soil-pile model

xletsios · Post by **xletsios** » Tue Sep 04, 2007 8:00 am

I tried to create a soil-pile model, having used 2D ElasticBeamColumn elements for the pile and Quad elements for the soil, considering the material behavior as PlainStrain2D.

At the beginning, if I use ndm-2 ndf-2, the OpenSees WARNING says: "invalid ndf :2, for plane problem need 3 -elasticBeamColumn" , and if I use ndm-2 ndf-3 it says: "model dimensions and/or nodal DOF not compatible with quad element". What should I do?

Does anyone have any simple soil-pile tcl scripts for opensees?

Thank you!

Best Regards,
Christos Letsios
xletsios@yahoo.gr

mebowers · Post by **mebowers** » Wed Sep 05, 2007 11:20 am

You must create your 2D 2DOF Soil mesh first. You probably will want to apply gravity for the soil before creating your pile. Then call up the 2D 3DOF model builder and create your pile. You may then use equalDOF command to connect pile (with 3DOF) to soil mesh (with 2DOF) in the x and y directions.

If you are using springs to model nonlinear Soil Structure Interaction, dummy nodes are required in 2DOF space. The dummy nodes are connected to soil via spring elements. The 2DOF dummy node is then slaved to pile nodes using equalDOF.

Hope this helps,
Matt Bowers
Clemson University

xletsios · Post by **xletsios** » Fri Sep 07, 2007 3:22 am

Dear Matt,

Thank you very much! You were really enlightening. It really worked this way.

If you also have any related (soil-pile) tcl scripts, I would be grateful to receive.

Thanks again!

Best regards,
Christos Letsios
xletsios@yahoo.gr