67
3,80 1,90
1,90
1,80
1,80
2,30 3,70
4.2 Perencanaan Tangga
1. Ketentuan dan Dimensi Tangga
- Skema tangga
- Tinggi lokal ruangan
= 3,80 m -
Ruangan tersedia = 3,6 x 6 m
- Tinggi dasar sampai bordes = 1,90 m
B o
r d
e s
68
- Anak tangga
• Tinggi optride t = 17 sd 19
Diambil 18 cm •
Jumlah anak tangga =
18 380
= 21,11 dibulatkan 22 buah •
Lebar antride a + 2 o = 60 sd 66 dipakai lebar antrede = 66
a = 66 – 2x18 = 30 cm
- Kemiringan tangga
α = arc tg
55 ,
3 90
, 1
= 28
2. Penulangan plat bordes
Momen Rancang Plat β =
3 ,
2 6
, 3
= 1,6 cx+ = 49
cx- = 78 cy+ = 15
cy- =
54
Mtx = -cx . 0,001 . Wu . Lx
2
Mtx = -78 . 0,001. 9,912 . 2,3
2
Mtx = -4,09 kNm 2300
3600
69
Mlx = +cx . 0,001 . Wu . Lx
2
Mlx = +59 . 0,001. 9,912 . 2,3
2
Mlx = 2,57 kNm
Mty = -cy . 0,001 . Wu . Lx
2
Mty = -54 . 0,001. 9,912 . 2,3
2
Mty = -2,83 kNm
Mly = +cy . 0,001 . Wu . Lx
2
Mly = +15 . 0,001. 9,912 . 2,3
2
Mly = 0,79 kNm Penulangan Plat
• Tebal Plat = 150 mm
• Selimut Beton = p = 20 mm
Direncanakan ¾
Diameter tulangan utama arah x = φ10 mm
¾ Diameter tulangan utama arah y =
φ10 mm Tinggi efektif
- Arah x = dx = h – p –Dx2 = 150 – 20 – 102
= 125 mm - Arah y = dy = h – p – Dx – Dy2
= 150 – 20 – 10 – 102 = 115 mm
70
Dy
h
Dx dy
dx
Penulangan tepi arah x
Ditinjau 1000 mm Mtx = 4,09 kNm
k =
2
xbxd Mu
φ =
2
125 1000
8 ,
4090000 x
x = 0,327
Dari Tabel Beton Apendiks pada bagian tabel A-10 maka
ρ = 0,0058 As tx
1
= xbxd ρ
= 0,0058 x 1000 x 125 = 725 mm
2
Direncanakan tulangan φ 10 mm
As = ¼ x π x D
2
= ¼ x 3,14 x 10
2
= 78,5 mm
2
Jumlah tulangan n =
As Astx
1
n = 5
, 78
725 = 9,24 dibulatkan 10 batang
Spasi =
1 −
n b
=
9 1000mm
= 111,11 mm dibulatkan 110 mm
71
Dipakai tulangan φ 10 – 110 mm
As tx
2
= As x n = 78,5 mm
2
x 10 = 785 mm
2
As tx
1
= 725 mm
2
Tulangan memenuhi syarat
Penulangan lapangan arah x
Ditinjau 1000 mm
Mlx = 2,57 kNm k =
2
xbxd Mu
φ =
2
125 1000
8 ,
2570000 x
x = 0,206
Dari Tabel Beton Apendiks pada bagian tabel A-10 maka
ρ = 0,0058 As tx
1
= xbxd ρ
= 0,0058 x 1000 x 125 = 725 mm
2
Direncanakan tulangan φ 10 mm
As = ¼ x π x D
2
= ¼ x 3,14 x 10
2
= 78,5 mm
2
Jumlah tulangan n =
As Astx
1
n = 5
, 78
725 = 9,24 dibulatkan 10 batang
Spasi =
1 −
n b
=
9 1000mm
= 111,11 mm dibulatkan 110 mm
72
Dipakai tulangan φ 10 – 110 mm
As tx
2
= As x n = 78,5 mm
2
x 10 = 785 mm
2
As tx
1
= 725 mm
2
Tulangan memenuhi syarat
Penulangan tepi arah y
Ditinjau 1000 mm Mty = 2,83 kNm
k =
2
xbxd Mu
φ =
2
115 1000
8 ,
2830000 x
x = 0,267
Dari Tabel Beton Apendiks pada bagian tabel A-10 maka
ρ =0,0058 As tx
1
= xbxd ρ
= 0,0058 x 1000 x 115 = 667 mm
2
Direncanakan tulangan φ 10 mm
As = ¼ x π x D
2
= ¼ x 3,14 x 10
2
= 78,5 mm
2
Jumlah tulangan n =
As Astx
1
n = 5
, 78
667 = 8,5 dibulatkan 9 batang
Spasi =
1 −
n b
=
8 1000mm
= 125 mm
73
Dipakai tulangan φ 10 – 125 mm
As tx
2
= As x n = 78,5 mm
2
x 9 = 706,5 mm
2
As tx
1
= 667 mm
2
Tulangan memenuhi syarat
Penulangan lapangan arah y
Ditinjau 1000 mm Mly = 0,79 kNm
k =
2
xbxd Mu
φ =
2
115 1000
8 ,
790000 x
x = 0,075
Dari Tabel Beton Apendiks pada bagian tabel A-10 maka
ρ =0,0058 As tx
1
= xbxd ρ
= 0,0058 x 1000 x 115 = 667 mm
2
Direncanakan tulangan φ 10 mm
As = ¼ x π x D
2
= ¼ x 3,14 x 10
2
= 78,5
mm
2
Jumlah tulangan n =
As Astx
1
n = 5
, 78
667 = 8,5 dibulatkan 9 batang
Spasi =
1 −
n b
=
8 1000mm
= 125 mm
74
Dipakai tulangan φ 10 – 125 mm
As tx
2
= As x n = 78,5 mm
2
x 9 = 706,5 mm
2
As tx
1
= 667 mm
2
Tulangan memenuhi syarat
3. Penulangan plat tangga