viga principal 9-15
DESCRIPTION
aaaTRANSCRIPT
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DISEO DE VIGA PRINCIPAL 25X45 (b*h)
DATOS
h = 45 cm Peralte de la viga
b = 25 cm Base de la viga
L = 3.40 m Long. De viga entre eje
d = 39 cm Peralte efectivo
d'= 6 cm d=39cm
MOMENTO ULTIMO(calculo primera parte del trabajo) h=45cm
Mu(+)= 11.526 Tn-m Mu(-)= 16.822 Tn-m
Mu(+)= 1.482 Tn-m Mu(-)= 17.686 Tn-m
Mu(+)= 10.300 Tn-m
ESPECIFICACIONES
f'c = 210 Kgr/cm2 Esfuerzo ala compresion del concreto b=25cm
fy = 4200 Kgr/cm2 Esfuerzo de fluencia del acero
DIAGRAMA DE MOMENTO DE LA VIGA A DISEAR DATO ANLISIS (Kg-m)
As=?r
d'As'=?
PARA EL EJEMPLO SE TOMARA LA VIGA 9-15
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VERIFICACIN DE CUANTIAS
CUANTIA MAXIMA
0.85 x 0.85 x 210 x 0.59 = 0.0214
4200
0.75 x 0.0214187 = 0.0161
CANTIDA DE ACERO MAXIMO
0.0161 x 25 x 39 = 15.66 cm2
ACERO MINIMO
14x 25 x 39 =3.25 cm2
4200
0.7 x 210 x 25.0 x 39. = 2.35 cm2
4200
CALCULO DE LAS AREAS DE ACERO
ACERO POSITIVO MU(+)
= 11.53 Tn-m
POR TANTEO
primer tanteo con a = 6.00 cm
11.53 = 8.47 cm2 8.47 x 4200 = 7.97 cm
0.9 x 4200 x 36.00 0.85x210 x 25.
segundo tanteo a = 7.97 cm
11.53 = 8.71 cm2 8.71 x 4200 = 8.20 cm
0.9 x 4200 x 35 0.85x210 x 25
tercer tanteo a = 8.20 cm
11.53 = 8.74 cm2 8.74 x 4200 = 8.22 cm
0.9 x 4200 x 35 0.85x210 x 25
cuarto tanteo a = 8.22 cm
11.53 = 8.74 cm2 8.74 x 4200 = 8.23 cm
0.9 x 4200 x 35 0.85x210 x 25
quinto tanteo a = 8.23 cm
11.53 = 8.74 cm2 8.74 x 4200 = 8.23 cm
0.9 x 4200 x 35 0.85x210 x 25
sexto tanteo a = 8.23 cm
11.53 = 8.74 cm2 8.74 x 4200 = 8.23 cm
0.9 x 4200 x 35 0.85x210 x 25
SE DEBE VERIFICAR
Asmax > As
15.66 > 8.74 cm2 NO REQUIRE ACERO EN COMPRESION
As(+)
= 8.74 cm2
2 5/8'' + 2 3/4'' =9.66 cm2 ..........Ok
dbAs maxmax
fyfy
cfb
6117
6117'85.0 1
bMAX 75.0
2
adfy
MuAs
dbfy
As14
min
2
adfy
MuAs
bfc
fyAsa
'85.0
bfc
fyAsa
'85.0
fy
dbcfAs
'8.0min
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
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ACERO POSITIVO MU(+)
= 1.48 Tn-m
ACERO MINIMO
14x 25 x 39 =3.25 cm2
4200
3.25 x 4200 = 3.06 cm
0.85 x 210 x 25.
0.9x3.25 x 4200 x 37.47 = 4.60 Tn-m
Entonces para este caso se asumira acero minimo ya que el momento minimo es mayor al mometo a disear
Mu > Mu(min)
1.48 < 4.60 Tn-m DISEE CON ACERO MINIMO..........Ok
As(+)
= 3.25 cm2
2 3/4'' + 0 0 '' =5.70 cm2 ..........Ok
ACERO POSITIVO MU(+)
= 10.30 Tn-m
POR TANTEO
primer tanteo con a = 10.00 cm
10.30 = 8.01 cm2 8.01 x 4200 = 7.54 cm
0.9 x 4200 x 34.00 0.85x210 x 25.
segundo tanteo a = 7.54 cm
10.30 = 7.73 cm2 7.73 x 4200 = 7.28 cm
0.9 x 4200 x 35.23 0.85x210 x 25.
tercer tanteo a = 7.28 cm
10.30 = 7.71 cm2 7.71 x 4200 = 7.25 cm
0.9 x 4200 x 35.36 0.85x210 x 25.
cuarto tanteo a = 7.25 cm
10.30 = 7.70 cm2 7.70 x 4200 = 7.25 cm
0.9 x 4200 x 35.37 0.85x210 x 25.
quinto tanteo a = 7.25 cm
10.30 = 7.70 cm2 7.70 x 4200 = 7.25 cm
0.9 x 4200 x 35.38 0.85x210 x 25.
sexto tanteo a = 7.25 cm
10.30 = 7.70 cm2 7.70 x 4200 = 7.25 cm
0.9 x 4200 x 35.38 0.85x210 x 25.
septimo tanteo a = 7.25 cm
10.30 = 7.70 cm2 7.70 x 4200 = 7.25 cm
0.9 x 4200 x 35.38 0.85x210 x 25.
