DESIGN REQUIREMENTS FOR SEISMIC DESIGN CATEGORY A

[nour75]

Item 11.7.3 in ASCE7-05 says “Any smaller portion of the structure shall be tied to the remainder of the structure with elements having design strength of not less than 5 percent of the portion's weight.”

What is the relation between the 5% portion's weight and the element design strength?. Can any one give example for this?

 

[JAE]

This is similar to 12.1.3 and I believe it is only speaking of the connection-design between individual structural members that tie "smaller portions" of a building to larger portions. This would be when you'd have a smaller 1 story section of building tied into a larger 3 story portion, perhaps.

 

[Teguci]

Other than the element having to have enough strength to transfer 5% of its weight to a lateral bracing system, there is no relationship.

Its not until Seismic Design Categorys C, and up that you start having to deal directly with plastic hinging and energy absorption.

And, where you start looking at element strength and eliminating failure locations.