6. Illustrations and validations
Typical soil mechanics problems are analyzed next to illustrate and validate the program.
6.6. Flow
First, here is a little java animation which shows a coupled safety analysis for a a weight-dam (GEOS Ing. Conseils).
6.6.1 Steady-state flow : rectangular dam with toe drain
The simple flow problem is representative of many situation. Boundary
conditions to be imposed are : pore pressure on
1, no flow on
2,
3 and
4, seepage flow on
3. Material data are : Darcy coefficient k = 1 (isotropic),
water deadweight
w = 10.
Fig. 6.17 - Dam with toe drain
The streamlines are illustrated on figure 6.18.
Fig. 6.18 - Streamlines
6.6.2 Stability of a loaded earth slope, influence of rain on inflow
The stability of an earth slope with a toe drain is analyzed and the influence
of a rain inflow is illustrated. Geometry and load are defined in figure
6.20. Material data are specified as follows : specific weight
= 23.52, elastic modulus E = 100’457, Poisson’s ratio
= 0.3, cohesion C = 10 , friction angle
= 30°, void ratio e0 = 1, fluid bulk modulus
F = 1038, permeability k = 1, load F = 10,
inflow q = 0.01127. An initial state analysis is performed first which
defines the steady state flow pattern. The stability is analyzed next and
a safety factor of 1.6 is found, as compared to 1.7 in the
dry case. A rain flow is simulated next which leads to identify a further
decrease of the safety factor which reaches 1.4, approximately.
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DRY CASE: SF = 1.7
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UNDERGROUND FLOW: SF = 1.6
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RAIN INFLOW: SF = 1.4
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Table 6.8 - Stability of a loaded earth slope