SE DEBE VERIFICAR
Asmax > As
15.66 > 7.70 cm2 NO REQUIRE ACERO EN COMPRESION
As(+)
= 7.70 cm2
2 5/8'' + 2 5/8'' =7.92 cm2 ..........Ok
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
dbfy
As14
min
bcf
fyAsa
'85.0
min
2
mina
dfyAscMU
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ACERO NEGATIVO MU(-)
= 16.82 Tn-m
POR TANTEO
primer tanteo con a = 10.00 cm
16.82 = 13.09 cm2 13.09 x 4200 = 12.32 cm
0.9 x 4200 x 34.00 0.85x210 x 25.
segundo tanteo a = 12.32 cm
16.82 = 13.55 cm2 13.55 x 4200 = 12.75 cm
0.9 x 4200 x 33 0.85x210 x 25
tercer tanteo a = 12.75 cm
16.82 = 13.64 cm2 13.64 x 4200 = 12.84 cm
0.9 x 4200 x 33 0.85x210 x 25
cuarto tanteo a = 12.84 cm
16.82 = 13.66 cm2 13.66 x 4200 = 12.86 cm
0.9 x 4200 x 33 0.85x210 x 25
quinto tanteo a = 12.86 cm
16.82 = 13.66 cm2 13.66 x 4200 = 12.86 cm
0.9 x 4200 x 33 0.85x210 x 25
sexto tanteo a = 12.86 cm
16.82 = 13.66 cm2 13.66 x 4200 = 12.86 cm
0.9 x 4200 x 33 0.85x210 x 25
SE DEBE VERIFICAR
Asmax > As
15.66 > 13.66 cm2 NO REQUIRE ACERO EN COMPRESION
As(-)
= 13.66 cm2
2 3/4'' + 3 3/4'' =14.25 cm2 ..........Ok
ACERO NEGATIVO MU(-)
= 17.69 Tn-m
POR TANTEO
primer tanteo con a = 10.00 cm
17.69 = 13.76 cm2 13.76 x 4200 = 12.95 cm
0.9 x 4200 x 34.00 0.85x210 x 25.
segundo tanteo a = 12.95 cm
17.69 = 14.39 cm2 14.39 x 4200 = 13.54 cm
0.9 x 4200 x 33 0.85x210 x 25
tercer tanteo a = 13.54 cm
17.69 = 14.52 cm2 14.52 x 4200 = 13.66 cm
0.9 x 4200 x 32 0.85x210 x 25
cuarto tanteo a = 13.66 cm
17.69 = 14.54 cm2 14.54 x 4200 = 13.69 cm
0.9 x 4200 x 32 0.85x210 x 25
quinto tanteo a = 13.69 cm
17.69 = 14.55 cm2 14.55 x 4200 = 13.69 cm
0.9 x 4200 x 32 0.85x210 x 25
dbAS ''dbA S MAX 55.0'
2
adfy
MuAs
2
adfy
MuAs
bfc
fyAsa
'85.0
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
2
adfy
MuAs
bfc
fyAsa
'85.0
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
2
adfy
MuAs
bfc
fyAsa
'85.0
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sexto tanteo a = 13.69 cm
17.69 = 14.55 cm2 14.55 x 4200 = 13.70 cm
0.9 x 4200 x 32 0.85x210 x 25
SE DEBE VERIFICAR
Asmax > As
15.66 > 14.55 cm2 NO REQUIRE ACERO EN COMPRESION
As(-)
= 14.55 cm2
2 3/4'' + 3 3/4'' =14.25 cm2 ..........Ok
9 15
3.40m
3 3/4'' 3 3/4''
3 3/4''
0.90m 0.90m
2 5/8''
2 3/4'' 2 3/4''
POR PROCESO CONSTRUCTIVO SE UTILIZARA
2 3/4'' + 3 3/4'' 3 3/4'' + 2 3/4'' + 3 3/4''
0.45m 0.45m 0.45m
O
0.25m 0.25m 0.25m
2 5/8'' + 2 3/4'' 2 5/8'' + 2 5/8'' + 2 3/4''
SECCION A - A SECCION B - B SECCION C - C
A
A
B
B
C
C
2
adfy
MuAs
2
adfy
MuAs
bfc
fyAsa
'85.0