Bridge Management—Routine Maintenance: Recent Experience ...
Recent Guideline Changes 1 Recent AT Guideline Changes Existing Documents New Technical Documents...
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Transcript of Recent Guideline Changes 1 Recent AT Guideline Changes Existing Documents New Technical Documents...
Recent Guideline Changes1
Recent AT Guideline Changes
• Existing Documents
• New Technical Documents
• Bridge Structure Design Criteria
• Bridge Design Bulletins
• Bridge Best Practice Guidelines
• Roadside Design Guide
Recent Guideline Changes2
Existing Documents
• Hydrotechnical Design Guidelines
• Bridge Size Culvert Design Guidelines
• Culvert Sizing Considerations
• BPG # 7 – Spread Footing
Recent Guideline Changes3
New Technical Documents
• Context of Floods in Alberta
• Flood Envelope Curve Analysis
• AT Open Channel Flow Equation
• Alberta Rainfall Runoff Analysis
Recent Guideline Changes4
Bridge Structure Design Criteria
• Section 4e – Bridge Fills– No more CB6-2.3M22– Headslope tool – elliptical fill transition– Bridge Fill Width = Gross Width + 2m– Fill taper rate – max. 30:1
• Section 4b – Min. Bridge Grade– Target minimum = 1% (drainage)– Every effort for 0.5% min. grade
Recent Guideline Changes5
Bridge Design Bulletins
• BD # 5 – Retaining Walls near Rivers– Issues :
• Erosion - outflank/undermine• Failure – little warning, catastrophic• Repair – extensive, expensive• Inspection – specialized, systematic• Flexibility – accommodate future stages?
– Recommendation :• Consider Other Options• Design – RPW, piling, structure mod.
Recent Guideline Changes6
Bridge Best Practice Guidelines
• BPG # 9 – Rock Protection
• Typical details
• Why preferred option
• Bio – not at bridges
Recent Guideline Changes7
Roadside Design Guide
• Bridge Width (Section H5.4.1) :– Min. Bridge Clear Roadway = 9.0m– Match Road Design Clear Roadway– > 9000 AADT, shoulder = 3.0m– Max. shoulder width = 4.0m**– Urban – TAC shy distance (T3.1.6.4)
** Maximum for ring road structures is 3.5 m based on safety audit for AHD SW
Recent Guideline Changes8
Roadside Design Guide
Fig. H7.1 (Underpass Clearance)
Recent Guideline Changes9
Roadside Design Guide• Section H9.2 – Pedestrian/Cyclist
– Rural – shoulder OK– Systems Interchange – no pathway/sidewalks– Pathways ( TAC bidirectional multi-use min. ) –
4.2m wide on structure ( 3.0 plus shy dist. )– WOL + Sidewalk (2.5m wide) typical on low
speed/volume arterial bridges
*** NOTE: warrants for supplemental urban planned facilities beyond basic in urban areas currently under review
Recent Guideline Changes10
Future Guidelines/Clarifications
• Vertical clearances – Pedestrian Structures
• Parallel versus tapers on urban bridges• Use of retaining walls on high speed
roadway bridges• Maximum/minimum grades/crossfalls on
bridges• Combined effects of horizontal and vertical
geometry on ramp bridges