Hydrodynamical Aspects of Pontoon Optimization for a Side-Anchored Floating Bridge

2017 ◽  
Author(s):  
Arnt G. Fredriksen ◽  
Mads F. Heiervang ◽  
Per N. Larsen ◽  
Pål G. Sandnes ◽  
Bernt Sørby ◽  
...  
Keyword(s):  
Longitudinal Axis ◽  
Design Principles ◽  
Bottom Flange ◽  
Elastic Structures ◽  
Wave Regime ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Floating Bridges ◽  
Span Width

Long floating bridges supported by pontoons with span-widths between 100m and 200m are discrete hydro-elastic structures with many critical eigenmodes. The response of the bridge girder is dominated by vertical eigenmodes and coupled horizontal modes (lateral) and rotational modes (about the longitudinal axis of the bridge girder). In this paper it is focused on design principles to reduce the response with regards to these eigenmodes. It is shown for a floating bridge with 200m span-width that by inserting a bottom flange the vertical eigenmodes can be lifted out of wind driven wave regime. It is also shown that selecting a pontoon length that give cancellation of excitation forces is beneficial, and that the geometrical shaping of the pontoon can be efficient to decrease the bridge response.

Hydrodynamical Aspects of Pontoon Optimization for a Side-Anchored Floating Bridge

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Arnt G. Fredriksen ◽  
Mads F. Heiervang ◽  
Per N. Larsen ◽  
Pål G. Sandnes ◽  
Bernt Sørby ◽  
...  
Keyword(s):  
Longitudinal Axis ◽  
Design Principles ◽  
Bottom Flange ◽  
Elastic Structures ◽  
Wave Regime ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Floating Bridges ◽  
Span Width

Long floating bridges supported by pontoons with span-widths between 100 m and 200 m are discrete hydro-elastic structures with many critical eigenmodes. The response of the bridge girder is dominated by vertical eigenmodes and coupled horizontal modes (lateral) and rotational modes (about the longitudinal axis of the bridge girder). This paper explores the design principles used to reduce the response with regards to these eigenmodes. It is shown for a floating bridge with 200 m span-width that by inserting a bottom flange the vertical eigenmodes can be lifted out of wind-driven wave regime. It is also shown that selecting a pontoon length that leads to cancelation of horizontal excitation forces is beneficial, and that the geometrical shaping of the pontoon can be efficient to decrease the bridge response.

scholarly journals Numerical Investigation of the Collision Damage and Residual Strength of a Floating Bridge Girder

2018 ◽  
Author(s):  
Yanyan Sha ◽  
Jørgen Amdahl ◽  
Cato Dørum ◽  
Zhaolong Yu
Keyword(s):  
Residual Strength ◽  
Strength Index ◽  
Damage Level ◽  
Critical Design ◽  
Collision Response ◽  
Parametric Studies ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Floating Bridges ◽  
Fast Prediction

For bridges across wide and deep waterways, fixed foundation structures are not possible to be built due to technical restrictions. Alternatively, pontoon supported floating bridges which do not require fixed foundations can be installed. As the girders of floating bridges may have a low clearance from the sea level, a critical design consideration is the capability of the girder to resist the collision of passing ships. It is hence important to investigate the collision response of the bridge girder and evaluate girder residual strength after the collision. In this paper, finite element (FE) models of a ship deckhouse and a floating bridge girder are established. The girder response to ship deckhouse collision is investigated through integrated numerical simulations. Parametric studies are conducted to compare the girder response for various girder designs and collision scenarios. The residual strength of the girder after in damaged condition is also investigated. Based on the numerical results, a residual strength index (RSI) is proposed for fast prediction of the girder damage level based on the absorbed energy.

scholarly journals Numerical Investigation of Wave-Frequency Pontoon Responses of a Floating Bridge Based on Model Test Results

2019 ◽  
Author(s):  
Yanlin Shao ◽  
Xu Xiang ◽  
Jianyu Liu
Keyword(s):  
Potential Flow ◽  
Scale Effects ◽  
Added Mass ◽  
Hydrodynamic Performance ◽  
Bottom Flange ◽  
Wave Excitation ◽  
Viscous Effects ◽  
Drag Coefficients ◽  
Floating Bridge ◽  
Bridge Girder

