Salam
I am designing a 2 storey building columns are 12 " x 15", building is in seismic zone 3 so detailing require SMRF. for ties spacing according to ACI-308-08 section 21.5.3.2 the option a governs with d/4. my question is tie spacing becomes 2.625 inches as i consider d=12-1.5=10.5 for 12" s...