Homework - Reliability Analysis
In this assignment, you will use XSLOPE to perform reliability analyses on two slope stability problems using the built-in reliability analysis feature.
Start with the standard Excel input template:
Solve using the XSLOPE Google Colab notebook for stability analysis:
Problem 1 - Two-Layer Slope
Consider the following slope:
The material properties and associated standard deviations are as follows:
| Material | \(\gamma\) (pcf) | c (psf) | \(\phi\) (deg) | \(\sigma_\gamma\) (pcf) | \(\sigma_c\) (psf) | \(\sigma_\phi\) (deg) |
|---|---|---|---|---|---|---|
| Layer 1 | 125 | 100 | 30 | 9.1 | 20 | 4.5 |
| Layer 2 | 115 | 700 | 0 | 7.2 | 200 | - |
Do the following:
1) Build the slope model in the XSLOPE input template. Enter the material properties and the standard deviations (\(\sigma\)) for each parameter on the materials sheet.
2) Upload the input file and run the built-in reliability analysis.
3) Examine the results: \(F_{MLV}\), \(\sigma_F\), \(COV_F\), \(\beta_{LN}\), reliability (R), and probability of failure (Pf).
4) Save a copy of your Excel input template and a PNG of the reliability analysis results.
Problem 2 - Earth Dam
Revisit the earth dam problem from the XSLOPE Part 2 homework:
Use your existing Excel input file from the XSLOPE LEM Part 2 homework (with the piezometric line). The material properties and associated standard deviations are as follows:
| Material | \(\gamma\) (pcf) | c' (psf) | \(\phi\)' (deg) | \(\sigma_\gamma\) (pcf) | \(\sigma_{c'}\) (psf) | \(\sigma_{\phi'}\) (deg) |
|---|---|---|---|---|---|---|
| Shell | 125 | 0 | 34 | 7 | - | 6 |
| Core | 122 | 100 | 26 | 6 | 40 | 5 |
| Clay | 123 | 0 | 24 | 7 | - | 5 |
| Sand | 127 | 0 | 32 | 7 | - | 6 |
Do the following:
1) Add the standard deviations (\(\sigma\)) for each parameter on the materials sheet of your existing input file.
2) Upload the input file and run the built-in reliability analysis for the downstream side.
3) Examine the results: \(F_{MLV}\), \(\sigma_F\), \(COV_F\), \(\beta_{LN}\), reliability (R), and probability of failure (Pf).
4) Save a copy of your Excel input template and a PNG of the reliability analysis results.
Submission
Save a copy of your XSLOPE Excel input files and solution PNG files for both problems. Zip up your files into a single zip archive. Upload your zip archive via Learning Suite.
Grading Rubric
Total: 30 points
Problem 1: Two-Layer Slope (15 pts)
| Criteria | Points |
|---|---|
| Slope geometry and material properties entered correctly | 4 |
| Standard deviations entered correctly on materials sheet | 3 |
| Reliability analysis completed with correct results | 5 |
| Excel input file and results PNG submitted | 3 |
Problem 2: Earth Dam (15 pts)
| Criteria | Points |
|---|---|
| Existing earth dam model with piezometric line used | 3 |
| Standard deviations entered correctly on materials sheet | 4 |
| Reliability analysis completed for downstream side with correct results | 5 |
| Excel input file and results PNG submitted | 3 |