the structural resistance of the bridge are calculated by establishing a finite element model, and the failure probability and reliability index of the bridge structure is calculated according to the fourth‐moment method. The statistical moment based on the finite element analysis is based on the finite element analysis and the moment method theory of structural reliability. The statistical moment of the limited performance function is calculated through a quite small amount of confirmatory finite element analysis, and the structural reliability index and failure probability are obtained. The method can be widely used in existing finite element analysis programs, greatly reducing the number of finite element analyses needed and improving the efficiency of structural reliability analysis.

Contrast of concrete dynamic constitutive models and simulation of vessel–bridge collision

Long-span bridges are constructed to cross oceans or rivers. With the rapid growth of waterway transportation, vessel–bridge collision incidents now occur in large numbers. In order to provide better understanding of the actual responses of bridge structures under impact load, vessel–bridge collisions were simulated using the non-linear finite-element method. Four commonly used dynamic constitutive models of concrete are described in this paper. Two impact tests (a rigid ball striking a target concrete wall and a hammer striking a reinforced concrete (RC) beam) were simulated using LS-Dyna. It was found that the RC damage model was more suitable for simulating the inelastic responses of cracks than the other three models. Based on the RC damage model, a typical bridge substructure subjected to a 1000 dead-weight-tonnage vessel collision was numerically simulated. An empirical formula for estimating the maximum impact force was then developed. This formula, which considers the reinforcement ratio and the vessel collision velocity, is suggested for practical vessel–bridge design. The proposed empirical formula and the equations recommended in codes from different countries were compared and it was found that the assessment of vessel collision force using the new formula is significantly improved.

ОЦІНКА РИЗИКІВ ТА РІВНЯ БЕЗПЕКИ ПРИ ЗІТКНЕННІ СУДНА З МОСТОМ

Bridges located on maritime and inland waterways are defenseless objects of infrastructure. One of their main features is the restriction of navigation channels, both vertically and horizontally, while navigation conditions may often be challenged by unpredictable currents and whirlpools. A great threat to people and vehicles on or near the structure occurred in case of a collision with ships and the destruction of bridges. Also, the consequences of such accidents are considerable financial expenses, where the cost of the bridge is usually much more than the cost of the vessel itself. The article addresses the issue of types, factors, causes and consequences of ship-bridge collision accidents. In spite of the modern level of development in the maritime industry such accidents occur annually, thus this problem is considered to be relevant nowadays. It is necessary to take measures to increase the safety of navigation in appropriate zones. The article presents the procedure for assessing the level of safety and the stages of identifying risks by determining the probability of a collision with bridge spans, supports and other structures, also identifying the most defenseless places, as well as the possible consequences of such damage (ship, city, environment). In addition, the paper considered the methods of protecting the bridge from collision and methods for reducing navigational risk. The results of the research are the development of the recommendations for avoiding possible dangers, mitigation of consequences, and reducing risks of vessel-bridge collision. It is proposed to form an “intellectual” zone in the navigable water area under the bridge to minimize the risks and consequences of an emergency. As a basic concept, it is recommended to use foreign and domestic experience in implementing the e-navigation strategy in the coastal zone and in the operational VTS areas. The article describes the implementation of modern marine technologies, such as virtual navigation aids and technologies of additional reality, which will significantly improve monitoring of the environment. Therefore, this introduction will reduce the risk of an emergency. Ensuring the full spectrum of available methods is necessary to determine risk and protect bridges from accidents. Such an approach shall allow not only to assess the risk of ship-bridge collision, but also to introduce additional active control elements during navigation in dangerous zones.

Study on the Probabilities of Vessel-Bridge Collision Considering the Influence of Existing Structures

In order to take the protection provided by existing structures into account, Protection Factor was introduced to revise the method for calculating collision probability in the Guide Specification for Vessel Collision Design of River-Crossing Bridges in Three Gorges Reservoir of Chongqing City. This revised method was utilized to calculate the annual frequency of collision and collapse of Urban Rail Transit Egongyan Bridge at present, in the short term and long term, considering the influence of the relative location of nearby existing bridge with the same span layout. The results indicate that when the existing bridge is assumed to be located upstream, the annual frequency of collision and collapse both decreases significantly. The revised method presented in this paper offers a reference for probability analysis of vessel collision for bridges protected by existing structures nearby.

Running Safety of Trains under Vessel-Bridge Collision

To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM). The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It is shown that the collision causes significant increase of the train’s lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient. The effect of the collision on the train’s vertical acceleration is much smaller. In addition, parametric studies with various train’s positions, ship tonnage, and train speed are performed. If the train is closer to the vessel-bridge collision position or the ship tonnage is larger, the train will be more dangerous. There is a relatively high probability of running danger at a low speed, resulting from longer stay of the train on the bridge. The train’s position, the ship tonnage, and the train speed must be considered when determining the most adverse conditions for the trains running on bridges under vessel-bridge collision.

Estimation of Vessel-Bridge Collision Probability for Complex Navigation Channels

In this paper, a model is proposed to evaluate vessel-bridge collision probability. A general mathematical model for navigation channels is suggested, which may be used for straight and meandering channels. The effects of waterway obstacles and water levels were taken into account in the proposed model. A definition and a judging criterion for an aberrant vessel to collide with a pier or an obstacle using geometry and kinematics were established. Finally, formulas were developed to estimate the vessel-bridge collision probability. The model proposed in this paper was applied to an existing bridge (Jiujiang Bridge) in China. The significances of meandering channels and waterway obstacles were noted.

