AaronMcD
Structural
- Aug 20, 2010
- 273
The setting is a voluntary seismic retrofit of 4 story wood house built in 1919. "Voluntary" being the key word here.
There are currently tenants on each floor except the bottom floor, so we may only get to strengthen the lowest level. But that doesn't help all THAT much due to diaphragm irregularities and weakness. The diaphragms are "H" shaped because of a stairwell in front and a light & stair well in back.
I am using ASCE 41-13 as a general guideline. The load levels are expected loads. Diaphragm expected capacity is what I'm looking for. We are also offering a full solution with enough chords and collectors and interior shear walls and transfer beams, etc. I also want to offer a mid-level solution designed for approximately half the expected forces. But the diaphragm needs some tension capacity for a mid-level solution to work, therefore the question. I could add chords until I get under some tension level in the sheathing, but having some rationale would be nice.
There are currently tenants on each floor except the bottom floor, so we may only get to strengthen the lowest level. But that doesn't help all THAT much due to diaphragm irregularities and weakness. The diaphragms are "H" shaped because of a stairwell in front and a light & stair well in back.
I am using ASCE 41-13 as a general guideline. The load levels are expected loads. Diaphragm expected capacity is what I'm looking for. We are also offering a full solution with enough chords and collectors and interior shear walls and transfer beams, etc. I also want to offer a mid-level solution designed for approximately half the expected forces. But the diaphragm needs some tension capacity for a mid-level solution to work, therefore the question. I could add chords until I get under some tension level in the sheathing, but having some rationale would be nice.
