# PM4Sand-Example 1
This example, provides an undrained confined direct simple shear test using one 4-node SSPQuadUP element and PM4Sand material model.
```tcl
wipe
set sigvo -101.3 set K0 0.5
set nu [expr $K0 / (1+$K0)]
set devDisp 0.10
set perm 1.0e-9
set Dr 0.35
set emax 0.8 set emin 0.5 set eInit [expr $emax - ($emax - $emin)*$Dr ]
set G0 476.0 set hpo 0.53 set rho 1.42
set damp 0.02 set omega1 0.2 set omega2 20.0 set a1 [expr 2.0*$damp/($omega1+$omega2)] set a0 [expr $a1*$omega1*$omega2]
model BasicBuilder -ndm 2 -ndf 3
node 1 0.0 0.0 node 2 1.0 0.0 node 3 1.0 1.0 node 4 0.0 1.0
fix 1 1 1 1 fix 2 1 1 1 fix 3 0 0 1 fix 4 0 0 1
equalDOF 3 4 1 2
nDMaterial PM4Sand 1 $Dr $G0 $hpo $rho 101.3 -1.00 $emax $emin 0.5 0.1 -1.0 -1.0 250.0 -1.00 33.0 $nu
element SSPquadUP 1 1 2 3 4 1 1.0 2.2e6 1.0 $perm $perm $eInit 1.0e-5
recorder Node -nodeRange 1 4 -time -file Cycdisp.out -dof 1 2 disp recorder Node -nodeRange 1 4 -time -file Cycpress.out -dof 3 vel recorder Element -ele 1 -time -file Cycstress.out stress recorder Element -ele 1 -time -file Cycstrain.out strain
constraints Transformation test NormDispIncr 1.0e-5 35 1 algorithm Newton numberer RCM system SparseGeneral integrator Newmark [expr 5.0 / 6.0] [expr 4.0 / 9.0] rayleigh $a0 $a1 0.0 0.0 analysis Transient
set pNode [expr $sigvo / 2.0] pattern Plain 1 {Series -time {0 100 1e10} -values {0 1 1} -factor 1} { load 3 0.0 $pNode 0.0 load 4 0.0 $pNode 0.0 } updateMaterialStage -material 1 -stage 0
analyze 100 1 set vDisp [nodeDisp 3 2] set ts1 "{Series -time {100 80000 1.0e10} -values {1.0 1.0 1.0} -factor 1}" eval "pattern Plain 2 $ts1 { sp 3 2 $vDisp sp 4 2 $vDisp }"
for {set x 1} {$x< 5} {incr x} { remove sp $x 3 }
analyze 25 1 puts "Removed drainage fixities."
updateMaterialStage -material 1 -stage 1 setParameter -value 0 -ele 1 FirstCall 1 analyze 25 1
puts "finished update fixties"
set ts2 "{Series -time {150 5150 1.0e10} -values {0.0 1.0 1.0} -factor 1}"
eval "pattern Plain 3 $ts2 { sp 3 1 $devDisp }"
setParameter -value 0.3 -ele 1 poissonRatio 1 analyze 5000 1
wipe ```