20614 Capacity Design Principle

The main objective of the capacity design principle is to ensure the desirable mechanisms can dissipate significant amounts of energy and inelastic deformation (plastic hinging) occurs at expected locations (at top and bottom of columns) where they can be readily inspected and repaired. To achieve this objective, the overstrength force effects developed from the plastic hinges in columns shall be dependably resisted by column shear and adjoining elements such as cap beams, spread footing, pile cap, and foundations. The moment overstrength capacity (Mpo) can be assessed using one of the following approaches:

1.5Mn for concrete column

1.2Mn for steel column, Mn based on expected yield strength 1.3Mn for concrete filled steel tubes

1.5Mn for steel piles in weak axis bending and for steel members in shear (e.g., eccentrically braced frames) 1.0Mn for geotechnical design force in SDR3

For reinforce concrete columns [46]

Mp0 = Mbo where

0 0

Post a comment