# Liner simulation in excavating process

**URL:** <https://forum.itascainternational.com/t/liner-simulation-in-excavating-process/1147>\
**Category:** FLAC2D\
**Created:** [August 27, 2023, 7:07am UTC](https://forum.itascainternational.com/t/liner-simulation-in-excavating-process/1147 "2023-08-27T07:07:14Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Sullivan](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Sullivan](https://forum.itascainternational.com/u/Sullivan)\
**Post date:** [August 27, 2023, 7:07am UTC](https://forum.itascainternational.com/t/liner-simulation-in-excavating-process/1147/1 "2023-08-27T07:07:14Z")

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Hi,  
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.

```auto
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?

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<div class="post-metadata">

**Author:** ![Huy](https://avatars.discourse-cdn.com/v4/letter/h/c5a1d2/32.png) [@Huy](https://forum.itascainternational.com/u/Huy)\
**Post date:** [August 28, 2023, 6:20am UTC](https://forum.itascainternational.com/t/liner-simulation-in-excavating-process/1147/2 "2023-08-28T06:20:10Z")

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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

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<div class="post-metadata">

**Author:** ![Sullivan](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Sullivan](https://forum.itascainternational.com/u/Sullivan)\
**Post date:** [August 28, 2023, 10:51am UTC](https://forum.itascainternational.com/t/liner-simulation-in-excavating-process/1147/3 "2023-08-28T10:51:27Z")

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It does works! Thanks for your reply!