桩土接触分析问题（ansys)

我算的一个桩土的例题，结果是应力和位移不理想，例如y向的位移不对称，请教高手帮我看下！小弟在此先谢过了！！
代码如下：
/prep7
et,1,plane42
et,2,solid45
mp,ex,1,2.5e10
mp,nuxy,1,0.2
mp,dens,1,2500
mp,ex,2,2.5e8
mp,nuxy,2,0.4
mp,dens,2,2000
tb,dp,2
tbdata,1,19,32,30

rectng,0,1,0,8
rectng,1,5,0,6
rectng,0,5,0,-16

/pnum,area,1
/pnum,line,1
asel,s,,,2,3,1
aglue,all
numcmp,all
allsel
aplot

lsel,s,,,1,3,2
lesize,all,,,2
lsel,s,,,2,4,2
lesize,all,,,,16
amesh,1

lsel,s,,,6,8,2
lesize,all,0.5
lsel,s,,,5,7,2
lesize,all,0.5
amesh,2

lsel,s,,,11
lesize,all,0.5
lsel,s,,,12
lesize,all,0.5
lsel,s,,,10
lesize,all,0.5
lsel,s,,,9
lesize,all,0.5
amesh,3

extopt,esize,2,0,
extopt,aclear,1
type,2
mat,1
vext,1,,,,,-1

extopt,esize,2,0,
extopt,aclear,1
mat,2
vext,2,3,1,,,-1
allsel
/view,1,1,1,1
eplot

k,1001,5,6,-5
k,1002,5,0,-5
k,1003,5,-16,-5
l,18,1001
l,1001,1002
l,1002,17
l,1002,1003
l,1003,21
al,22,36,37,38
al,30,38,39,40

extopt,esize,8,0,
extopt,aclear,1
vext,19,20,1,-4
vplot
extopt,esize,2,0,
extopt,aclear,1
vext,21,26,5,-1

vsel,s,,,4,7,1
vplot
lsel,s,,,36,66,1
lesize,all,0.5
type,2
mat,2
vmesh,all
allsel

vsel,s,,,2,7,1
vplot
eslv,s
nslv,s,1
eplot
nummrg,all
numcmp,all
allsel
/pnum,area,1
/view,1,1,1,1
/ang,1
/pnum,mat,1,2
eplot

allsel
et,3,170
et,4,173
keyopt,4,9,0
keyopt,4,12,2
r,10
real,10

mp,mu,2,0.2
vsel,s,,,1
vplot
asel,s,,,4,6,1
aplot
cm,target,area

type,3
nsla,s,1
esurf,all
esel,s,type,,3
eplot
/psymb,esys,1
allsel

vsel,s,,,2,7,1
vplot
asel,s,,,13
asel,a,,,17
asel,a,,,31
aplot
cm,contact,area

type,4
nsla,s,1
esurf,all
esel,s,type,,4
eplot
/psymb,esys,1
allsel
gplot
save
finish

/solu
asel,s,loc,x,0
aplot
da,all,symm
asel,s,loc,x,5
da,all,all
aplot
asel,s,loc,z,0
da,all,symm
asel,s,loc,z,-5
da,all,all
asel,s,loc,y,-16
da,all,all
allsel

acel,0,9.8,0
nsel,s,loc,y,8
esln,s
eplot
sfe,all,3,pres,,500

antype,static
nlgeom,on
time,1
nsub,100
outres,all,all
allsel
solve
finish