DISEO LOSA ALIGERADA PRIMER NIVEL

4.48 m 5.590 m 5.860 m 5.725 m 5.35 m

0.30 m 4.025 m 0.30 m 5.290 m 0.30 m 5.560 m 5.425 m 0.30 m 4.900 m 0.30 m

METRADO DE CARGAS:

Peso Propio de Losa. 350 kg/m2 = H=20 CM 0.70 m

Peso Piso y Cielo Razo: 100 kg/m2 =

Peso de Tabiqueria: 250 kg/m2 =

700 kg/m2 = Wcm= 0.700 Tn/m2 0.30 m

Sobrecarga: 300 kg/m2 = Wcv= 0.300 Tn/m2

Carga de Diseo:

Wu = 1.4 Wcm + 1.7 Wcv

CARGAS MAYORADAS: Wu = 1.490 Tn/m2

Wu = 1.490 Tn/m2

A B C D E F

4.025 m 5.290 m 5.560 m 5.425 m 4.900 m

A B C D E F

EMBOLVENTE :MOMENTOS MAXIMOS

-3.244 -3.844 -3.844 -4.101

-1.006 -1.491

A B C D E F

1.836 2.267 2.837 2.260 2.880

DISEO DE REFUERZO EN LA LOSA:

A)Para Momento Positivo: 2.880

bw=100cm f ' c = 210 Kg/cm2

f ' y = 4200 Kg/cm2

5 cm bw = 100.00 cm

rec. = 2.00 cm

Asumir = 1/220 cm d= 22.37 cm

Asumir que c = h f = 5.00 cm

25 cm a = c = 4.25 cm

Nota: Se calculara bw=100cm, Luego se dividira entre 2.5

3.76 cm2/m / 2.5 Area de Acero en 1 metro de Aligerado:

As = 4.95 cm2/m

= 1.16 cm

A cada vigueta le corresponde = 1.51 cm2

Usar : 1 1/2 1.27 cm2 c = 1.37 cm OK!

1 3/8 0.71 cm2

1.98 cm2 Por lo Tanto: Usar : 1 1/2 As = 1.98 cm2

1 3/8

.maxMu

)2

(9.0a

dfy

MuAs

bcf

fyAsa

'85.0

Calculo del Momento Resistente

= 4074.40 Kg-m/m

d = 22.37 cm2

RESUMEN :

TRAMO AB : As = 0.89 cm2 Usar : 1 1/2 1.27 cm2

0 3/8 0.00 cm2 1.27 cm2

TRAMO BC : As = 1.10 cm2 Usar : 1 1/2 1.27 cm2

0.00 cm2 1.27 cm2

TRAMO CD : As = 1.38 cm2 Usar : 1 1/2 1.27 cm2

1 3/8 0.71 cm2 1.98 cm2

TRAMO DE : As = 1.10 cm2 Usar : 1 1/2 1.27 cm2

0.00 cm2 1.27 cm2

TRAMO EF : As = 1.40 cm2 Usar : 1 1/2 1.27 cm2

1 3/8 0.71 cm2 1.98 cm2

B)Para Momento Negativo:

bw=100cm 4.101

5 cm f ' c = 210 Kg/cm2

f ' y = 4200 Kg/cm2

bw = 25.00 cm

20 cm rec. = 2.00 cm

Asumir = 1/2d= 22.37 cm

25 cm

Comprobando con las formulas de "a" y "As" tenemos:

Asumir valor de "a" A cada vigueta le corresponde = 2.19 cm2

)2

(*a

dfyAsM r

.maxMu

)2

(9.0a

dfy

MuAs

bcf

fyAsa

'85.0

a = 5.16 cm

As = 5.48 cm2 Usar : 2 1/2 2.53 cm2

a = 5.16 cm2 OK!

