Liner simulation in excavating process

When I simulating the liner as retaining wall during excavating process, the system can not get equillibrium.
In 2D, the liner is a beam-type element, and share some properties with beam. So I create the liner with by-line command, but in my model, the links between the liner and zones are seems failed to create.

model new
model large-strain off
zone ratio convergence
struct ratio convergence
model gravity 10

zone create quad p 1 20,0 p 2 0 20 size 20 40
zone group 'ex1' range p-x 0 5 p-y 20 18
zone group 'ex2' range p-x 0 5 p-y 18 16
zone group 'ex3' range p-x 0 5 p-y 16 15

zone face skin
zone cm ass m-c
zone prop density 2000 young 10e6 poisson 0.3 fric 20 cohesion 10e3
zone gp fix vel range group 'bottom'
zone gp fix vel-x range group 'east' or 'west'

model solve elastic
zone gp ini disp 0 0
zone gp ini vel 0 0

struct liner create by-line 5,20 5,10 seg 10

struct liner cmodel assign elastic
struct liner property young 200e9 poisson 0.25 density 2000 cross-sectional-area 0.2 moi 1.3e-4

struct liner property coupling-stiffness-normal=1e11 coupling-stiffness-shear=1e11 coupling-friction-shear=10.0
struct liner property coupling-stiffness-normal-2=1e11 coupling-stiffness-shear-2=1e11 coupling-friction-shear-2=10.0

model solve

the stress field in zones is unchanged.
Would anyone help me to check it?

You should create the liner as follows

struct liner create by-zone-face embedded separate range group pos-x 5 tol 0.01 pos-y 10 20

It does works! Thanks for your reply!