我仅考虑了自重应力场，可是居然出现了正值，不知道该怎么解决

这是建模的代码
new
config dyn
set dyn off
gen zone brick p0 0 0 0 p1 70 0 0 p2 0 30 0 p3 0 0 30 p4 70 30 0 p5 0 60 30 p6 10 0 30 p7 10 60 30 size 8 12 12
gen zone reflect dd 0 dip 90
gen zone uwedge p0 70 0 -30 p1 70 30 0 p2 0 0 -30 p3 70 -30 0 size 12 8 12
gen zone uwedge p0 130 0 -30 p1 130 30 0 p2 70 0 -30 p3 130 -30 0 size 12 6 12
gen zone reflect dd 90 dip 90
attach face
fix x y z
ini xv 0 yv 0 zv 0 xdisp 0 ydisp 0 zdisp 0
free x y z
range name dam z =0.1 30
range name foundation z=-30 0
group zone dam range nrange dam
group zone foundation range nrange foundation
model mech mohr range=nrange dam
prop shea 1e8 bulk 2e8 cohes 1e10 range=nrange dam
prop tens 1e10 range=nrange dam
ini dens 1700 range=nrange dam
model mech elas range=nrange foundation
prop shea 5e8 bulk 1e9 range=nrange foundation
ini dens 2100 range=nrange foundation
save dam0
return
这是施加边界条件的代码
restore dam0
range name left plane dd 0 dip -45 orig 0 60 30 dist 0.5
range name right plane dd 0 dip 45 orig 0 -60 30 dist 0.5
range name valley union nrange left nrange right
range name east_end plane dd 90 dip 90 orig 130 0 0 dist 0.5
range name west_end plane dd 90 dip 90 orig -130 0 0 dist 0.5
range name ends union nrange east_end nrange west_end
range name bottom_line z=-35.0 -29.5
apply nvel=0.0 plane dd 0 dip -45 range nrange left nrange bottom_line not
apply nvel=0.0 plane dd 0 dip 45 range nrange right nrange bottom_line not
apply xvel=0.0 range nrange ends nrange bottom_line not nrange valley not
fix y z range nrange bottom_line
set grav 0 0 -10 small
his add unbal
solve
save dam1
return
按理说是不会出现正值应力的，这种问题请问应该怎么解决？

应该是边界条件设置出了问题，但是我改不出来，有没有大神教教我?

你好，解决了吗