Column Design --> e-min effect consideration in the calculation.

Document Information

Document Type: FAQ

Product(s): LEAP RCPIER/Substructure

Version(s): All

Original Author: Bentley Technical Support Group -VM

QUESTION:  How the program is considering the e-min effect in the column design ?


For Mz calculation shown in the Column Design status we compare the Mz value in the Analysis tab with the moment generated due to the minimum eccentricity and use the maximum value in the Column Design.  RC-PIER will multiply the minimum eccentricity (0.6 + 0.03h) with the axial force to obtain the moment. 

For example: I have a model with three columns with drilled shaft and the Mz in the column design status is showing as -111.7 k-ft.  The analysis for Load combination shows -85.83 k-ft.

Eccentricity  = 0.6 + 0.03 h   {h = 60”}

                          = 0.6 + 0.03*60’

                           = 2.4”

                           = 0.20’

Fy  = 558.7 kips

Mz = Fy * eccentricity

        = 558.7 * 0.20

        = 111.74 k-ft