BRIDGE MONITORING AND PERFORMANCE SUBGROUP

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BRIDGE MONITORING AND PERFORMANCE SUBGROUP
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OBJECTIVES

• Determine structure performance
• Identify effects of preservatives
• Solutions for reflective cracking of asphalt
  surfacing

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SUB-GROUP FOCUS

• Which structures to monitor
• What properties to monitor
• Methods of monitoring
• Who will do the monitoring
• Where will the documents ultimately reside

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Subgroup Activities

• Established criteria to select existing bridges
  to monitor
• Contributed to Alaska timber bridge database
• Determined monitoring requirements
• Determined monitoring team qualifications
• Determined cost and equipment

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Subgroup Activities

• Determined that AWIT monitoring and performance
  program will need to be a graduate research
  project and/or a cooperative effort between the
  Forest Service and State DOT bridge inspection
  programs and university affiliated applied
  research.

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Field Monitoring Matrix for AK-WIT Highway Bridges
NDE Non-Destructive evaluation of individual
bridge components stress-wave and/or resistance
micro-drilling techniques MC Sampling of wood
moisture content measurements C documentation
of construction practices VC Visual condition
assessment of bridge components P Preservative
migration into environment (via wood, soil, and
water sampling) IWD Immunodiagnostic Wood Decay
Test kit used in conjunction with wood sampling
for preservative migration LT Conduct overall
bridge load test with static live load
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Summary of Field Personnel Training Requirements
Oversight of all monitoring activities provided
by a registered professional engineer.
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STILL TO DO

• Final Report
• Selection of existing bridges to monitor
• Find a repository for reports and findings
• Duration of monitoring program
• Final costs
• Funding
• Monitoring

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THOUGHTS FOR FUTURE STUDIES

• Durability of Alaska species
• Guardrail posts
• Design values for posts, beams, timbers

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MONITORING ACTIVITIES

• Tonka Alaska Yellow Cedar bridge stringers
• Lunch Creek Trail Bridge

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LUNCH CREEK TRAIL BRIDGE Constructed 2005 20 ft
long trail bridge Design by Forest Service,
Ketchikan Wood Technology Center, and Forest
Products Lab Owner Alaska State Parks Division
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Alaska Yellow Cedar Wood from Prince of Wales
Island Glulams manufactured by Ketchikan Wood
Technology Center to AITC standards Bridge
constructed by Ketchikan-Misty Ranger District
trail crew
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Finger joints in the glulam stringers
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• Design considerations for Tongass rainforest
  climate
• Spacers installed for air gap between rail posts
  and girders.
• Deck overhang to protect girders from rain

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Monitoring considerations Glulam piece from
manufacturing process is on site for future
destructive testing
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One piece of decking on each end is extra long
for future destructive testing
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