2. Modeling A

2.1. Characteristics of modeling

The slope stability factor is calculated according to the Druck-Prager criterion. taking into account the infiltration of water into the ground. Before analyzing the stability, we therefore calculate the interstitial pressure field (PRE1) using the D_ PLAN_HS template. We use hydraulic boundary conditions in PRE1 that vary linearly. We will thus obtain the reasonable groundwater line despite negative interstitial pressure above the water line. We correct it in applying the Heaviside function afterwards to obtain the correct pressure field interstitial. This field PRE1 influences the stability of the slope. In fact, It generates underpressure under the slices of land which reduces the force of shear strength, making the slope less stable than the state without seepage. The interstitial pressure field is entered via the command variable PTOT of the field of materials, which is the input for macro command CALC_STAB_PENTE.

In this modeling, it is assumed that the fracture surface is circular and stability analysis using the simplified Bishop method (« METHODE_LEM =” BISHOP “``).

According to the preliminary study, the search area of the fracture surface is reduced by putting X1_ MINI = X1_ MAXI = 3.0 and X2_ MINI = X2_ MAXI = 13.2.

In order to speed up the calculation, we manually control the radius search band by putting Y_ MINI = 1.2 and Y_ MAXI = 1.6.

Since the limit coordinates of the tangential line are less than the ordinate of the foot of the slope, it is ensured that the assumed fracture surfaces are kinematically admissible.

2.2. Tested sizes and results

In the object evol_noli at the output of the macro-command we test the value of the sliding indicator (DX of field DEPL_NOEU) on the N391 node near the rupture surface and located in the part slippery. The result is shown in Tableau 1.

The values of the safety factors during the refinement of the mesh and the geometric parameters contained in the table at the output of the macro-command are also tested. The results are shown in the.

Table 1: Reference value at node N391 of the cham_defo (Modeling A)

Identification	Reference type	Reference value	Tolerance
X	NON_REGRESSION	1.0	0.001%

Table 2: Reference values of the FS table and of the geometric parameters of the circular fracture surface (Modeling A)