Presentation by:

1
First National Educational Competition
onPredicting Progressive Collapse Resistance of
Reinforced Concrete Structural Systems

• Presentation by
• Jesse Conklin
• Group Members
• J.P. Telemaque Mike Milano

Level 1 Undergraduate University of
Massachusetts Amherst
2
Competition OutlineLevel 1 Undergraduate

• 1/8 scale 2-D model of a RC frame with 3 stories
  and 4 bays
• 2 Step procedure
• Instantaneously removing the glass column at
  first floor in the center of the frame
• If the frame remained standing, the structure was
  tested with static loads only and tested until
  failure
• Predicted displacements and total static loading
  after instantaneous removal of center column

3
1/8th Model Frame
4
Full Size 2-D Exterior Frame
5
1/8th Scale Model of 2-D Exterior Frame
6
SAP2000 1/8th Scale Analytical Model
7
1/8th Scale Cross-sections
8
Maximum Deflection of Frame

• Used SAP2000 Analysis for Deflection
• Actual Results
• Maximum - .21
• Residual - .20
• Calculated Results
• Maximum - .15
• Residual - .08

9
Material Properties

• Dimensions of scaled model are 1/8 of full scale
  model
• Applied loads are 1/64 of full scale applied
  loading to maintain approximate equal amounts of
  stress as compared to full scale model
• fc 7,000 psi
• fy 55 ksi, fu 75 ksi

10
XTract

• Each cross section was modeled in XTract to
  determine moment-curvature behavior
• Ultimate moment values from XTract were compared
  to moment values from SAP2000 full size
  analytical model
• Confined concrete - Mander model

11
SAP2000 Full Size Analytical Model
12
Static Loading

• 1st Hinge Reached Moment Capacity
• Section B-B _at_ face of middle column both sides
• Load 1015 lbs
• Added pin at plastic hinge location moment
  redistributed, checked deflection and curvature
  capacity
• 2nd Hinge Reached Moment Capacity
• Section B-B _at_ 6 ft. from face of column B both
  sides
• FAILURE
• Load 1454 lbs
• Predicted Collapse Load 1454 lbs
• Actual Collapse Load 1800 lbs

13
Collapse
14
Predicting Collapse Improvements

• Deflection
• Correct dimensions of 1/8th scale frame
• Calculation of Ic
• Collapse Load
• XTract 1/8th scale cross-section
  moment-curvature analysis