# Consolidation- pore pressure plot **URL:** \ **Category:** FLAC3D\ **Created:** [April 20, 2025, 5:23pm UTC](https://forum.itascainternational.com/t/consolidation-pore-pressure-plot/2046 "2025-04-20T17:23:33Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![sowmyaramanis](https://avatars.discourse-cdn.com/v4/letter/s/839c29/32.png) [@sowmyaramanis](https://forum.itascainternational.com/u/sowmyaramanis)\ **Post date:** [April 20, 2025, 5:23pm UTC](https://forum.itascainternational.com/t/consolidation-pore-pressure-plot/2046/1 "2025-04-20T17:23:33Z")
Dear Itasca Team, I am working on consolidation problem of the soft soil improved by columns. For the mc model and its properties, when I am solving for the initial undrained condition, I am getting negative pore pressure. But Ideally it has to be maximum positive pore pressure. I have attached my code along with this. Kindly let me know you opinion. I am sure all the property values are correct to my knowledge. Dat file: model new model large-strain off model title ‘uc2’ 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 6 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 617 range group ‘soil’ zone property density 629 range group ‘column’ zone attach by-face ; — mechanical model — zone cmodel assign m-c zone property bulk 36e5 shear 13e5 cohesion 20e3 friction 1 poisson 0.33 range group ‘soil’ zone property bulk 120e5 shear 46e5 cohesion 32e3 friction 10 poisson 0.33 range group ‘column’ 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” zone face apply stress-normal = -0.1e6 range position-y 10 ; — fluid flow model — zone fluid cmodel assign isotropic 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 — model solve convergence 1 model save ‘uc2\_initial’ ; — turn on fluid flow model — zone fluid property perm 1.62e-10 poro 0.76 range group ‘soil’ zone fluid property perm 4.04e-10 poro 0.76 range group ‘column’ ;zone fluid property perm-xx 3e-10 perm-yy 1e-10 perm-zz 3e-10 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 ‘pp1’ pore-pressure position (0,0,0) zone history name ‘pp2’ pore-pressure position (0,0,1.275) zone history name ‘disp1’ displacement-y position (0,10,0) zone history name ‘disp2’ displacement-y position (0,10,1.275) model solve fluid time-total 8.7e6 model save ‘uc2\_end’ ---
**Author:** ![dblanksma](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@dblanksma](https://forum.itascainternational.com/u/dblanksma)\ **Post date:** [April 24, 2025, 6:06pm UTC](https://forum.itascainternational.com/t/consolidation-pore-pressure-plot/2046/2 "2025-04-24T18:06:11Z")
Hello @sowmyaramanis, I believe this question was answer from [flac3dsupport@itascacg.com](mailto:flac3dsupport@itascacg.com). Could you verify this.