| Applies To | |||
| Product(s): | AutoPIPE, | ||
| Version(s): | ALL | ||
| Environment: | N/A | ||
| Area: | Load | ||
| Original Author: | Bentley Technical Support Group | ||
Problem:
How to determine ground elevation in AutoPIPE?
Solution:
AutoPIPE allows the user to create a piping system anywhere within the coordinate system constraints, BUT, how does the program know where the Ground level is unless you tell it!
Ground level could be anywhere on the vertical axis: ex. -4000 mm, -125 ft, 0 ft, +30 ft, +86645mm, anywhere, etc….
Just identify vertical level where ground level exists, and anything below that vertical level is considered underground. Anything underground will have no wind applied.
Notes:
- When specifying wind load profile elevation values, remember to check that ground is correctly defined on the main Wind dialog screen. This applies also to wind loadings per ASCE-7 and UBC.
- Opening older AutoPIPE models may display a warning message "negative elevations found" may indicate an incorrect wind loading across this model.
- If the Wind Ground elevation value was found to be greater than all the vertical pipe coordinates in a model, than the entire model would be considered to be underground and thus no Wind load will be applied. Confirm Wind load ground elevation relative to the piping model.
Example:
Given the following piping system, What value should be entered for "Ground elevation" on the Wind dialog?
Do you agree that 10 feet is correct answer? Yes or No...
If you had answered YES, you are WRONG.
If you had answered "No, need more information", you are CORRECT.
The missing information, what is the Vertical elevation of the elbow at the top of the vertical pipe?
From the Point tab of the input grids, vertical axis = Y-axis, one can see that the Vertical coordinate at the elbow A210 = -225.460
Therefore the Ground elevation = -225.460 - 10 = -235.460 ft.
Correct !!!
Again, baring any Wind Segment settings, any piping above this elevation could have wind applied, but all piping below this elevation would not have any wind applied regardless of Wind / Segment settings.