## Soil Modelling in OpenSEES-Help!

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### Soil Modelling in OpenSEES-Help!

Hi,

I am new to OpenSEES and trying to model soil using Gazeta's springs and dampers. Right now I have written a small code to verify if the 2D soil model I am using is correct.

I defined two uniaxial materials, one elastic (for spring) and another viscous (for damper). Then I defined another uniaxial parallel material made of elastic and viscous material.

I define two uniaxial sections, one for axial for deformation, and one for torsion. (Axial force deformation for X & Y direction and torsion for rotation along Z direction).

Then I defined three zero length elements representing spring and dampers in each direction.

The code I wrote is inline, any suggestions would be highly appreciated. I have just assumed some spring and damper coefficients.

Code: Select all
`wipe;wipeAnalysis;model basic -ndm 2 -ndf 3; set u 0.0000000001;node 1 0. 0. -mass \$u \$u \$u;             node 2 0. 0. -mass \$u \$u \$u;  node 3 0. 10. -mass 1000. \$u \$u;      fix 1 1 1 1;                  fix 2 0 0 1;fix 3 0 0 0;geomTransf Linear 1;               uniaxialMaterial Elastic 1 30000.;       uniaxialMaterial Viscous 2 20000. 1.;uniaxialMaterial Parallel 3 1 2;section Uniaxial 1 3 P;section Uniaxial 2 3 T;  element zeroLengthSection 1 1 2 1 -orient 0 1 0 0 0 1; # Vertical Spring-Damperelement zeroLengthSection 2 1 2 1 -orient 1 0 0 0 1 0; # Horizontal Spring-Damperelement zeroLengthSection 3 1 2 2 -orient 0 0 1 0 1 0; # Rotational Spring-Damperelement elasticBeamColumn 4 2 3 100. 1000. 10000. 1; pattern Plain 1 Linear {load 3 100. 0. 100.}constraints Transformationnumberer RCMsystem BandGeneraltest NormDispIncr 1.0e-5 60algorithm Newtonintegrator DisplacementControl 3 1 0.1analysis Staticanalyze 10#Earthquake Analysissource ReadSMDFile.tcl;ReadSMDFile BM68elc.th BM68elc.acc dt;set accelSeries "Series -dt \$dt -filePath BM68elc.acc -factor 1";pattern UniformExcitation 2 1 -accel \$accelSeries;#rayleigh 0. 0. 0. [expr 2*0.02/pow([eigen 1],0.5)];constraints Plain;numberer RCM;system BandGeneral;test NormDispIncr 1.0e-8 10;algorithm Newton;integrator Newmark 0.5 0.25;analysis Transient;analyze 500 0.02;`

Thanks.
University of California, San Diego
saurabhp

Posts: 1
Joined: Tue Apr 08, 2008 2:15 pm
Location: UC, San Diego

Why don't you use the ShallowFoundationGen command...?