How to model lateral soil springs for long pile in SAP2000

[T9X]

Hi all,

I am making a sap2000 model to demonstrate the lateral load acting on a long bored pile which resisted by lateral soil spring.
There is different soil layer that I make use of "2 joint LINK" to represent different spring stiffness at certain depth.

However, the BMD output is very weird that when I increase the stiffness of springs, the BM also increase.
When I decrease the stiffness of springs (say close to zero), the BM will be very small.

I think there is something wrong with my program setting, anyone can help? Thanks!!!!!

My link setting:
2 joint Link
fixed support at one joint
Link property = linear
directional: U1 only

 

[T9X]

push, iam urgent....

 

[stressed]

Check local axes of your link. A linear link is spring stiffness K with option to include damping C. You might try modeling with 1 point link using the correct local axis and see if using a 1 point link solves the problem.

Multi-linear plastic spring can account for nonlinear soil PY TZ data.