Abstract The wave-induced responses in the bridge girder of long floating bridges supported by pontoons are often dominated by the vertical modes, coupled horizontal modes and rotational modes about the longitudinal axis of the bridge girder. Pontoons with and without bottom flanges have been seen in recent floating bridge designs. Viscous flow separation around the sharp edges of the pontoon or the bottom flange may have strong influences on the hydrodynamic performance of the pontoon in terms of wave excitation, added mass and damping effects. Morison-type wave and current loads are normally included empirically in the early design phases to account for the viscous effects that cannot be covered by a potential-flow solution alone. Empirical drag coefficients and perhaps a correction to the potential-flow added mass are the inputs to such numerical models, which represents a part of the modelling uncertainties. Previous sensitivity studies using different drag coefficients in the ongoing Bjørnafjord floating bridge project in Norway indicate an influence up to 15% on the maximum vertical bending moment around the weak axis of the bridge girder. This paper contributes to the understanding of viscous effects on the hydrodynamic characteristics, e.g. the added mass, damping and wave excitation loads, of a floating bridge pontoon with and without keel plate. This is achieved by exploring existing model tests for floating bridge pontoons, performing 2D Computational Fluid Dynamic (CFD) analysis for pontoon cross sections and numerical calibration in a simplified frequency-domain model with linearized drag loads. Scale effects are also investigated through CFD analyses in model and full scales.

Design of floating bridge girders against accidental ship collision loads

2016 ◽  
Author(s):  
Yanyan Sha ◽  
Jørgen Amdahl
Keyword(s):  
Finite Element Models ◽  
Cruise Ship ◽  
Box Girder ◽  
Global Response ◽  
Ship Structure ◽  
Steel Box Girder ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Ship Collision ◽  
The Impact

The Norwegian Public Roads Administration is running a project “Ferry free coastal route E39” which includes replacing ferry crossings by bridges or tunnels across fjords in Western Norway. A floating bridge concept was proposed in the fjord-crossing project for Bjørnefjorden. As there are regular cruise routes passing by the bridge, it raises the concern for the consequences of accidental ship collision with the bridge girder. During the collision, the interactions between the bridge girder and the ship structure can be significant. Thus, in the design of the proposed bridge it is vital to evaluate the safety of the ship and the bridge. In this paper, detailed finite element models of a cruise ship and a steel box girder are developed. The impact scenarios and structural damages are studied. The results show that the proposed bridge girder design is generally safe to resist normal accidental ship collision loads. Numerical model of the whole bridge is also developed for further study of bridge global response subjected to ship collision load.

scholarly journals Control system for installation and position keeping of interconnected flexible floating bridge

2020 ◽  
pp. 002029402096855
Author(s):  
Dong-Hun Lee ◽  
Young-Bok Kim
Keyword(s):  
Control System ◽  
Simulation Analysis ◽  
System Model ◽  
Heavy Vehicles ◽  
State Estimator ◽  
Adverse Conditions ◽  
Control Framework ◽  
Floating Bridge ◽  
Floating Bridges ◽  
Bridge System

We propose an approach for floating bridge installation and operation. A floating bridge aims to carry heavy vehicles, trucks, and people over a body of water. However, bridge installation and operation are mainly performed by humans regardless of adverse conditions, such as active combat or disaster occurrence. For installing and operating floating bridges under such conditions, we devised a solution based on control system design and automatic installation. The floating bridge system is controlled and positioned by a power propulsion system that is attached to floating units of the bridge. An optimal control system based on state estimator, which is designed using a robust control framework, is applied to install and operate the bridge. A simulation analysis and experiments demonstrate the effectiveness of proposed method on a bridge system model comprising five floating units.

scholarly journals Comparative Study of the Floating Bridge Components

2021 ◽  
Vol 9 (VII) ◽  
pp. 258-262
Author(s):  
Prof. A. N. Humnabad
Keyword(s):  
Comparative Study ◽  
Limited Information ◽  
Different Types ◽  
Floating Bridge ◽  
Floating Bridges ◽  
Almost All ◽  
The Given

Floating bridge is a set of specialized shallow draft boats or floats hyperlink collectively to cross the river or canal or lake. With a track or deck most early floating bridge had been built for the features of the battle. There are numerous kinds of floating bridges relying on the conditions of the land and the type of barriers to cross. The principle behind floating bridge concept is the Archimedes’ principle of buoyancy. This study was made to review previous studies concerned about the floating bridges. Almost all the study concerned with floating bridge components and their suitability with the given condition. only limited information is available for floating bridges in many aspects. In this study we have covered the different types of pontoons, access to bridge, navigational openings, mooring systems, etc. are the most important parts of floating bridge.

