REINFORCED CONCRETE BUILDING DESIGN. Beam design M.S.KIRÇIL

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1 REIFORCED COCRETE BUILDIG DESIG Beam design.s.kirçil

2 Reinforced Concrete Lecture otes A continuous beam with a width of m is analzed under the effect of load combination's; so that, the maimum value of span and support moments can be determined. P d g P d g ma ma 3 g P d g P d ma ma 4 P d P d g P d X X ma ma ma 3 ma 4 Design moments

3 Reinforced Concrete Lecture otes A continuous beam with a width of m is analzed under the effect of load combination's; so that, the maimum value of span and support moments can be determined. g P d P d g X P d g P d P d X 3 For detailed information on load combinatins see: YAPI STAT, brahim Ekiz, 005 X X X 3 ma ma ma 3 ma 4 Design moments

4 400 K04 K05 K K04 K05 K06

5 P d K04 K05 K06 P d ma. moment at each section from.4g+.6q loading groups P ma. moment at each section from G+Q loading groups P E K04 K05 K06 ± K04 K05 K06 0.9G E K04 K05 K06 ± K04 K05 K06

6 oment düzeltmesi Kesme kuvveti düzeltmesi Etrie hesabı

8 Reinforced Concrete Lecture otes Dr. Rectangular beam design (single reinforced or double reinforced) T or rectangular beam design

12 FOUDATIOS Safet for both foundation and soil must be provided with the proper foundation design. The load must be limited with the ultimate capacit of soil. The sufficient material, dimension and reinforcement must be provided for foundation so that loads can be transmitted to soil safel.

13 Safet for soil FOUDATIOS a) The soil pressure must be limited with the allowable stress of the soil under the effect of serviceabilit loads. (G + Q ) z z,safe b) The soil pressure must be limited with the times of allowable stress of the soil under the effect of vertical and earthquake loads. (G + Q E) z z,safe Soil tpe A.5 B.5 C.5 D.0

14 FOUDATIOS Safet for foundation.4g+.6q G+Q E 0.9G E The design load is the ma. of the considered load combinations. Load combination Loads of structure Internal force of foundation -.4G +.6Q p, p, H p, V, V p - G + Q E p, p, H p, V, V p 3-0.9G E p3, p3, H p3 3, V 3, V p3 p p p H p p H p V

15 FOUDATIOS Safet for foundation Load combination Internal force of foundation -.4G +.6Q, V, V p - G + Q E, V, V p 3-0.9G E 3, V 3, V p3 d ma 3 V d ma V V V3 V p <V pr V p <V pr V p3 <V pr3 Safet for bending Safet for shear: The shear strength provided b concrete section OLY must be sufficient V d < V cr Safet for punching

16 DETERIATIO OF DIESIOS h d d d -Ø The higher moment requires the higher effective depth. Therefore, the reinforcement determined with the higher moment is placed at the bottom of footing. The effective depth for the higher moment d h 5cm The effective depth for the lower moment d d -Ø Ø can be assumed 6mm

17 G h d V pd V pr ( a + d mean )( a + d bb mean ) γf ctd U p d mean U p ( a + a + dmean ) Assume that without considering bending moment Solve the second order equation and find d mean a a a + d b h dmean + 5cm a + d hmin 35cm b

18 SIGLE FOOTIGS WITH AXIAL LOAD OLY G h b b a a Determination of footing dimensions güv, z g i b b b b + h b b BA g γ g g b b güv, z g T i A + T A b b g,güv z T i A net T i A net i T A Service loads are used for the determination of dimensions (G+Q)

19 SIGLE FOOTIGS / minimum dimensions l cantilever l cantilever h 5cm; h l cantilever / 4 b 70cm l cantilever l cantilever a l cantilever b 70cm a l cantilever b b must be higher than m b 70cm

20 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) V G o b / b / h a b Section - and - are shear and bending critical a b

21 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) o G H h o Check on plan dimensions of footing: Plan dimensions were determined considering the aial force onl. However, it must be checked if the are adequate or not in case of combined effect of (++H). The soil stress must be checked if it eceeds the ma. allowable stress of soil. Load case H z, em G+Q G+Q G+Q H G+Q.4G+.6Q.4G+.6Q.4G+.6Q H.4G+.6Q E E E H E Plan dimensions must be checked for the combination of (G+Q+E). If ma. allowable stress of the soil is eceeded then dimensions must be enlarged.

