Losa Nervada en Dos Direcciones

1. REPÚBLICA BOLIVARIANA DE VENEZUELA
INSTITUTO UNIVERSITARIO POLITÉCNICO
“SANTIAGO MARIÑO”
CARRERA: ING. CIVIL (42)
SEDE-BARCELONA
Profesor: Bachiller:
Ing.Hector Aguana Jorge Sanchez
C.I: 22840050
Seccion:Lv
Barcelona,12 de Mayo del 2013

2. Vivienda Losa nervada
7.5 5 6 7 8 1/2
7.5 1 2 3 4 1/2
3.7 3.7 3.7 3.7 1.5
F´c=300
𝑘𝑔
𝑐𝑚2⁄
r = 8cm
F’y = 4200
𝑘𝑔
𝑐𝑚2⁄
Carga variable = 180
𝑘𝑔
𝑚2⁄
L1 = L/18 = 3.7/18 = 0.17cm
L2 = L/21 = 3.7/21 = 0.15cm
L3 = L/21 = 3.7/21 = 0.15cm
L4 = L/21 = 3.7/21 = 0.15cm
L5 = L/8 = 1.5/8 = 0.18cm
Peso propio
𝑷. 𝑷 = 0.21 × 2600 = 546
𝑘𝑔
𝑚2⁄

3. SOBRE
PISO
3cm
6cm
LOSA 118cm
FRISO 4cm
 Cerámica = 2x22 =44
 Sobre piso = 0.06x1800=108
 Peso Propio =0.18x2600=468
 Friso = 0.04x1900=60
∑ = 774 kg/𝑐𝑚2
Peso variable :
P.V = 1.4 x 774+1.7 x180 = 1389.6
𝑘𝑔
𝑚2⁄
Carga permanente = 774
𝑘𝑔
𝑚2⁄
Carga variable = 1389.6
𝑘𝑔
𝑚2⁄
q= 1188.8
𝑘𝑔
𝑚2⁄
𝑞 𝑥 𝐿𝑛2
10
𝑞 𝑥 𝐿𝑛2
11
𝑞 𝑥 𝐿𝑛2
11
𝑞 𝑥 𝐿𝑛2
2
𝑞𝐿2
11
𝑞𝐿2
16
𝑞𝐿2
16
𝑞𝐿2
16
Negativos
Negativos

4. 1)
3.7+3.7
2 = 3.7 = 1188.8(3.7)
2
10 = 1902.36
2)
3.7+3.7
2 = 3.7 = 1188.8(3.7)
2
11 = 1729.42
3)
3.7+3.7
2 = 3.7 = 1188.8(3.7)
2
11 = 1729.42
4)
1389.6(1.5)
2
2 = 1563.3
Positivos
Mu1=
1389.6(3.7)2
11
= 1729.42
Mu2=
1389.6(3.7)2
16
= 1188.97
Mu3=
1389.6(3.7)2
16
= 1188.97
Mu4=
1389.6(3.7)2
16
= 1188.97
Reacciones Isostáticas 1389.6
A 3.7 B

5. ∑Fy= 0
D+E =1389.6(3.7 +1.5)
D+E =5141.52+2084.4 = 7225.92
∑Md=0
1389.6(3.7+1.5)+3.5=0
1389.6(3.7+1.2)= 4508.68
7.4
Hiperestáticas
1454.3
1454.3 =393.05
3.7 3.7
1207.55
1207.55 = 326.36
3.7 3.7

6. 1454.3 =393.05 1454.3= 393.05
3.7 3.7
1207.55 =326.36
1207.55=326.36 3.7
3.7
66.69 66.69
1454.3x100=145430
1207.55x 100= 120755
1563.3x 100= 156330
Calcular m
M =
𝑀𝑢
𝐹′𝑐.𝑏.𝑑2
M =
145430
300𝑥100𝑥102 = 0.048

7. Area de Acero
As=
𝑀
0.9𝑥𝐹′𝑦𝑥𝐽𝑢𝑥10
Momentos negativos
 Mmax A =
1454.3
0.9𝑥4200𝑥0.971𝑥10
= 0.03
 Mmax B =
1207.55
0.9𝑥4200𝑥0.971𝑥10
= 0.032
 Mmax C =
1563.3
0.9𝑥4200𝑥0.971𝑥10
= 0.042
Calcular Acero Mínimo
 Asmin =
14𝑥 𝑏 𝑥𝑑
4200
 Asmin =
14𝑥 100 𝑥 10
4200
= 3.33 𝑐𝑚2

8. 0.62 0.375 0.62 0,375 0.375
5∅ 𝑁3 8∅𝑁3 5∅𝑁5 8∅𝑁3 8∅𝑁3