Stair DesignStair Types Stair TypesStraight stairsStair Type based on the structural loading typeSimply supported stair (transversely supported)Longitudinally supported stair( y pp )Cantilever stairSimply supported stair Simply supported stairDesign a straight flight stair in a residential building supported on i f d t ll 1 5 )( t t t ) reinforced concrete wall 1.5 m )(center to center)L.L = 3kN/m2Covering Material = 0.5kN/mThe riser are 16cm and goings are 30 cmLoadsandAnalysis Loads and Analysiscmlh 5 . 72015020min= = =cm have5 . 165 . 78cos5 . 7820 202 216 3016= + = + =+oo16 30 +D.L( D.L(O.W O.W) = ) =0 0..34 34* *00..075 075* *2525 ++ 0 0..5 5* *00..16 16* *00..3 3* *25 25= =1 1..2424 kN/m kN/mD.L (covering material) =D.L (covering material) = 0 0..55 kN/m kN/m0.30.160 34D.L (total) =D.L (total) = 1 1..7474 kN/mkN/m L.L = L.L =33*( *(0 0. .33) = ) =0 0. .99 kN/m kN/m0.34Designfor moment Design for moment139 9 . 13 6 . 0 2 5 . 16. 1mm cm dm kN Mu= = = =( )9 . 0300 306lim| assumemm cm bw( | | = s = =( )( ) ( )9 0 1 89 165 * 300 * 0018 00005 . 0139 00 3 25 9 . 0 85 . 01 10 21 142025 85 . 02 2min26 cm mm As = = =< =(((

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\| =step eachfor12 19 . 0 1 . 89 165 300 0018 . 0min|usecm mm As = = =25Design for shearu CV kN V > = = 26 1000 / 300 13962575 . 0 |Longitudinal Supported stairs LongitudinalSupported stairsLongitudinal Supported stairs (Example)Design a U- stair in a residential building L.L = 3 kN/m2Covering Material = 2 kN/m2g d pp d ( p )Covering Material = 2 kN/m2The riser are 16 cm and goings are 30 cmLoadsandAnalysis Loads and Analysiscmlh 2252585 0i~ = = cm h 2220 2085 . 0min~D.L ( D.L (slab slab)) == 0 0..22 22* *2525 = =5 5kN/m kN/m22 D.L (step) =D.L (step) = 0 0..5 5* *00..16 16* *25 25= =22 kN/m kN/m22D.L (covering material) =D.L (covering material) = 22 kN/m kN/m22// D.L (flight) =D.L (flight) = 99 kN/m kN/m22 D.L (landing) =D.L (landing) = 77 kN/m kN/m2 2L.L = L.L =33 kN/m kN/m22WWuu (flight) =(flight) = 1 1..22( (99)+ )+1 1..66( (33)= )=15 15. .66kN/m kN/mWWuu(landing) =(landing) = 11. .22( (7 7)+ )+1 1..66( (33)= )=13 13. .22kN/m kN/mDesignfor moment Design for moment194 4 . 19 6 . 0 2 22. 2 . 52mm cm dm kN Mu= = = =( )9 . 01050 1056lim| assumemm cm bw( | | = s = =( )( ) ( )33 7 32 733 194 * 1050 * 0036 00036 . 0194 050 1 25 9 . 0 85 . 02 . 52 10 21 142025 85 . 02 226cm mm As = = ==(((

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\| =12 833 . 7 32 . 733 194 1050 0036 . 0min|usecm mm As = = =25Design for shearu CV kN V > = = 3 . 127 1000 / 1050 19462575 . 0 |Reinforcement Notes Reinforcement NotesCantilever Stair Cantilever StairCantilever stairs (Example) ( p )Design a cantilever straight flight stair in a residential buildingL L 3kN/ 2 L.L = 3kN/m2Covering Material = 0.5kN/mThe riser are 16cm and goings are 30 cmcmlh 151015010min= = =D.L( D.L(O.W O.W) = ) =00..15 15**00..075 075**25 25 ++ 00..15 15**00..075 075**25 25==00..66 kN/m kN/m D.L( D.L(O.W O.W))00..15 15 00..075 075 2525 00..15 15 00..075 075 25 25 00..66 kN/m kN/mD.L (covering material) =D.L (covering material) = 0 0..55 kN/m kN/mD.L (total) =D.L (total) = 11..11 kN/mkN/m( ) ( )L.L = L.L =33*( *(0 0. .33) = ) =0 0. .99 kN/m kN/mWu =Wu = 1 1..22( (11..11)+ )+1 1..66( (00. .99) =) = 2 2. .7676 kN/m kN/m 15Vu =Vu = 22..76 76((11..55) =) = 44..1414 kN kNMu = W Mu = WuuLL22//22 == 3 3. .11 kN.m kN.m 157.5Designfor moment Design for moment194 4 . 12 6 . 0 2 15. 1 . 3mm cm dm kN Mu= = = =( )9 . 075 5 . 76lim| assumemm cm bw( | | = s = =( )( ) ( )72 0 61 71 124 * 75 * 0077 00077 . 0124 5 7 25 9 . 0 85 . 01 . 3 10 21 142025 85 . 02 226cm mm As = = ==(((

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\| =10 272 . 0 61 . 71 124 75 0077 . 0min|usecm mm As = = =25Design for shearu CV kN V > = = 8 . 5 1000 / 75 12462575 . 0 |Longitudinal Supported stairswell stairs - OpenGeneral Example