Tunnel Inspections and National Standards - PowerPoint PPT Presentation

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Tunnel Inspections and National Standards

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... support lightweight panels Mechanical anchors commonly used Existing Standards Manual contains no standards on design of tunnel ... Board Presentation ... – PowerPoint PPT presentation

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Title: Tunnel Inspections and National Standards


1
Tunnel Inspections and National Standards
2
Tunnel Inspections
  • No formal tunnel inspections were performed to
    the ceiling system (January 2003 July 2006)
  • Postaccident inspection revealed displaced anchors

3
Tunnel Inspections
4
Tunnel Inspections
  • Inspection Manual for Tunnels and Boat Structures
    November 2003
  • Inspection manual not used
  • Develop database
  • FHWA review of the manual
  • MTA training
  • Tunnel inspections conducted since the accident

5
Existing Guidance
  • 5 years for new tunnels and 2 years for older
    tunnels
  • National Bridge Inspection Program
  • Not to exceed 2 years

6
Tunnel Inspections
  • New tunnels are not immune to critical
    deficiencies
  • Had MTA inspected the suspended ceiling between
    November 2003 and July 2006, the anchor creep
    would likely have been detected

7
Tunnel Finishes Standards
  • Surveyed 9 tunnel authorities
  • Ceiling panel dimensions and weights
  • Anchorage systems used

8
Survey Results
  • Adhesive anchors seldom used to support ceiling
    panels
  • Rarely installed in pure tension
  • Typically support lightweight panels
  • Mechanical anchors commonly used

9
Existing Standards
  • Manual contains no standards on design of tunnel
    finishes
  • National standards should be developed

10
Summary
  • FHWA lacks legislative authority
  • Seek legislation authorizing a mandatory tunnel
    inspection program
  • Identify critical inspection elements and
    inspection frequency
  • Tunnel design manual ensures uniformity and safety

11
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