1 why is special inspection good for us?. 2 brief history of testing and special inspection notable...
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Why Is Special Inspection Good For Us?
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• Brief history of testing and Special Inspection• Notable past failures• Notable present-day failures• Less dramatic, but more common failures
Agenda
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Materials Testing, A Brief History
• Post-Civil War: engineers identify the need to better understand physical properties
• 1870’s: Riehle Brothers manufacture compression testing machines
• 1880: Tinius Olsen invents the Little Giant universal testing machine
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Materials Testing, A Brief History
• 1898: American Society for Testing and Materials is formed to address frequent breaks in rail lines
• 1901: A1 standard on steel rails• 1909: first cement and concrete standards• 1920’s: first road and paving standards• 1930’s: first masonry standards• 1930’s: first soil standards
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Skyline Towers, Arlington, VA, 1973
• 14 people die• Caused by removal of
shoring before adequate concrete strength is reached
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Hartford Civic Center Roof Collapse, 1978
• Caused by design and construction changes
Space Frame Roof Detail
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Hartford Civic CenterAngle Connection Details
As Built
As Designed
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Kemper Arena Roof Collapse, Kansas City, 1979
• Caused by inadequate roof drains• Ponding water on roof• Miscalculated hanger bolt strengths
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Harbor Cay Condominiums, FL, 1981
• 11 People die• Engineering errors• Thin slabs• Improper rebar
placement
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Hyatt Regency Skywalk Collapse, Kansas City, 1981
• 114 people die• Caused by construction changes without
engineering review
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U.S. House Sub-Committee on Science and Technology
• 1982 studies structural failures• 1984 presents report of findings
• Need for improved communications during the construction process• Need for construction inspection
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L’Ambiance Plaza, Bridgeport, CT, 1987
• 28 people die• Stacked slab construction• Unknown exact cause
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and…..Special Inspections is Born
• 1988 Special Inspections adopted in BOCA• 2000 Chapter 17 of the IBC was created from the legacy
codes (UBC, BOCA, SBC)
+ + =
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IBC, Section 1704 – Special Inspections
• Required by code• Special Inspector must be qualified• Special Inspector must be approved by
the Building Official• Special Inspector must be hired by the
owner or his direct representative (such as SE or architect)
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World Trade Center Collapse, 2001
• 2,752 people die• Substandard fireproofing is a major contributor
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McGuire Apartments, Seattle, Built 2002
• Improperly sealed PT cables• Corroded cables, cracked
concrete, structural integrity of entire structure compromised
• Demolished in 2011
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I-35 Bridge CollapseMinneapolis, 2007• 13 people die• Under-designed gusset
plates• Weight from additional
2” deck concrete (>5 million lbs.)
• 578,000 lbs. construction equipment and materials
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Harmon Tower, Las Vegas
• “Completed” in 2008• Missing critical rebar• Reduced from 49 to 28
stories• Scheduled for demolition
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Block 7, Lotus Riverside, Shanghai, 2009
• Unsupported garage excavation
• Saturated soils
• 1 person dies
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Indiana State Fair Stage Collapse, 2011
• 7 people die• Insufficient wind support
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Masonry Problems
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Form Mistakes
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When Welds Go Bad
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More Masonry Problems
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Concrete Consolidation Problems
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So … Why is Special Inspection Required?
Because it saves time, money, … and lives.
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Thank You
Questions?
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