Effect of trapped air on wave forces on coastal bridge superstructures

Recent hurricanes have caused significant damage to coastal bridges of southern US coastal areas along the Gulf of Mexico. Previous studies have identified trapped air between bridge girders as a significant factor in increasing wave uplift loads on coastal bridge superstructures. The objective of this study is to investigate and quantify this effect. A numerical parametric study is conducted to examine the influence of this trapped air effect on resultant wave forces under different wave conditions for a variety of bridge geometry. Numerical results show that the wave loads on a bridge deck superstructure are sensitive to the amount of trapped air between the bridge girders. The wave uplift force is found to be 57–88 %, on average, lower for a wide range of wave periods when the effect of the trapped air is neglected. In addition, the effectiveness of the presence of air vents in reducing the air pressure between girders and the wave forces is evaluated. Numerical results indicate that the vertical (uplift) wave forces acting on the bridge superstructures can be reduced by about 56 % on average using deck air vents. Numerical results of the computational analyses of the wave forces on coastal bridge superstructures are also compared to estimations of the wave force computed from design expressions in AASHTO. It is found that while AASHTO estimations of the horizontal wave force are reasonable, estimations of the vertical forces are less consistent and can vary from overly conservative for larger waves to underpredicting for smaller waves.

[1]  Masoud Hayatdavoodi,et al.  Experiments and calculations of cnoidal wave loads on a coastal-bridge deck with girders , 2015 .

[2]  Frederic Raichlen,et al.  WAVE STRUCTURE INTERACTION: ROLE OF ENTRAPPED AIR ON WAVE IMPACT AND UPLIFT FORCES , 2011 .

[3]  M. Azadbakht,et al.  Simulation and Estimation of Tsunami Loads on Bridge Superstructures , 2015 .

[4]  Mohsen Azadbakht,et al.  Tsunami Modeling, Fluid Load Simulation, and Validation Using Geospatial Field Data , 2014 .

[5]  Ayman M. Okeil,et al.  Survey of Short- and Medium-Span Bridge Damage Induced by Hurricane Katrina , 2008 .

[6]  Bo Meng,et al.  Computation of wave loads on the superstructures of coastal highway bridges , 2011 .

[7]  D. Max Sheppard,et al.  Wave Loading on Bridge Decks , 2009 .

[8]  Reginald DesRoches,et al.  Bridge Damage and Repair Costs from Hurricane Katrina , 2008 .

[9]  H. Ronald Riggs,et al.  Lessons from Hurricane Katrina Storm Surge on Bridges and Buildings , 2007 .

[10]  Masoud Hayatdavoodi,et al.  Experiments and Computations of Solitary-Wave Forces on a Coastal-Bridge Deck. Part II: Deck with Girders , 2014 .

[11]  D. Max Sheppard,et al.  Storm Surge and Wave Loading on Bridge Superstructures , 2009 .

[12]  Ian Robertson,et al.  Experimental Investigation on the Role of Entrapped Air on Solitary Wave Forces on a Coastal Bridge Deck , 2014 .

[13]  Giovanni Cuomo,et al.  Wave-in-deck loads on coastal bridges and the role of air , 2009 .

[14]  Christopher Higgins,et al.  Large-scale laboratory observations of wave forces on a highway bridge superstructure , 2011 .

[15]  M. Souli,et al.  Arbitrary Lagrangian-Eulerian and fluid-structure interaction : numerical simulation , 2010 .

[16]  Jiin-Jen Lee,et al.  COMPUTATIONAL FLUID DYNAMIC ANALYSIS OF HIGHWAY BRIDGES EXPOSED TO HURRICANE WAVES , 2012 .

[17]  John D. Fenton,et al.  A Fifth‐Order Stokes Theory for Steady Waves , 1985 .

[18]  Masoud Hayatdavoodi,et al.  Experiments and calculations of cnoidal wave loads on a flat plate in shallow-water , 2015 .

[19]  Mohsen Azadbakht,et al.  Estimation of Cascadia Local Tsunami Loads on Pacific Northwest Bridge Superstructures , 2016 .

[20]  Masoud Hayatdavoodi,et al.  Wave forces on a submerged horizontal plate - Part I: Theory and modelling , 2015 .

[21]  Masoud Hayatdavoodi,et al.  Wave forces on a submerged horizontal plate-Part II: Solitary and cnoidal waves , 2015 .

[22]  Mohsen Azadbakht,et al.  Case Study for Tsunami Design of Coastal Infrastructure: Spencer Creek Bridge, Oregon , 2015 .

[23]  Ian Robertson,et al.  CASE STUDY OF CONCRETE BRIDGE SUBJECTED TO HURRICANE STORM SURGE AND WAVE ACTION , 2011 .

[24]  Daniel T. Cox,et al.  Experimental Setup for a Large-Scale Bridge Superstructure Model Subjected to Waves , 2011 .

[25]  Masoud Hayatdavoodi,et al.  Experiments and computations of solitary-wave forces on a coastal-bridge deck. Part I: Flat Plate , 2014 .

[26]  Wenrui Huang,et al.  Numerical Modeling of Dynamic Wave Force Acting on Escambia Bay Bridge Deck during Hurricane Ivan , 2009 .