求安全系数，就是稳定系数（fos），的具体命令是什么啊？
我输入solve fos 后总是算不出来。
附程序命令：
gen zone brick &
p0 0 0 0 p1 2 0 0 p2 0 0.5 0 p3 0 0 2 &
size 3 1 3
gen zone brick &
p0 2 0 0 p1 13.4 0 0 p2 2 0.5 0 p3 2 0 2 &
size 8 1 3
gen zone brick &
p0 13.4 0 0 p1 20 0 0 p2 13.4 0.5 0 p3 13.4 0 2 &
size 6 1 3
gen zone brick &
p0 2 0 2 p1 13.4 0 2 p2 2 0.5 2 p3 12 0 12 &
p4 13.4 0.5 2 p5 12 0.5 12 p6 16 0 12 p7 16 0.5 12 &
size 8 1 17
gen zone brick &
p0 13.4 0 2 p1 20 0 2 p2 13.4 0.5 2 p3 16 0 12 &
p4 20 0.5 2 p5 16 0.5 12 p6 20 0 12 p7 20 0.5 12 &
size 6 1 17
model mohr
prop den=2000.0 bulk=1.0E8 shear=3.0E7 coh 12380.0 tens 1.0E10 &
friction=20 dilation=20
fix x y z range z -0.1 0.1
fix x range x 19.9 20.1
fix x range x -0.1 0.1
fix y
set gravity = 10.0
solve fos file slope3dfos.sav associated
ret
