escads dois lances, Notas de estudo de Cultura

Baixe escads dois lances e outras Notas de estudo em PDF para Cultura, somente na Docsity! DESIGN OF DOG-LEGGED STAIR Name of work :- pkn 1 Stair hall measure 2.50 x 5.00 m 2 Available verical space between floor 3.00 m 3000 mm 3 Horizontal Span of stair case 1.20 mtr 1200 mm 4 Risers 0.15 mtr 150 mm 5 Treads 0.25 mtr 250 mm 6 Conrete M - 20 wt. of concrete 25000 7 m 13.33 7 Steel fy 415 230 8 Nominal cover 25 Effective cover 30 mm Reinforcement Main Bottom slab 10 100 mm c/c Anchor bars (Bottom ) 8 2 Nos. Strirrups 8 270 mm c/c 10 200 mm c/c 2050 1750 1200 150 1.20 250 1200 10 100 mm c/c 3.00 150 8 270 mm c/c 250 1.80 10 200 mm c/c 180 mm 1050 1050 2.75 1200 N/m3 s cbc N/mm2 s st N/mm2 mm F bars mm F bars mm F bars mm f mm f mm f mm f pk_nandwana@yahoo.co.in DESIGN OF DOG-LEGGED STAIR Name of work :- pkn Stair hall measure 2.50 x 5.00 Available verical space between floor 3.00 m Horizontal Span of stair case 1.20 m 1200 mm Risers 0.15 m 150 mm Treads 0.25 m 250 mm Concrete M- 20 wt. of concrete 25000 7 m 13.33 Steel fy- 415 230 Nominal cover 25 mm Effective cover 30 mm 1 Genral arrngment:- Fig. shows plan of stair hall. = 3.00 / 2 = 1.50 m minimum 1.8 m which is heigher No. of risers required = 1.80 / 0.15 = 12 No. of treads required = 12 - 1 = 11 No. in 1st flight. Spce occupied by treads = 11 x 0.25 = 2.75 m Keep width of landing equal to = 1.20 m = 1.05 m = 1.20 m No. of risers required = 1.20 / 0.15 = 8 No. of treads required = 8 - 1 = 7 No. in 2nd flight. Spce occupied by treads = 7 x 0.25 = 1.75 m Keep width of top landing = m 2 Design Constants:- For HYSD Bars Cocrete M = 20 = 230 wt. of concrete = 25000 = 7 m = 13.33 m*c = 13.33 x 7 = 0.289 13.33 x 7 + 230 = 1 - 0.289 / 3 = 0.904 = 0.5 x 7 x 0.904 x 0.289 = 0.913 3 Loading Each Flight :- The landing slab is assume to span in the same direction as stair, and is considered as acting together to form a single slab. Let the bearing of landing slab in wall be = 160 mm The effective span = 2.75 + 1.20 +( 0.16 / 2 )'= 4.03 m say = 4.00 m Let the thickness of waist slab '= 5.00 x 40 = 200 mm = 0.2 x 1 x 1 x 25000 = 5000 x = 5000 x 150 250 5831 T 250 = 1 x 150 x ### = 1875 N/m 2 1000 = 7706 N Weight of fiishing etc. = 100 N Live load = 2500 N Total weight = 10306 N Note. The load w on the landing portion will be 10306 - 1875 = 8431N, since weight of step will not come on it. However, a uniform value of w has been adopted here. N/mm2 s cbc N/mm2 sst N/mm2 Height of 1st flight. No. in 1st flight. \ Space left for passage Height of 1st flight. No. in 2nd flight. sst N/mm2 N/mm2 scbc N/mm3 k = m*c+sst j =1-k/3 R =1/2xc x j x k \Weight of slab w' on slope N/m2 Dead weight of horizontal area w 1 = w' R 2+T2 2+ 2= N/m2 Dead weight of step is w2 \ Total Dead weight per meter run DESIGN OF DOG-LEGGED STAIR which is heigher The landing slab is assume to span in the same direction as stair, and is considered N, since weight of step will not come on it. However, mm mm2 mm2 DESIGN OF DOG-LEGGED STAIR 2.50 1.20 2.75 UP 5.00 1.05 1.20 11 10 9 8 270 8 7 ### ### 6 250 5 150 4 3 2 1 Foor level 1.20 2.75 1.05 mm F c/c mm F c/c