Research on Multi-Level Fuzzy Evaluation for Safety of Floating Bridge in Complicated Engineering Environment

2013 ◽  
Vol 312 ◽  
pp. 928-933
Author(s):  
Yin Zhi Zhou ◽  
Jian Ping Wang
Keyword(s):  
Risk Factors ◽  
Evaluation Model ◽  
Safety Evaluation ◽  
Fuzzy Evaluation ◽  
Factors Affecting ◽  
Evaluation Indexes ◽  
Bridge Safety ◽  
Engineering Environment ◽  
Floating Bridge ◽  
Floating Bridges

In this paper, according to the characteristics such as great traffic throat role, obvious target and easy-to-expose, and poor protection ability of the floating bridges established in wartime and on the basis of comprehensively analyzing all risk factors affecting the floating bridges, a floating-bridge safety evaluation indexes system and a grey matter-element evaluation model 41 specific factors in the complex environment containing are established using enemy's threat, commanding decision, river environment, personnel's operation, equipment's quality, load passing and other risk factors encountered by the floating bridges as the primary indexes. Then, a safety evaluation is made in combination with a floating bridge setting-up case, thus drawing up a conclusion that the safety of this floating bridge is in a moderate state. Meanwhile, the main factors affecting the safety of the floating bridges are determined, thus providing certain references for the safety evaluation of other engineering.

Numerical Modeling and Dynamic Analysis of a Floating Bridge Subjected to Wind, Wave, and Current Loads

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Zhengshun Cheng ◽  
Zhen Gao ◽  
Torgeir Moan
Keyword(s):  
Axial Force ◽  
Wind Wave ◽  
Bending Moment ◽  
Wave Loads ◽  
Environmental Loads ◽  
Turbulent Wind ◽  
Load Effects ◽  
Floating Bridge ◽  
Bridge Girder ◽  
Sway Motion

Designing reliable and cost-effective floating bridges for wide and deep fjords is very challenging. The floating bridge is subjected to various environmental loads, such as wind, wave, and current loads. All these loads and associated load effects should be properly evaluated for ultimate limit state design check. In this study, the wind-, wave-, and current-induced load effects are comprehensively investigated for an end-anchored curved floating bridge, which was an early concept for crossing the Bjørnafjorden. The considered floating bridge is about 4600 m long and consists of a cable-stayed high bridge part and a pontoon-supported low bridge part. It also has a large number of eigen-modes, which might be excited by the environmental loads. Modeling of wind loads on the bridge girder is first studied, indicating that apart from aerodynamic drag force, aerodynamic lift and moment on the bridge girder should also be considered due to their significant contribution to axial force. Turbulent wind spectrum and spatial coherence play an important role and should also be properly determined. The sway motion, axial force, and strong axis bending moment of the bridge girder are mainly induced by wind loads, while the heave motion, weak axis bending moment, and torsional moment are mainly induced by wave loads. Turbulent wind can cause significant larger low-frequency eigen-mode resonant responses than the second-order difference frequency wave loads. Current loads mainly contribute damping and reduce the variations of sway motion, axial force, and strong axis bending moment.

scholarly journals Effect of Floating Bridges on Velocity Distribution

2019 ◽  
pp. 1-16
Author(s):  
Mohamed M. Ibrahim ◽  
Mohamed A. Hassan ◽  
Adnan D. Ghanim
Keyword(s):  
Sandy Soil ◽  
Water Depth ◽  
Clay Soil ◽  
Water Channel ◽  
Maximum Load ◽  
Treatment Method ◽  
Clay Soils ◽  
Floating Bridge ◽  
Floating Bridges ◽  
Soil Changes

