Hello. I am working on the consolidation analysis and soft soil improved by deep mixing columns.
While using the soft soil model for the soil, I am getting an error message saying “Initial mean pressure cannot be less than cohesion/tan(friction)”.
Can someone help me to resolve this error?
I have attached my code as well here below.
model new
model large-strain off
model title ‘Instantaneous pore pressures generated under an applied load’
model configure fluid
zone create cylinder point 0 (0,0,0) point 1 (1.275,0,0) point 2 (0,10,0) point 3 (0,0,1.275) size 8 10 4 group ‘soil’
zone group ‘column’ range cylinder end-1 (0 0 0) end-2 (0 10 0) radius 0.425
zone property density 15000
; — mechanical model —
zone cmodel assign m-c range group ‘column’
zone property young 112e6 poisson 0.3 cohesion 600e3 friction 25 range group ‘column’
zone cmodel assign soft-soil range group ‘soil’
zone property friction 21 cohesion 1e3 k-m 0.0095 l-m 0.095 poisson 0.3 range group ‘soil’
zone face skin
zone face apply velocity-z 0 range group ‘bottom’
zone face apply velocity-x 0 range group ‘west’
zone face apply velocity-x 0 range group ‘east’
zone face apply velocity-z 0 range group ‘east’
zone face apply velocity (0,0,0) range group “south”
;w/o ramp
zone face apply stress-normal = -0.1e6 range position-y 10
; — fluid flow model —
zone fluid cmodel assign anisotropic
zone gridpoint initialize fluid-modulus 9e8
; — pore pressure fixed at zero at the surface —
zone gridpoint fix pore-pressure 0 range position-y 10
; — settings —
model fluid active off
zone fluid fastflow on
; — timing —
[global t0 = time.clock/100]
model solve convergence 1
[(time.clock/100)-t0]
model save ‘SE_INST_14’
program return
model restore ‘SE_INST_14’
; — turn on fluid flow model —
zone fluid property perm-xx 3e-11 perm-yy 1e-11 perm-zz 3e-11 range group ‘soil’
zone fluid property perm-xx 3e-9 perm-yy 1e-9 perm-zz 3e-9 range group ‘column’
model fluid active on
zone gridpoint initialize velocity (0,0,0)
zone gridpoint initialize displacement (0,0,0)
; — set mechanical limits —
model mechanical substep 100
model mechanical follower on
model fluid substep 10
; — histories —
model history fluid time-total
zone history name ‘column_pp’ pore-pressure position (0,0,0)
zone history name ‘soil_pp’ pore-pressure position (0,0,1.275)
zone history name ‘model_centre_pp’ pore-pressure position (0.5,0,0.5)
zone history name ‘centre_of_bottom_pp’ pore-pressure position (0,0,0.5)
zone history name ‘column_disp’ displacement-y position (0,10,0)
zone history name ‘soil_disp’ displacement-y position (0,10,1.275)
zone history name ‘model_centre_disp’ displacement-y position (0.5,10,0.5)
zone history name ‘centre_of_bottom_disp’ displacement-y position (0,10,0.5)
; — solve to 6,000,000 sec —
[global t0 = time.clock/100]
model solve fluid time-total 6e6 or mechanical convergence 10
[(time.clock/100)-t0]
model save ‘SE_END_14’
program return