做了一個水泥土組合樁，芯樁是鋼筋混凝土，被壓成了這樣，請問是什么原因，下面是命令流。

FINISH            

/CLEAR

/prep7

ET,1,solid65              !定義混泥土單元類型

ET,2,solid45              !定義水泥土單元類型

ET,3,link8                !定義鋼筋單元類型

keyopt,1,1,1              !不考慮形函數的附加項

keyopt,1,3,2              !無筋單元的壓碎后行為

keyopt,1,7,1              !考慮開裂后的應力釋放 

fck=40e6                 !C40混凝土抗壓強度標準值 

ftk=4e6                  !C40混凝土抗拉強度標準值  

!====================================

!混凝土本構模型定義

mp,ex,1,fck*0.19/0.0002   !定義混凝土單元材料抗壓彈性模量

mp,prxy,1,0.2             !定義混凝土單元材料泊松比

mp,dens,1,2500            !定義混凝土單元材料密度 

tb,concr,1

tbdata,,0.5,0.95,ftk,-1

tb,miso,1,,11

tbpt,,0.0002,fck*0.19

tbpt,,0.0004,fck*0.36

tbpt,,0.0006,fck*0.51

tbpt,,0.0008,fck*0.64

tbpt,,0.001,fck*0.75

tbpt,,0.0012,fck*0.84

tbpt,,0.0014,fck*0.91

tbpt,,0.0016,fck*0.96

tbpt,,0.0018,fck*0.99

tbpt,,0.002,fck

tbpt,,0.0033,fck

!=================================

!土定義

MP,EX,2,2.6e8            !定義土體單元材料抗壓彈性模量            

MP,PRXY,2,0.42            !定義土體單元材料泊松比 

MP,DENS,2,1900           !定義土體單元材料密度                                

!鋼筋本構模型定義

mp,ex,3,2.1e11

mp,prxy,3,0.3

tb,biso,3

tbdata,,360,0

!65單元實常數定義

r,1

pi=acos(-1)

r,2,0.025*0.025*pi/4

!樁模型建立

cyl4,,,0.8,,,90,21

cyl4,,,0.8,,1.1,90,21

circle,6,0.73,,,90,9

ldele,22,30,1

circle,1,0.73,,,90,9

ldele,22,30,1

L,15,25

L,16,26

L,17,27

L,18,28

L,19,29

L,20,30

L,21,31

L,22,32

L,23,33

L,24,34

vglue,all

nummrg,all

csys,1

lsel,s,loc,x,0.73

latt,3,2,3

lesize,all,0.3

lmesh,all

allsel

vsel,s,volume,,1

vatt,1,,1

vsel,s,volume,,3

vatt,2,,2

!=================

!劃分單元

allsel,all

esize,0.3

vmesh,all

/solu

asel,s,loc,x,1.1

da,all,all

csys,0

asel,s,loc,z,0

da,all,all

asel,s,loc,x,0

da,all,symm

asel,s,loc,y,0

da,all,symm

asel,s,loc,z,21

sfa,all,,pres,4.5e5

allsel,all

antype,static

acel,,,9.8

time,1

nsubst,100

cnvtol,u,,0.05

cnvtol,f,,0.05

outres,all,all

solve