Foundation uplift
- Ondrej
- Mike Abell (Unlicensed)
On this page:
How do I model bearings with uplift?
Answer: Bearings with uplift may be modeled using nonlinear gap (compression-only) link objects. In that these objects demonstrate nonlinear behavior, nonlinear analysis must be specified in the load case. Additional details are available in the CSI Analysis Reference Manual (The Link/Support Element - Advanced > Gap Property, page 258) and in Verification Example 6-003, available through Help > Documentation > Analysis Verification > Links.
How do I model a tension pile when uplift forces exceed dead load?
Answer: To model a pile for the case in which it resists only tension, and not compression, two options are available, described as follows:
- Frame object – Model a frame object with a zero compression limit.
- Link object – Model a link object using the nonlinear hook property.
NOTE: A nonlinear load case must be applied to activate the nonlinear properties of these structural objects, and to characterize uplift behavior.
How do I know if uplift occurs?
Answer: Review the bearing pressure for various uplift cases to determine whether or not uplift occurs. Regions with zero bearing pressure will indicate uplift.