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277
S =
3824 ,
289 24500
294 240
48 ,
100 perlu
Vs d
. fy
. Av
mm S max = d2 =
2 294
= 147 ~ 150 mm 600 mm
Jadi dipakai sengkang dengan tulangan Ø 8 150 mm
Tul. Tumpuan Tul. Lapangan
7.7. Penulangan Balok Portal
7.7.1. Perhitungan Tulangan Lentur Balok Portal Memanjang
Data perencanaan : h = 750 mm
b = 400 mm p = 40 mm
fy = 390 Mpa = 25 MPa
Ø
t
= 22 mm Ø
s
= 10 mm d = h - p - Ø
s
- ½.Ø
t
= 700 40 10 - ½.22 = 689 mm
25 25
3 D 16
2 D 16 Ø8 - 150
2 D 16
2 D 16 Ø8 - 150
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278
b =
fy 600
600 fy
c. 0,85.f
= 390
600 600
85 ,
390 25
. 85
, = 0,0281
max
= 0,75 . b = 0,75 . 0,0281
= 0,021
min
= 0036
, 390
4 ,
1 4
, 1
fy
Daerah Tumpuan Dari Perhitungan SAP 2000 diperoleh momen terbesar pada batang nomor 276 :
Mu = 61004,17
kgm = 6,100417 × 10
8
Nmm Mn =
Mu =
8 ,
10 100017
, 6
8
= 7,63 × 10
8
Nmm Rn =
02 ,
4 689
400 10
7,63 d
. b
Mn
2 8
2
m = 35
, 18
25 0,85
390 c
0,85.f fy
= fy
2.m.Rn 1
1 m
1
= 390
02 ,
4 35
, 18
2 1
1 35
, 18
1 = 0,0115
min max
dipakai tulangan tunggal Digunakan
= 0,0120 As perlu = . b . d
= 0,0115 × 400 × 689 = 3169,40 mm
2
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279
Digunakan tulangan D 22 n
= 94
, 379
3169,40 22
. 4
1 perlu
As
2
= 8,34 9 tulangan =
2
22 .
4 1
=
2
19 .
14 ,
3 4
1 = 379,94 mm
As ada = 9 × 379.94 = 3419,46 mm
2
Aman Ok
Cek jarak =
1 -
n t
- s
2 -
p 2
- b
1 -
9 .22
9 -
2.10 -
2.40 -
400
= 12,75 mm 25 mm dipakai tulangan 2 lapis d1
=689 mm d2
= 689 30 -11 = 648 mm
d =
9 648
x 3
689 x
6 = 675,33 mm
a =
400 25
85 ,
390 3419,46
b c
f 0,85
fy ada
As = 156,89
Mn ada = As ada × fy d -
2 a
= 3419,46 × 390 675,33 -
2 156,89
= 7,96 . 10
8
Nmm
commit to user
280
Mn ada Mn ......... Aman
Jadi dipakai tulangan 9 D 22 Daerah Lapangan
Dari Perhitungan SAP 2000 diperoleh momen terbesar pada batang nomor 276.
Mu = 51963,36 kgm = 5,196336 × 10
8
Nmm Mn =
Mu =
8 ,
10 5,196336
8
= 6,50 × 10
8
Nmm Rn =
42 ,
3 689
400 10
6,50 d
. b
Mn
2 8
2
m = 35
, 18
25 0,85
390 c
0,85.f fy
= fy
2.m.Rn 1
1 m
1
= 390
42 ,
3 35
, 18
2 1
1 35
, 18
1 = 0,00962
min max
dipakai tulangan tunggal Digunakan = 0,00962
As perlu = . b . d = 0,00962 × 400 × 689
= 2650,71 mm
2
Digunakan tulangan D 19 n
= 94
, 379
2650,71 22
. 4
1 perlu
As
2
= 6,98 8 tulangan =
2
22 .
4 1
=
2
19 .
14 ,
3 4
1 = 379,94 mm
As ada = 8 × 379.94 = 3039,52 mm
2
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281
Aman Ok
Cek jarak =
1 -
n t
- s
2 -
p 2
- b
1 -
8 22
8. -
2.10 -
2.40 -
450 = 24,85 mm 25 mm dipakai tulangan 2 lapis
d1 =689 mm
d2 = 689 30 -11
= 648 mm d
=
8 649
x 2
689 x
6 = 679 mm
a =
400 25
85 ,
390 3039,52
b c
f 0,85
fy ada
As = 139,46
Mn ada = As ada × fy d -
2 a
= 3039,52 × 390 679 -
2 139,46
= 7,22 . 10
8
Nmm Mn ada Mn ......... Aman
Jadi dipakai tulangan 8 D 22 7.7.2. Perhitungan Tulangan Geser Portal Memanjang
Dari Perhitungan SAP 2000 diperoleh momen terbesar pada batang nomor 276:
Vu = 36638,48 kg = 366384,8 N
= 25 Mpa fy
= 390 Mpa d
= 689 mm Vc
= 1 6 . c
f .b .d
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282
= 1 6 . 25 .400.689 = 229666,67 N
Vc = 0,75 . 229666,67 = 172250,00 N
3 Vc = 3 . 172250,00 = 516750 N Syarat tulangan geser : Ø Vc Vu 3 Ø Vc
: 172250,00 N 366384,8 N 516750 N Jadi diperlukan tulangan geser
Ø Vs = Vu Ø Vc
= 366384,48 - 172250,00 = 194134,48 N
Vs perlu =
75 ,
194134,48 75
, Vs
= 258845,97 N Av
= 2 . ¼ 10
2
= 2 . ¼ . 3,14 . 100 = 157 mm
2
S =
98 ,
162 258845,97
689 .
390 .
157 perlu
Vs d
. fy
. Av
mm S max = d2 =
2 639
= 319,5 mm
Jadi dipakai sengkang dengan tulangan Ø 10 150 mm Potongan balok portal memanjang
Tul. Tumpuan Tul. Lapangan
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283
7.7.3. Perhitungan Tulangan Lentur Balok Portal Melintang
