1 Presentation by: Jesse Conklin Group Members: J.P. Telemaque & Mike Milano First National Educational Competition on Predicting Progressive Collapse Resistance of Reinforced Concrete Structural Systems Level 1 – Undergraduate University of Massachusetts Amherst

2 Competition Outline Level 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 1/8 th Model Frame

4 Full Size 2-D Exterior Frame

5 1/8th Scale Model of 2-D Exterior Frame

6 SAP2000 1/8 th Scale Analytical Model

7 1/8 th 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 f’ c = 7,000 psi f y = 55 ksi, f u = 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 1 st Hinge – Reached Moment Capacity – Section face of middle column – both sides – Load = 1015 lbs Added pin at plastic hinge location – moment redistributed, checked deflection and curvature capacity 2 nd Hinge – Reached Moment Capacity – Section 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 1/8 th scale frame – Calculation of I c Collapse Load – XTract – 1/8 th scale cross-section moment- curvature analysis