边坡不加桩安全系数为1.63，加了桩安全系数竟然降到了1.01，求解答！！
.命令流如下：
n
;===================================
;建立网格模型
gen zone brick &
p0 0 0 -10 p1 2 0 -10 p2 0 0.5 -10 p3 0 0 3 size 3 1 13
gen zone brick &
p0 2 0 -10 p1 20 0 -10 p2 2 0.5 -10 p3 2 0 3 &
size 17 1 13 ratio 1.03 1 1
gen zone brick &
p0 2 0 3 p1 20 0 3 p2 2 0.5 3 p3 12 0 13 &
p4 20 0.5 3 p5 12 0.5 13 p6 20 0 13 &
p7 20 0.5 13 size 17 1 17 ratio 1.03 1 1
;====================================
;设置边界条件
fix x y z range z -10.1 -9.9
fix x range x 19.9 20.1
fix x range x -0.1 0.1
fix y
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;初始地应力的生成
model elas
prop density 2000 bulk 3e9 shear 1e9
set gravity 0 0 -10.0
solve
ini xdisp 0 ydisp 0 zdisp 0
ini xvel 0 yvel 0 zvel 0
;===================================
;安全系数求解
model mohr
prop shea 0.852e7 bulk 2.55e7 dens=2000 fric=20 dila 20 cohes=3e4
sel pile id=1 beg 10 0.25 11 end 10 0.25 3 nseg 8
sel pile id=1 prop emod=3.17e10 nu=0.2 xcar=4.5 xciz=1.63 xciy=1.63 &
xcj=3.26 dens=2500 perim=2.5 cs_scoh=75.4e3 cs_sfric=20.0 cs_sk=3.686e8 cs_ncoh=75.4e3 &
cs_nfric=20 cs_ngap=off cs_nk=3.686e8 slide=on ;;;;;桩的参数
solve fos file slope3dfos1.sav associated
