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 REPORT This report is an archived publication and may contain dated technical, contact, and link information
 Publication Number:  FHWA-RD-01-113    Date:  October 2002
 Publication Number: FHWA-RD-01-113 Date: October 2002

# Back-Calculation of Layer Parameters for LTPP Test Sections, Volume II

Figure 32. Flow chart for the deflection basin and load-response characterization procedure

1. Read deflection data file. Go to Number 2

2. Is Deflection i> Deflection 1? If Yes, it is Type I; go to Number 10. If no, go to Number 3.

3. Is Deflection data i> Deflection data i-1? If Yes, it is Type III; go to Number 10. If no, go to Number 4.

4. Calculate Deflection i/Deflection 1. Go to Number 5.

5. Calculate slope between normalized deflections. Go to Number 6.

6. Is slope i > slope i+1 and slope i+1 < i+2 and slope i+2 > slope i+3? If yes, it is Type II; go to Number 10. If no, go to Number 7.

7. Is slope i < slope i+1 and slope i+1 > i+2 and slope i+2 < slope i+3? If yes, it is Type II; go to Number 10. If no, go to Number 8.

8. Is slope i <= 4slope i+1? If yes, it is Type II; go to Number 10. If no, go to Number 9.

9. Is slope i <= 0.15slope i+1? If yes, it is Type II; go to Number 10. If no, it is Typical; go to Number 10.

10. Perform regression between load and sensor 1 deflections. Go to Number 11.

11. Is R squared >= 0.99? If yes, go to Number 15. If no, go to Number 12.

12. Perform linear regression for two highest load levels. Go to Number 13.

13. Is -20mu <= intercept <= 20mu? If yes, it is Elastic. If no, go to Number 14.

14. Is intercept > 20 mu? If yes, it is Strain Hardening. If no, it is Strain Softening.

15. Is -10mu <= intercept <= 10 mu? If yes, it is Linear Elastic. If no, go to Number 16.

16. Is intercept > 10mu? If yes, it is Strain Hardening. If no, it is Strain Softening.

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