To ensure the stability of the bottom under the floating bridges according to the worst conditions, our study aims to determine the height and width and bearing the floating bridge to ensure the safety of origin with a high security factor. Our study determines the amount of damage under the floating bridge to be treated by a treatment method. We have used a practical model for a water channel and standard dimensions cut by the floating bridge connecting the two ends of the channel and when studying the erosion under the floating bridges and the possibility of maintaining the floating bridges without damage to the structure and perimeter of the bridge (bridge width, maximum load, bridge height, water depth in the channel with a factor Security This study examines the effect of floating bridges on the bottom by designing a model of a channel with a floating bridge and selecting a variable earth and sand floor. We conducted one hundred and sixty-eight experiments to examine the five variables (water depth in the channel, bridge width, loads on the bridge, soil type) Bottom, flow). We observed the effect of these five variables on topography of the bottom of the floating bridge. Experiments were conducted without a bridge and we observed erosion after laying the bridge, we noticed the erosion and sediment that occurred before and below and after the floating bridge and the effect of the bridge on it. We observed the type of positive and inverse relations between the variables mentioned. We took the loads on the bridge, the width of the bridge, the depth of the water and the drainage with a safety factor, as well as ensuring that the appearance of the channel and maintain the geometry of the channel. We put floating loads on the floating bridge to see a load. We used several models to view the floating bridge and made the water depth in the channel change more than once. We also made three different discharges. Finally, we used two types of soil and we recorded the durability and the worst conditions. The effect discharge, by (100% .64%, 45%) The velocity in the sandy soil changes (100%, 42%,38%) and the velocity in clay soil changes (100%,59%,41%) As well as change the width of the bridge by (100%, 85%,71%)velocity changes by (80%,82%,100%) for sandy soil and the ratio of clay soil to (90%,95%,100%) As well as weight change by (100% ,83%,66%)the rate of velocity in the sandy soil to (100%,78%,61%) also change the velocity in clay soils to (100%,68%,62%) as well as depth change  (100%,87%,75%)The speed in the sandy soil changes to (50%,75%,100%)  and also changes in clay soils by (71%,78%,100%) Thus, we have a knowledge of the rates of change and the effect of each variable on velocity. Therefore, we can draw up a plan to address erosion and sedimentation in the watercourse. Moreover, identify the expected challenges of (overload, flooding, deterioration, foot and aging as well as the structural strength of the bridge gradually decreasing with the foot.

Design of Various Shear Connectors for Repair of Corroded Steel Girders with Ultra-High Performance Concrete

2019 ◽  
Vol 2673 (2) ◽  
pp. 521-530 ◽  
Author(s):  
Dominic Kruszewski ◽  
Arash E. Zaghi
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
The United States ◽  
Extensive Study ◽  
Bottom Flange ◽  
Load Path ◽  
Ultra High Performance Concrete ◽  
Shear Connectors ◽  
Repair Procedure ◽  
Bridge Girder

Corrosion accounts for approximately 20% of the structurally deficient bridges in the United States, causing a massive backlog of rehabilitation projects. The current repair procedure for corroded bridge girders is expensive, slow to implement, and necessitates complete closure of the bridge. Through an extensive study supported by the Connecticut Department of Transportation, a novel repair method has been developed to rapidly restore the strength of corroded bridge girder ends with minimal traffic interruption. First, shear connectors in the form of headed studs are welded on the uncorroded web plate above the bearing. Next, formwork is placed and ultra-high-performance concrete (UHPC) is cast down to the bottom flange. This creates an alternate load path around the section loss. Based on the experimental results, it may be concluded that the implementation of the repair reduces the strains on the web plate and strengthens the bridge girder, allowing it to surpass its original capacity. However, the success of the repair centers around the performance of the shear connectors. In addition to headed studs, threaded bars and UHPC dowels in perforated web were evaluated experimentally as alternative shear-transfer mechanisms. This paper presents the repair design objectives and considerations for a realistic girder end utilizing different shear connectors to demonstrate the flexibility and versatility of the repair. The details of the designs are illustrated to facilitate the transition of the research findings to practice.

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