Evaluation of a New FRP Fender System for Bridge Pier Protection against Vessel Collision

Physical protection systems typically are used to reduce vessel impact loads to nondestructive levels or redirect vessels away from bridge piers. An efficient physical protection system is critical for the safe operation of bridges and vessels. A new fender system, referred to as a floating fiber-reinforced plastic (FRP), can meet the design needs to protect both bridge piers and vessels. In addition, the floating FRP fender system, which is composed of FRP box modules filled with rows of FRP tubes, offers high-performance energy dissipation capabilities, modular construction, and easy replacement benefits. This paper focuses on a performance evaluation of this new fender system, used in a prestressed concrete bridge, by using a nonlinear explicit dynamic finite-element analysis program. The study included a vessel collision analysis with material properties calibrated by experimental data. The authors concluded that this new fender system has excellent energy-absorbing capabilities, significantly reduces collision forces, and increases collision duration imposed on the bridge pier and colliding vessel. Therefore, the new protection system is worthy of consideration for locations where a vessel-bridge collision is a concern.

Research on Risk Assessment of Vessel-Bridge Collision Accident in Inland Waterway

The Ship-Bridge collision accident risk evaluation model based on the analytic hierarchy process (AHP) was established and the weights of factors were confirmed. Qualitative and quantitative assessments of the Vessel-Bridge collision accident risk level were accomplished. The application results show that the possibility of Ship-Bridge collision accident could be evaluated by the security risk evaluation model based on the AHP. It can provide decision-making suggestions for the sitting of the new bridge and optimal evaluation for bridge type scheme.

Vessel-Bridge Collision Force Research on Ordinary Highway Bridge in Fujian Navigable River

Several methods had been provided to compute bridge collision force among domestic and abroad, the paper took Fujian Saijiang River as a example, and compared ship collision force calculated by different methods and chose the suitable collision force for the collapse of probability calculation. The American AASHTO guidelines and nonlinear finite element were practical to calculate collision force.

Risk Analysis of Vessel-Bridge Collision Based on AASHTO Method

One bridge in the southeast coast was cited as an example and the risk analysis theory was introduced into the study of vessel-bridge collision problem of the bridge. From the survey of the current situation development in the bridge site area and 5000 tons collision-prevention requirements, the annual probability of collapse of the bridge in the year 2020 is over the criterion by the AASHTO model algorithm. In accordance with the AASHTO acceptance criteria for vessel-bridge collision risk, the mentioned vessel collision risk of the bridge was not acceptable. In this paper, based on “m” method and FLAC3D program, the research on horizontal bearing capacity of pile group of one bridge in the southeast coast under vessel impact is performed, and the effects of the anchor is considered, which is significant for the risk analysis and bridge anti-collision study.

Probability Analysis and Risk Assessment about Vessel-Bridge Collision of Xihoumen Bridge

This document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.The vessel collision risk in the bridge operation period has become an acute problem that bridge engineering have to be faced, therefore, probability analysis and risk assessment about vessel-bridge collision in the bridge operation period is important. Combine with Zhoushan mainland-islands link project, using the AASHTO guide method and correction formula to calculate the probability about vessel collision with the pier 3 and to assess the risk about vessel-bridge collision of Xihoumen bridge in the operation period. The whole vessel-bridge collision risk assessment grade of Xihoumen bridge is grade two in the operation period, which is a low risk level. The operation manager need to pay attention to risk management and take preventive and control measures.

Dynamic Demand of Bridge Structure Subjected to Vessel Impact Using Simplified Interaction Model

Assessing the dynamic demand using general-purpose finite-element codes is not only low in efficiency, but also unaccepted in practical application due to the complicated nonlinear dynamical behaviors of vessel-bridge collision. In this paper, an alternative simplified interaction model is presented to evaluate the dynamic demand of bridge structure under vessel impact efficiently. In this method, ship motion is regarded as the motion of single degree of freedom, and ship-bow is modeled by a nonlinear spring element (only compression) connected to bridge structure. A quasi-static method is employed to obtain the nonlinear static relationships between impact forces and crush depths of ship-bow, and the effect of the height of pile cap is discussed. Based on two different approaches, the influence of strain-rate effect on impact force is taken into account to obtain the corresponding dynamic crush curves, which are developed for the proposed interaction model. Results show that the dynamic responses of bridge structures using the simplified interaction models are in good agreement with the general-purpose collision analyses, while the former computation efficiency is improved obviously.

Vessel-Bridge Collision Risk Analysis Based on Structural Reliability Theory

With the construction of bridges crossing inland waterways, it becomes vital to analyze the risk of vessel-bridge collision. In this paper, the limitation of the current vessel-bridge collision risk analysis approach recommended by the AASHTO code is addressed, and a new method is proposed based on method of moments of reliability theory. With consideration of the random characteristic of water level, impact angle, impact velocity and deadweight tonnage of vessels even with unknown distribution, the proposed method can reflect the risk level of vessel-bridge collision more accurately. The method can be also applied to other risk analysis of general building structures.