Lpile Plus 5.0 and seismic loadings.

[DakotaEngineer]

I am trying to model a 36-inch diameter concrete pier where the structural engineer has provided the live and dead axial loads, seismic lateral and seismic moment loads to provide alowable lateral loads for fixed head and free head conditions. I am not sure how to incorporate the seismic loads. According to the manual, to model a free head condition, you use boundry condition 1, provide the lateral force and set the monemt to zero. For a fixed head you use boundry condition 2 and provide the lateral load and set the slope to zero. Neither case accounts for the seismic moment and my guess is that the lateral load would be the combination of the allowable lateral load plus the seismic lateral load. I am trying to limit the deflection to 1/4". Any ideas or help would be appreciated. Thanks

 

[jdonville]

I would call the structural to verify that the seismic moment is the design moment for the extreme event condition - including contributions by dead, wind, live (etc.) loads, or not.

J

 

[ishvaaag]

In any case if you have a significant moment it is likely you wouldn't be using a single pile, likely a group in a pilecap ... resolved to axial forces ... this won't eliminate your worries but maybe diminish them.

On the other hand the structure maybe a small one and maybe pile groups may be seen excessive. You can resource then to a 3D model in some general analysis program, yet then woun't get straight out of the box the conveniences of a program like Lpile.