求助一个关于施加动荷载的问题，求高手

phistc

  最近在做一个有关地震台的UDEC模型，要求把一个块体放在一个不停震动的台子上面，但是我把动荷载施加了之后只能让上面的块体产生一个上下的震动，我想的却是让下部分的台子产生一个左右不停的震动，让上部分的块体发生坍塌。我想的是下部分的台子再Y方向是固定的，只有左右震动，但是我试过了之后发现固定了Y方向之后整个模型不发生变化，不知道我的施加方法出了问题还是什么，下面是我输入的程序：
config cell 10 10
round 0.018000001
edge 0.036000002
block -6.0,-6.0 -6.0,12.0 12.0,12.0 12.0,-6.0
crack -6.0,0.0 12.0,0.0
crack -4.0,0.0 -4.0,10.0
crack -4.0,10.0 10.0,10.0
crack 10.0,10.0 10.0,0.0
crack 10.0,12.0 10.0,10.0
crack -4.0,12.0 -4.0,10.0
delete range atblock -5.0,6.0
delete range atblock 3.0,11.0
delete range atblock 11.0,6.0
crack -12.0,-5.0 12.0,-5.0
delete range atblock 3.0,-5.5
crack -4.0,2.0 10.0,2.0
crack -4.0,4.0 10.0,4.0
crack -4.0,6.0 10.0,6.0
crack -4.0,8.0 10.0,8.0
crack -2.0,0.0 -2.0,10.0
crack 0.0,0.0 0.0,10.0
crack 2.0,0.0 2.0,10.0
crack 4.0,0.0 4.0,10.0
crack 6.0,0.0 6.0,10.0
crack 8.0,0.0 8.0,10.0
gen edge 0.5
group zone 'rock:donghezai'
zone model elastic density 1000.0 bulk 9.4444442E8 shear 7.0833331E8 range group 'rock:donghezai'
joint model area jks 9.9999998E10 jkn 9.9999998E10 nstable 0 jfriction 5.0 jcohesion 10000.0 jtension 0.0 jdilation 0 zdilation 0 jperm 0 ares 0 azero 0 empb 0 expa 0 range -4.738732,10.669014 -1.2415493,10.238731
boundary xfree yfree range -7.0859146,13.085915 -4.7274647,10.587323
boundary stress 0,500,0 hist=cos(100.0,1000 )range 11.993662,13.062675 -5.33169,0.26901412
set gravity=0.0 -9.8
history unbal
history xdis 3.0,10.0
history ydis 3.0,10.0
joint model area jks 9.9999998E10 jkn 9.9999998E10 nstable 0 jfriction 5.0 jcohesion 10000.0 jtension 0.0 jdilation 0 zdilation 0 jperm 0 ares 0 azero 0 empb 1.0 expa 3.0 range -4.2971826,10.04155 -0.42816877,10.517605
boundary yvelocity 0.0 range -6.365493,12.1098585 -5.33169,-4.9366193
我试过把最后的动荷载改为X方向或者是XY的剪力方向 但是结果都是一样，不知道问题在哪 现在很急，求一个高手解答 我的QQ是409719868，要是有高手愿意介绍点经验非常感谢

指数先生

你施加的力为啥是sxy的？