;第1步
rest Gsol.sav
initial xdisplacement = 0 ydisplacement = 0 zdisplacement = 0
initial xvelocity = 0 yvelocity = 0 zvelocity = 0
initial state = 0
;定义开挖面支护压力参数
def sup_stress
lumda=0.9
o_press=-73125
o_grad=0.75e4
s_press=o_press*lumda
s_grad=o_grad*lumda
end
sup_stress
;开挖第一环
def excate_step1
n=1
a1=1.2*n-1.2
a2=1.2*n
b1=1.2*n-0.01
b2=1.2*n+0.01
n1=16*n-1
n2=16*n
end
excate_step1
;开挖第一环地层单元并设置管片支护
model null range cyl end1 -9.75 a1 0 end2 -9.75 a2 0 rad 3.25
;管片壁后注浆体
model elas range group slurrz y a1 a2
ini density 2000 range group slurrz y a1 a2
prop young 1e6 poisson 0.3 range group slurrz y a1 a2
;添加管片支护
sel shell id=1 range cyl end1 -9.75 a1 0 end2 -9.75 a2 0 rad 3.11 group inrz not
sel node local xdir 1 0 0 ydir 0 -1 0 range x -0.1 0.1
sel node fix lsys range x -0.1 0.1
sel node fix x yr zr range x -0.1 0.1
sel node local xdir 0 0 -1 ydir 0 -1 0 range y -0.1 0.1
sel node fix lsys range y -0.1 0.1
sel node fix y xr zr range y -0.1 0.1
sel shell id=1 prop iso=(3.45e10,0.3) thick=0.35 density 2450
sel shell apply press -350e3 range cid n1 n2
apply nstress s_press grad 0 0 s_grad range cyl end1 -9.75 b1 0 end2 -9.75 b2 0 rad 3.25
set mech ratio 1e-5
solve
save step1.sav
call step2.txt

楼主，请问这句sel shell apply press -350e3 range cid n1 n2中-350e3的大小和n1、n2的范围是怎么确定的，期待你的回复