Calculo del Momento Resistente

= 4736.91 Kg-m/m d = 22.365

RESUMEN :

APOYO "A" As = 0.54 cm2 Usar : 1 1/2 '' 1.27 cm2

0 0.00 cm2 1.27 cm2

APOYO "B" As = 1.74 cm2 Usar : 1 1/2 '' 1.27 cm2

1 3/8 '' 0.71 cm2 1.98 cm2

APOYO "C" As = 2.06 cm2 Usar : 1 1/2 '' 1.27 cm2

1 1/2 '' 1.27 cm2 2.53 cm2

APOYO "D" As = 2.06 cm2 Usar : 1 1/2 '' 1.27 cm2

1 1/2 '' 1.27 cm2 2.53 cm2

APOYO "E" As = 2.19 cm2 Usar : 1 1/2 '' 1.27 cm2

1 1/2 '' 1.27 cm2 2.53 cm2

APOYO "F" As = 0.80 cm2 Usar : 1 1/2 '' 1.27 cm2

0 0.00 cm2 1.27 cm2

4.025 m 5.290 m 5.560 m 5.425 m 4.90 m

1.01 m 1.32 m 1.32 m 1.39 m 1.39 m 1.36 m 1.36 m 1.23 m

1 1 3/8 1 1/2 1 1/2 1 1/2 1

1/2 1/2

1 1/2 1 1/2 1 1/2 1 1/2

1.01 m 1.31 m 1.72 m 1.72 m 1.81 m 1.81 m 1.76 m 1.76 m 1.59 m 1.23 m

0 3/8 0 0 1 3/8 0 0 1 3/8

1 1/2 1 1/2 1 1/2 1 1/2 1 1/2

0.56 m 0.56 m 0.74 m 0.78 m 0.78 m 0.76 m 0.76 m 0.69 m 0.69 m

As.Temperatura=1/4"@25cm

VERIFICACION POR CORTANTE:

)2

(*a

dfyAsM r

V A V 'B V 'C V 'D V 'E

Vud

d

V ''B V ''C V ''D V ''E V F

En losas Vs = 0

(Mr)A (Mr)B (Mr)C (Mr)D (Mr)E (Mr)F

1 1/2 1 1/2 1 1/2 1 1/2 1 1/2 1 1/2

0 0 1 3/8 1 1/2 1 1/2 1 1/2 0 0

A B C D E F

4.025 m 5.290 m 5.560 m 5.425 m 4.900 m

a) Calculo de los Momentos Resistentes: Mr

1 1/2

MrA : (As)A = 0 0 = 3.17 cm2 f'c = 210 Kg/cm2

fy = 4200 Kg/cm2

= 2.98 cm b = 25.00 cm

rec. = 2.00 cm

d = 22.37 cm

MrB : (As)B = 1 1/2 = 4.95 cm2

= 2498.90 Kg-m/m

dbcfVud

VcVud

VsVcVn

VnVud

.*'53.0*

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rA

1 3/8

= 4.66 cm

MrC : (As)C = 1 1/2 = 6.33 cm2

1 1/2

= 5.96 cm

MrD : (As)D = 1 1/2 = 6.33 cm2

1 1/2

= 5.96 cm

MrE : (As)E = 1 1/2 = 6.33 cm2

1 1/2

= 5.96 cm

MrF : (As)F = 1 1/2 = 3.17 cm2

= 4640.99 Kg-m/m

= 4640.99 Kg-m/m

= 4640.99 Kg-m/m

= 3747.73 Kg-m/m

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rB

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rC

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rD

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rE

0 0

= 2.98 cm

b) Calculo de los Esfuerzos Cortantes: Vi

V A = 3308.89 Kg 3308.8934

V 'B = -2688.36 Kg 4142.20 Kg 2688.3566

V ''B = 4109.91 Kg 4109.90826

V 'C = -3772.19 Kg 3772.19174

V ''C = 4142.20 Kg 4142.2

V 'D = -4142.20 Kg 4142.2

V ''D = 4041.63 Kg 4041.625

V 'E = -4041.63 Kg 4041.625

V ''E = 3213.34 Kg 3213.33867

V F = -4087.66 Kg 4087.66133

3808.96 Kg

Corte que toma el Concreto

Vc = 4294.32 Kg

= 2498.90 Kg-m/m

i

jiiuii

L

MMLWV

2

Vud

d

Vmax.=

Vud

WudVuVud

dbcfVC **'*53.0

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rE

Vc = 3650.17 Kg CALCULAR ENSANCHE DE VIGUETA

Vud 3808.96 Kg

bw = 26.09 cm

Ensanche = 10.44 cm

0.11 cm

10.66 cm

10.44 cm

COMO L=10.66 cm Y b =10.44 cm ENTONCES SE DESPRECIARA EL ENSANCHE DE

VIGUETA

Ensanchar ViguetaViguetaEnsancharVcVudSi ..:

VuddbwcfV C **'*53.0.

dcf

Vudbw

*'53.0

LEnsanchedeLongitud :..

b=

L=

0.10

0.10

0.10