support reactions are not symmetrical

[saclovitzky]

Hello,

I've modelled a retaining wall with point supports with equal distance,I expect that the result is symmetrical(,ie, half of the joint supports shld be equal to the other half of joint supports) but the result is different.

any reason for this?any help will be greatly appreciated(pls. see attached file)

[Simau · Accepted solution]

@saclovitzky 

You have type 2 instability, use fixed supports instead.

The accurancy depend of the mesh size