This presentation is mainly about the study of slope failure using FLAC 3D software. The authors believe that it will surely help especially 4th b tech guys who are interested in project related to slope stability. Thanks

1. By
Sayantan Chatterjee(511214007)
Gopal Karmakar(511214015)
Department of Mining Engineering,IIEST SHIBPUR

2.  Introduction
 Slope stability
 Types of failure
 Analysis using FLAC3D
 Development of FLAC model
 Programme to calculate FOS
 FOS using extruder pane
 Development of FLAC model
 Programme to calculate FOS
 Conclusion

3.  Need of slope stability.
 Reason behind Slope Failure.

5.  Sliding Plane must strike parallel or nearly
parallel to the slope face.
 Dip of the sliding plane < Dip of slope face.
 Dip of the sliding plane > Angle of internal
friction.
 Tension Crack inside the slope face.

7. Creation of model
Definition of edge points
Setting zone boundary
Initializing gravity
Assigning Mohr Columb property
Applying face velocity
Saving the model
Solve to initial equilibrium
Again solving the model
Calculating FOS of the model

8. PARAMETERS SYMBOL VALUE
Elastic Modulus E 14.0 MPa
Poisson’s ratio ν 0.3
Unit weight, γ 20.0 Kn/m3
Cohesion c 10 kPa
Friction angle, ϕ 30°
Dilation angle ψ 0.0
Tensile strength, σt 0.0
Normal strength σ 9.31 MPa
E =

9. model new
fish automatic-create off
model title 'Slope with complex surface profile'
; create model
zone create brick point 0 (0,0,0) point 1 (10,0,0) point 2 (0,1,0) point 3 (0,0,10) size (40,1,40)
zone create brick point 0 (10,0,0) point 1 (46,0,0) point 2 (10,1,0) point 3 (10,0,10) size (144,1,40)
zone create brick point 0 (10,0,10) point 1 (46,0,10) point 2(10,1,10) point 3 (16,0,16)
point 4 (46,1,10) point 5 (16,1,16) point 6 (46,0,16) point 7 (46,1,16)size (144,1,24)
zone create brick point 0 (16,0,16) point 1 (46,0,16) point 2 (16,1,16) point 3 (26,0,21)
point 4 (46,1,16) point 5 (26,1,21) point 6 (46,0,21) point 7 (46,1,21) size (144,1,20)
zone face skin ; Label model boundaries
; initialize gravity
model gravity 10
; assign Mohr Coulomb model and properties
zone cmodel assign mohr-coulomb
zone property density 2000.0 bulk 1.16667e7 she 5.38462e6 fric 30 cohesion 10000.0 ten 0.0
; boundary conditions
zone face apply velocity-normal 0 range group 'East' or 'West1'
zone face apply velocity-normal 0 range group 'North' or 'South'
zone face apply velocity (0,0,0) range group 'Bottom'
model save 'initial'
; Solve to initial equilibrium
model solve elastic ratio-local 5e-3
model save 'slope-1'
model factor-of-safety bracket 1.3 1.5 ratio-local 5e-3 filename 'FOS-slope‘

32.  In the first model FOS is 1.35
 In the second model FOS is 0.80
 So the first model is stable but the second
model is unstable as the FOS is less than 1.