Abstract
PURPOSES: The objective of this paper is to select the confidential intervals by utilizing the second moment reliability index(Hasofer andLind; 1974) related to the number of load applications to failure which explains the fatigue failure and rut depth that it indicates the permanentdeformation. By using Finite Element Method (FEM) Program, we can easily confirm the rut depth and number of load repetitions withoutPavement Design Procedures for generally designing pavement depths.
METHODS : In this study, the predictive models for the rut depth and the number of load repetitions to fatigue failure were used fordetermining the second moment reliability index ( ). From the case study results using KICTPAVE, the results of the rut depth and thenumber of load repetitions to fatigue failure were deducted by calculating the empirical predictive equations. Also, the confidential intervals forrut depth and number of load repetitions were selected from the results of the predictive models. To determine the second moment reliabilityindex, the spreadsheet method using Excel’s Solver was used.
RESULTS : From the case studies about pavement conditions, the results of stress, displacement and strain were different with depthconditions of layers and layer properties. In the clay soil conditions, the values of strain and stresses in the directly loaded sections are relativelygreater than other conditions. It indicates that the second moment reliability index is small and confidential intervals for rut depth and thenumber of load applications are narrow when we apply the clay soil conditions comparing to the applications of other soil conditions.
CONCLUSIONS : According to the results of the second moment reliability index and the confidential intervals, the minimum andmaximum values of reliability index indicate approximately 1.79 at Case 9 and 2.19 at Case 22. The broadest widths of confidential intervalsfor rut depth and the number of load repetitions are respectively occurred in Case 9 and Case 7.
METHODS : In this study, the predictive models for the rut depth and the number of load repetitions to fatigue failure were used fordetermining the second moment reliability index ( ). From the case study results using KICTPAVE, the results of the rut depth and thenumber of load repetitions to fatigue failure were deducted by calculating the empirical predictive equations. Also, the confidential intervals forrut depth and number of load repetitions were selected from the results of the predictive models. To determine the second moment reliabilityindex, the spreadsheet method using Excel’s Solver was used.
RESULTS : From the case studies about pavement conditions, the results of stress, displacement and strain were different with depthconditions of layers and layer properties. In the clay soil conditions, the values of strain and stresses in the directly loaded sections are relativelygreater than other conditions. It indicates that the second moment reliability index is small and confidential intervals for rut depth and thenumber of load applications are narrow when we apply the clay soil conditions comparing to the applications of other soil conditions.
CONCLUSIONS : According to the results of the second moment reliability index and the confidential intervals, the minimum andmaximum values of reliability index indicate approximately 1.79 at Case 9 and 2.19 at Case 22. The broadest widths of confidential intervalsfor rut depth and the number of load repetitions are respectively occurred in Case 9 and Case 7.
| Translated title of the contribution | A Study of Reliability of Predictive Models for Permanent Deformation and Fatigue Failure Related to Flexible Pavement Design |
|---|---|
| Original language | Korean |
| Pages (from-to) | 105-113 |
| Number of pages | 9 |
| Journal | 한국도로학회논문집 |
| Volume | 16 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 2014 |