3. Modeling A

3.1. Characteristics of modeling

We calculate the FS and locate the non-circular fracture surface using the Morgenstern-Price method of the CALC_STAB_PENTE macro command. Knowing that the fracture surface passes through the weak layer if \(\lambda ={c}_{2}/{c}_{1}\ll 1\), We define the areas to search for the points of the end of the fracture surface as being the ends of the weak layer on the slope profile, Let X1_ MINI = 1.8, X1_ MAXI = 2.4, X2_ MINI = 15.6 and X2_ MAXI = 16.2.

Note

Based on prior tests, algorithm EFWA finds the optimum in 10 iterations approximately. So, we’re taking some margin with « ITER_MAXI = 30 ».

The result of the critical surface divided into 5 slices is shown in fig3-modeleA.

3.2. Tested sizes and results

The safety factor is tested at the last refinement of the mesh. The results are shown in Tableau 2.

Table 2: FS reference values (Modeling A)

NUME_RAFF	Identification	Aster Result	Reference Value	Error
4	FS	0.481604	0.5	3.2%

Since algorithm EFWA is a probabilistic algorithm, it is normal to observe a slight deviation from the FS obtained. Therefore, the comparison accuracy is increased reasonably (10%).

3.3. Summary of results

The FS result from macro-order CALC_STAB_PENTE gives the difference of 3.2% compared to the reference solution. This proves the relevance of the result of the Morgenstern-Price method and the EFWA algorithm in CALC_STAB_PENTE.