22 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) DIESIO CHECK FOR (G+Q+E) CASE G H o b / b / h G+Q + E G+Q + E H H G+Q + H E e O O + + O G Hh + Hh + G, + b b G µ 6 e b o b b, + b b b b W T 6 The ma. soil stress must be lower than the allowable soil stress ( z,em ). Otherwise dimensions must be increased. or G µ W T o

23 CHECK FOOTIG DIESIOS FOR BOTH X AD Y DIRECTIO USIG RELEVAT ITERAL ACTIOS Soil stress must be lower than z,em in case of G + Q E loading. Soil Tpe A.5 B.5 C.5 D.0

24 CALCULATIO OF ITERAL FORCES Plan dimensions of a single footing are determined using the service load (G+Q) since problem is solved based on the elastic theor. However, the internal forces to be used for the section design of a footing must be combined properl, since the section design is based on the ultimate strength theor. The load combinations are given b TS500;.4G+.6Q G+QE

25 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) H G h o b / b / Footing loads Load case H G+Q G+Q G+Q H G+Q.4G+.6Q.4G+.6Q.4G+.6Q H.4G+.6Q E E E H E

26 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) b ITERAL FORCES FOR OLY VERTICAL LOADS b.4g+.6q,.4g+.6q, H.4G+.6Q H O + Hh e O O + Hh G o b / b / h 6e, µ b b b, µ b b OR W T o o

27 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) G h o b / b / H (b - a )/ (/3)(b - a )/ (/)(b - a )/ ( ) ( ) ( ) ( ) ( ) k k b a b 3 a b a b a b + k

28 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) G o b / b / H h (b - a )/ k (/3)(b - a )/ (/)(b - a )/ b a b ( ) ( ) + k 4

29 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) G o b / b / H h (b - a )/ k V (/)(b - a )/ (/3)(b - a )/ ( b a ) a ( ) ( ) k k b + b

30 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) G o b / b / H h (b - a )/ k V (/3)(b - a )/ + (/)(b - a )/ ( b a ) k b

31 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) b ITERAL FORCES FOR VERTICAL LOADS + EARTHQUAKE LOAD b G+Q+E, G+Q+E, H G+Q+E H Load case H o b / b / h G+Q G+Q G+Q H G+Q.4G+.6Q.4G+.6Q.4G+.6Q H.4G+.6Q E E E H E

32 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) SECTIO DESIG.4G+.6Q -, V - -, V - G+Q+E -, V - -, V - The higher values are selected as the design internal forces for each direction.

33 SECTIO DESIG SECTIO (X-X) Section height: h Section width: b SECTIO (Y-Y) Section height : h Section height : b X b Section b b Section

34 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) Shear safet V Vcr, f b d ctd V Vcr, f b d ctd The shear safet must be checked for load combinations of.4g+.6q, G+QE, 0.9GE

35 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) Punching safet d G H h V d pd d ( a + d )( a + b b d d + d d ) z d b b a a + d a a + d b V pr γ f ctd ( a + a + d )d γ +.5 e e ( a + d )( a + d ) + b

36 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) d Punching safet G H h γ +.5 ( a + d )( a + d ) e + e z d b b e, e Eccentricit for the direction of and a a a + d b e 0.4 a + d b e 0.4

37 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) d H V Punching safet pr γ f ctd ( a + a + d )d G h V pd V pr z d b b The punching safet must be checked for both.4g+.6q and G+Q+E a a a + d b a + d b

38 FIXED SUPPORT FOOTIGS (,V,) (Smmetrical) d H V Punching safet pr γ f ctd ( a + a + d )d G h V pd V pr z d b b The punching safet must be checked for both.4g+.6q and G+QE a a a + d b a + d b

Design Beam Flexural Reinforcement

Design Beam Flexural Reinforcement COPUTERS AND STRUCTURES, INC., BERKELEY, CALIFORNIA DECEBER 2001 CONCRETE FRAE DESIGN ACI-318-99 Technical Note This Technical Note describes how this program completes beam design when the ACI 318-99