本人模拟一个实例工程，
命令流如下：
new
;=============土层单元===============
group soil1 range z 57.5 60
group soil2 range z 54.5 57.5
group soil3 range z 51.5 54.5
group soil4 range z 43.5 51.5
group soil5 range z 37.5 43.5
group soil6 range z 31.5 37.5
group soil7 range z 21.5 31.5
group soil8 range z 0 21.5
group exc1 range x 0 30 y 0 2 z 60 54.9
group exc2 range x 0 30 y 0 2 z 54.9 52.2
group exc3 range x 0 30 y 0 2 z 52.2 49.5
group exc4 range x 0 30 y 0 2 z 49.5 46.8
group exc5 range x 0 30 y 0 2 z 46.8 44.1
group exc6 range x 0 30 y 0 2 z 44.1 41.4
group exc7 range x 0 30 y 0 2 z 41.4 40
;===============创建桩体=================
gen zone brick p0 30.8 0 87 p1 30.8 0.5 87 p2 30.8 0 61 p3 30 0 87 & size 8 5 26
gen zone brick p0 30.8 0.5 87 p1 30.8 1.4 87 p2 30.8 0.5 61 p3 30 0.5 87 & size 8 9 26
gen zone brick p0 30.8 1.4 87 p1 30.8 2 87 p2 30.8 1.4 61 p3 30 1.4 87 & size 8 6 26
group pile id=1 ran x 30 30.8 y 0 0.5 z 61 87
group pile id=2 ran x 30 30.8 y 0.5 1.4 z 61 87
group pile id=3 ran x 30 30.8 y 1.4 2 z 61 87
ini z add -31.5 ran group pile
;=================连接面的建立===============
interface 1 face ran x 30 30.8 y 0.5 z 29.5 55.5
interface 1 face ran x 30 30.8 y 1.4 z 29.5 55.5
interface 2 face ran x 30 y 0 2 z 29.5 55.5
interface 2 face ran x 30.8 y 0 2 z 29.5 55.5
interface 3 face ran x 30 30.8 y 0 2 z 29.5
int 1 prop ks 3e9 kn 3e9 fric 16.5 cohesion 15e3 dilation 0 tension 2e10
int 2 prop ks 2e9 kn 2e9 fric 10.8 cohesion 11.2e3 dilation 0 tension 1e10
int 3 prop ks 2e9 kn 2e9 fric 10.8 cohesion 7.04e3 dilation 0 tension 1e10
;==================土体和桩体参数=================
model mohr
prop bulk 6.90e6 shear 2.4e6 fric 13.5 cohesion 8.50e3 dilation 0 tension 1e10 density 1880 range z 0 21.5
prop bulk 5.30e6 shear 1.8e6 fric 10.3 cohesion 10.7e3 dilation 0 tension 1e10 density 1910 range z 21.5 31.5
prop bulk 6.10e6 shear 2.0e6 fric 13.3 cohesion 16.3e3 dilation 0 tension 1e10 density 1980 range z 31.5 37.5
prop bulk 6.4e7 shear 4.77e6 fric 14.4 cohesion 31.8e3 dilation 0 tension 1e10 density 2080 range z 37.5 43.5
prop bulk 3.30e6 shear 2.5e6 fric 13.5 cohesion 16.4e3 dilation 0 tension 1e10 density 1980 range z 43.5 51.5
prop bulk 3.0e7 shear 2.2e6 fric 10.4 cohesion 10.8e3 dilation 0 tension 1e10 density 1920 range z 51.5 54.5
prop bulk 4.0e7 shear 2.97e6 fric 13.5 cohesion 8.5e3 dilation 0 tension 1e10 density 1880 range z 54.5 57.5
prop bulk 2.0e7 shear 1.52e6 fric 16.5 cohesion 19e3 dilation 0 tension 1e10 density 1900 range z 57.5 60
def ini_szz
_grad=-1880*(-9.81)
_szz1=-_grad*(60-57.5)
_szz0=-_grad*60
command
ini szz add _szz0 grad 0 0 _grad range z 57.5 60
ini szz add _szz1 range z 0 60
end_command
_grad=-1910*(-9.81)
_szz1=-_grad*(57.5-54.5)
_szz0=-_grad*36.5
command
ini szz add _szz0 grad 0 0 _grad range z 54.5 57.5
ini szz add _szz1 range z 0 54.5
end_command
_grad=-1980*(-9.81)
_szz1=-_grad*(54.5-51.5)
_szz0=-_grad*51.5
command
ini szz add _szz0 grad 0 0 _grad range z 51.5 54.5
ini szz add _szz1 range z 0 51.5
end_command
_grad=-2080*(-9.81)
_szz1=-_grad*(51.5-43.5)
_szz0=-_grad*43.5
command
ini szz add _szz0 grad 0 0 _grad range z 51.5 43.5
ini szz add _szz1 range z 0 43.5
end_command
_grad=-1980*(-9.81)
_szz1=-_grad*(43.5-37.5)
_szz0=-_grad*37.5
command
ini szz add _szz0 grad 0 0 _grad range z 37.5 43.5
ini szz add _szz1 range z 0 37.5
end_command
_grad=-1920*(-9.81)
_szz1=-_grad*(37.5-31.5)
_szz0=-_grad*31.5
command
ini szz add _szz0 grad 0 0 _grad range z 31.5 37.5
ini szz add _szz1 range z 0 31.5
end_command
_grad=-1880*(-9.81)
_szz1=-_grad*(31.5-21.5)
_szz0=-_grad*21.5
command
ini szz add _szz0 grad 0 0 _grad range z 21.5 31.5
ini szz add _szz1 range z 0 21.5
end_command
_grad=-1900*(-9.81)
_szz0=-_grad*21.5
command
ini szz add _szz0 grad 0 0 _grad range z 0 21.5
end_command
end
def ini_conf
pnt=zone_head
loop while pnt # null
val=0.43*z_szz(pnt)
z_sxx(pnt)=val
z_syy(pnt)=val
pnt=z_next(pnt)
end_loop
end
ini_conf
model mohr range group pile
prop bulk 2.0e10 shear 1.0e10 fric 30 cohesion 3.0e6 ten 2e6 density 2300 range group pile id=1
prop bulk 2.5e10 shear 1.15e10 fric 50 cohesion 3.8e6 ten 4e6 density 2500 range group pile id=2
prop bulk 2.0e10 shear 1.0e10 fric 30 cohesion 3.0e6 ten 2e6 density 2300 range group pile id=3
;=============创建梁单元===============
sel beam id=1 begin 30 0 55.8 end 30 2 55.8 nseg=2
sel beam prop emod=30e9 nu=0.2 density=2.5e3 ran sel beam
;=============边界条件=================
fix z range z -0.1 0.1
fix x range x -0.1 0.1
fix x range x 99.9 100.1
fix y range y -0.1 0.1
fix y range y 1.9 2.1
;===============应力条件================
apply szz -20e3 ran z 59.9 60.1
ini szz 0e3
ini sxx 0e3
ini syy 0e3
set grav 0 0 -9.81
hist unbal
solve
save 自重平衡.sav
显示：Zero stiffness in grid-point 17 命令流出错了。
我实在是找不出原因，大概是赋值的问题，但是具体错在哪儿了，不知道，请求大神帮忙！！！
给我指点指点，帮忙把这个问题解决了，非常感谢啊！！！！！！！！！！！！！！！！
