DISEO LOSA ALIGERADA SEGUNDO NIVEL

A B C D E F

4.48 m 5.590 m 5.860 m 5.725 m 5.35 m

4.025 m 5.290 m 5.560 m 5.425 m 4.900 m

METRADO DE CARGAS:

Peso Propio de Losa. 350 kg/m2 = 0.50 m

Peso Piso y Cielo Razo: 100 kg/m2 =

Peso de Cobertura Liviana: 25 kg/m2 =

475 kg/m2 = Wcm= 0.475 Tn/m2 0.30 m

Sobrecarga: 50 kg/m2 = Wcv= 0.050 Tn/m2

Carga de Diseo:

Wu = 1.4 Wcm + 1.7 Wcv

CARGAS MAYORADAS: Wu = 0.750 Tn/m2

Wu = 0.750 Tn/m2

A B C D E F

4.025 m 5.290 m 5.560 m 5.425 m 4.900 m

EMBOLVENTE :MOMENTOS MAXIMOS

-1.633 -1.892 -1.865 -2.064

-0.506 -0.750

A B C D E F

0.848 0.962 1.173 0.920 1.374

DISEO DE REFUERZO EN LA LOSA:

A)Para Momento Positivo: 1.374

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

f ' y = 4200 Kg/cm2

5 cm bw = 100.00 cm

rec. = 2.00 cm

Asumir = 1/215 cm d= 17.37 cm

Asumir que c = h f = 5.00 cm

25 cm a = c = 4.25 cm

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

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

As = 3.17 cm2/m

= 0.75 cm

A cada vigueta le corresponde = 0.95 cm2

Usar : 1 1/2 1.27 cm2 c = 0.88 cm OK!

0 3/8 0.00 cm2 Usar : 1 1/2 As = 1.27 cm2

1.27 cm2 Por lo Tanto: 0 3/8

.maxMu

)2

(9.0a

dfy

MuAs

bcf

fyAsa

'85.0

Calculo del Momento Resistente

= 2034.16 Kg-m/m

d = 17.37 cm2

RESUMEN :

TRAMO AB : As = 0.53 cm2 Usar : 1 1/2 1.27 cm2

0 3/8 0.00 cm2 1.27 cm2

TRAMO BC : As = 0.60 cm2 Usar : 1 1/2 1.27 cm2

0.00 cm2 1.27 cm2

TRAMO CD : As = 0.73 cm2 Usar : 1 1/2 1.27 cm2

0.00 cm2 1.27 cm2

TRAMO DE : As = 0.57 cm2 Usar : 1 1/2 1.27 cm2

0.00 cm2 1.27 cm2

TRAMO EF : As = 0.86 cm2 Usar : 1 1/2 1.27 cm2

0 3/8 0.00 cm2 1.27 cm2

B)Para Momento Negativo:

bw=100cm 2.064

5 cm f ' c = 210 Kg/cm2

f ' y = 4200 Kg/cm2

bw = 25.00 cm

15 cm rec. = 2.00 cm

Asumir = 1/2d= 17.37 cm

25 cm

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

)2

(*a

dfyAsM r

.maxMu

)2

(9.0a

dfy

MuAs

bcf

fyAsa

'85.0

Asumir valor de "a" A cada vigueta le corresponde = 1.39 cm2

a = 3.27 cm

As = 3.47 cm2 Usar : 2 3/8 1.43 cm2

a = 3.27 cm2 OK!

Calculo del Momento Resistente

= 2139.79 Kg-m/m d = 17.52375

RESUMEN :

APOYO "A" As = 0.34 cm2 Usar : 1 1/2 '' 1.27 cm2

0 0.00 cm2 1.27 cm2

APOYO "B" As = 1.09 cm2 Usar : 1 1/2 '' 1.27 cm2

0 3/8 '' 0.00 cm2 1.27 cm2

APOYO "C" As = 1.26 cm2 Usar : 1 1/2 '' 1.27 cm2

0 3/8 '' 0.00 cm2 1.27 cm2

APOYO "D" As = 1.24 cm2 Usar : 1 1/2 '' 1.27 cm2

0 3/8 '' 0.00 cm2 1.27 cm2

APOYO "E" As = 1.37 cm2 Usar : 1 1/2 '' 1.27 cm2

1 3/8 '' 0.71 cm2 1.98 cm2

APOYO "F" As = 0.50 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 0 3/8 0 3/8 0 3/8 1 3/8 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 0 0 0 0 0 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

)2

(9.0a

dfy

MuAs

)2

(*a

dfyAsM r

VERIFICACION POR CORTANTE:

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 0 3/8 0 3/8 0 3/8 1 3/8 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 = 17.37 cm

= 1900.35 Kg-m/m

dbcfVud

VcVud

VsVcVn

VnVud

.*'53.0*

bcf

fyAsa

'85.0

)2

(.a

dfyAsM rA

MrB : (As)B = 1 1/2 = 3.17 cm2

0 3/8

= 2.98 cm

MrC : (As)C = 1 1/2 = 3.17 cm2

0 3/8

= 2.98 cm

MrD : (As)D = 1 1/2 = 3.17 cm2

0 3/8

= 2.98 cm

MrE : (As)E = 1 1/2 = 4.95 cm2

1 3/8

= 4.66 cm

= 1900.35 Kg-m/m

= 1900.35 Kg-m/m

= 2812.50 Kg-m/m

= 1900.35 Kg-m/m

)2

(.a

dfyAsM rA

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

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

0 0

= 2.98 cm

b) Calculo de los Esfuerzos Cortantes: Vi

V A = 1509.38 Kg 1509.375

V 'B = -1509.38 Kg 2202.51 Kg 1509.375

V ''B = 1983.75 Kg 1983.75

V 'C = -1983.75 Kg 1983.75

V ''C = 2085.00 Kg 2085

V 'D = -2085.00 Kg 2085

V ''D = 2202.51 Kg 2202.51269

V 'E = -1866.24 Kg 1866.23731

V ''E = 1651.35 Kg 1651.34756

V F = -2023.65 Kg 2023.65244

2072.28 Kg

Corte que toma el Concreto

Vc = 3334.27 Kg

= 1900.35 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 = 2834.13 Kg OK!

bw =

Ensanche =

POR LO TANTO NO ES NECESARIO CALCULAR ENSANCHE DE VIGUETA

ViguetaEnsancharVcVudSi ..:

VuddbwcfV C **'*53.0.

dcf

Vudbw

*'53.0

LEnsanchedeLongitud :..

b=

L=

0.10

0.10

0.10