6. lvrm ch9 10 ukraine lwx-bridges
TRANSCRIPT
BRIDGESBRIDGES
Lan Zi Road, Lan Gao, China
Structural Capacity
Hydraulic Capacity
Safety
Scour ProtectionScour Protection
Failed during 6” Storm Failed during 6” Storm (50 Year Event)(50 Year Event)10 Killed10 Killed
New York- (1955- 1987)New York- (1955- 1987)150 Meters long- 5 Spans150 Meters long- 5 Spans
What is importantWhat is important
• Structural Capacity/Load • Hydraulic Capacity• Structure-Stream Compatibility/Adequate
Span• A Good Foundation• Scour Protection• Safety Features• Structure Inspection and Maintenance
LOW-WATER CROSSINGLOW-WATER CROSSING(FORDS, DRIFTS)(FORDS, DRIFTS)
Where to Use a Low-Water Crossing
• Flashy Flows/High Flow Fluctuation• Low Traffic Use• Delays are Acceptable/Non-critical Route• Broad/Flat Channels (Slightly Entrenched)• Debris Prone Channels• Grade Control Structures/Barriers• $$$-Least Expensive Alternative
Aspects of Low-Water Crossing Aspects of Low-Water Crossing DesignDesign
• **Structure-Site CompatibilityStructure-Site Compatibility• *Providing for Aquatic Organism Passage (AOP)*Providing for Aquatic Organism Passage (AOP)• Roadway and Site GeometryRoadway and Site Geometry• Site Hydrology-Design High and Low FlowsSite Hydrology-Design High and Low Flows• Hydraulic Design-Capacity, VelocitiesHydraulic Design-Capacity, Velocities• Scour and Bank ProtectionScour and Bank Protection• Driving Surface Structural DesignDriving Surface Structural Design• Traffic Control and SafetyTraffic Control and Safety• Materials SelectionMaterials Selection• BMPs for Erosion Control and Water QualityBMPs for Erosion Control and Water Quality
Structure-Site Compatibility
Providing for Aquatic Organism Passage
K. Clarkin
Problematic Designs
K.Clarkin
Roadway and Site GeometryRoadway and Site Geometry
Site Hydrology andSite Hydrology andHydraulic DesignHydraulic Design
Scour and Bank ProtectionScour and Bank Protection
Driving Surface Driving Surface Structural DesignStructural Design
K. Clarkin
Traffic Control and SafetyTraffic Control and Safety
USGS
Materials SelectionMaterials Selection
•Provide for AOP•Keep Stream Function
SUMMARY
•Design it Well!
TWarhol
http://fsweb.sdtdc.wo.fs.fed.us/pubs/pdf/LowWaterCrossings/
Roy Gu. 2003. Low water Crossing Study, FHWA, DTFH68-02-C-00024