Design & Analysis of Stairs Using SAP2000

• WD =50 lb/ft² , WL= 75 lb/ft²

• Slab waist = 6”, f’c= 4ksi; fy = 60 ksi

Steps:

• Unit = lb-ft

• Model= stair cases
  • Stair type = type2,
  • Right level width= 6”,
  • Storey height = 13”,
  • Stair projected length = 11.25’
  • Opening b/w stairs = 1,
  • width1=5’,
  • width2 =6’
  • Max mash spacing = 1

• Option>preference> concrete frame design ACI-2003

• Define> material concrete, modify, f’c =4 ksi, fy=60ksi

• Define > area section, modify, name= slab6. Thickness= 6”

• Define > load cases, line load

• Define > add default combo

• Select waist slab

• Select > invert selection

• Assign > area > local axis, -90°

• Select All

• Assign > Area load > uniform assign loads

• Analysis > analysis option, 3D

• Analysis > run analysis; model “Do NOT RUN” Run Now

• Display > show forces > area M11, M22

• Display > show forces > area AST1, AST2