Built in Defects

• Area= 0.4 – 1.4 ft2
• Length 1 – 4 ft
• Necking reduces diameter to 22 in.
• Attached to rebar cager

NDT Access Tubes 

• 2-inch black iron NDT pipes in all shafts. 
• All shafts (except Shaft 3) had 4 access tubes.
• Shaft 3 had 3 access tubes.

Construction Defects 

• Soft Bottom
• Locations    
• Along the shaft length
• Multiple defects per shaft

Shaft Dimensions              

• Above Grade
  • Diameter = 36 Inches
  •   Length = 1– 3 ft
• Top Section
  • Diameter =  40 inches 
  • Length 20 ft
•   Bottom Section
  • Diameter =  36 inches
  • Length = 27 ft
•   TOTAL EMBEDED LENGTH = 47 ft
   

• Shaft 2 and 4
  • 5 levels of strain gages
  • 5 levels of telltales
  • Inclinometer casing
• Shaft 1, 3, and 5 
  • 2-5 levels of strain gages
  • 2 levels of telltales
  • Inclinometer casing
• Shaft 6
  • 5 levels of strain gages
  • Inclinometer casing 
• 2-inch black iron NDT pipes in all shafts