Tugas Besar

BAB IIIPERENCANAAN PELAT LANTAI DAN ATAP

PERENCANAAN DAN PERHITUNGAN PELAT

1. PEMBEBANAN PADA PELATA. Pelat Atap

Beban mati- Berat sendiri = 0.12 m x 2400 kg/m3

=288 kg/m2

- Berat Plafond + Rangka =7 kg/m2 + 11 kg/m2 =18 kg/m2

- Berat Sanitasi & Plumbing =20 kg/m2 x 10 kg/m2 =30kg/m2

- Berat finishing (1cm) =21kg/m2

Pd total=357kg/m2

Beban hidup- Berat Hidup Atap PL= 287kg/m2

Kombinasi beban =1.2PD+1.6PL = 888kg/m2

B. Pelat LantaiBerat Mati- Berat sendiri = 0.12 m x 2400 kg/m3

=288 kg/m2

- Berat Plafond + Rangka =7 kg/m2 + 11 kg/m2 =18 kg/m2

- Berat Sanitasi & Plumbing =20 kg/m2 x 10 kg/m2 =30kg/m2

- Berat finishing (2cm) =2 x 21 kg/m2

=42kg/m2

- Berat Keramik =5kg/m2

Pdtotal=383 kg/m2

Tugas Besar

Berat hidup- Berat lantai PL=718 kg/m2 Kombinasi Beban=1.2Pd+1.6PL= 1609 kg/m2

2. PERHITUNGAN PELAT DATA PELAT- Tebal Pelat atap = 0.12 m- Selimut Beton = 20 mm - Tulangan Rencana atap = 12 mm- Tulangan Rencana lantai = 16 mm - Mutu Baja(fy) = 350 Mpa =3500kg/cm2- Mutu Beton(fc) = 35 Mpa =350 kg/cm2- dx= 120 cm – 20 – 12/2 cm = 94 mm- dy =120cm– 20 – 12 – ½ (12 )= 82 mm

PERHITUNGANTahapan yang digunakan dalam menentukan tulangan lentur plat adalah sebagai berikut:

1. Menentukan data-data d, fy, fc’, dan Mu2. Menentukan batasan harga tulangan dengan menggunakan

rasio tulangan yang disyaratkan sebagai berikut :

ρb=0.85β1fc'fy ( 600

600+fy)ρmax=0.75ρb

ρmin=0,25√f'cfy

3. Hitung rasio tulangan yang dibutuhkan :

ρ=1m (1−√1−2×m×Rn

fy )4. Menentukan luas tulangan (AS) dari ῤ yang didapatρ= As

bxd

Tugas Besar

0 28 56 840.600000000000001

0.650000000000001

0.700000000000001

0.750000000000001

0.800000000000001

0.850000000000001

0.900000000000002

NILAI β1

NILAI β1

β1 = 0,85 – 0,05(fc'−28

7 ) pasal 10.2.7.3 SNI 2847 2013Fc=35 Mpa >28 maka β1 = 0,85 – 0,05

(fc'−287 ) = 0,85 – 0,05 (35−287 ) =

0,8

ρbnce =

0,85×β1×fc'fy ×(600600+fy ) =

0,85×0,8×35350

×(600600+350 ) = 0,043ρmax 0,75 x ρbalance = 0,75 x 0,043 = 0.032

min =

0,25√f'cfy =

1,4350 √35

= 0.0043

m=fy

0.85fc'=3500.85x35

=11,77

Dalam perhitungan penulangan pelat jika Ly/Lx<2 lihat PBI 1971 tabel

13.3.2 maka di dapat rumus momen sebagai berikut:

Mlx = 0.001 . qu . Lx2 . X

Mtx = -0.001 . qu . Lx2 . X

Mly = 0.001 . qu . Lx2 . X

Mty = -0.001 . qu . Lx2 . X

Tugas Besar

Mlx = momen lentur pelat per satuan panjang di lapangan di arah

bentang lx.

Mly = momen lentur pelat per satuan panjang di lapangan di arah

bentang ly.

Mtx = momen lentur pelat per satuan panjang di tumpuan di arah

bentang lx.

Mty = momen lentur pelat per satuan panjang di tumpuan di arah

bentang ly.

1

2

Tugas Besar

Lx = 360 cm

Ly = 565 cm

Tugas Besar

A. PELAT ATAP TYPE 1 UKURAN (4 m x 6 m)40/60

35/50 35/50

40/60

Ly= 600-2(30/2)=565 cmLx=400-2(40/2)=360 cm

PBI 1971 tabel 13.3.2 didapat persamaan momen sebagai berikut : (Iy/Ix

= 1,6)( b=1000mm)

Mlx nilai X = 37

Mtx nilai X = 79

Mly nilai X = 16

Mty nilai X = 57

Mlx = 0.001 . qu . Lx2 . X = 0.001 x 888 x 3,62 x 37 = 426 kgm

Mtx = -0.001 . qu . Lx2 . X = -0.001 x 888 x 3,62 x 79 = - 910 kgm (+)

Mly = 0.001 . qu . Lx2 . X = 0.001 x 888 x 3,62 x 16 = 185kgm

Mty = -0.001 . qu . Lx2 . X = -0.001 x 888 x 3,62 x 57 = - 656 kgm (+)

Momen arah x

Mnx =

Muφ =

9100,9 = 1138 kgm

Rn =Mnb×dx2

=

11381x0,0942 = 128734

kgm2 =1,3 N/mm2 = 1,3 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×1,3350 )

= 0,0038

Asperlu = . b . dx..

Ly = 360 cm

Ly = 320 cm

Tugas Besar

= 0,0043 x 1000 x 94

= 405 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12 mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Momen arah y

Mny =

Muφ =

6560,9 = 820 kgm

Rn =

Mnb×dy2 =

8201 x 0,0822 = 121951

kgmm2 =1.2 N/mm2 = 1.2 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×1,2350 )

=

0,0036

Asperlu = . b . dy.

= 0,0043 x 1000 x 82

= 353 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12 mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

B. PELAT ATAP TYPE 2 UKURAN (4 m x 3.5 m)

40/60

35/40 25/35

40/60

Tugas Besar

Lx= 350-(35/2)-(25/2)=320 cmLy=400-2(40/2)=360 cm

persamaan momen sebagai berikut : (Iy/Ix = 1.2)(b=1000mm)Mlx nilai X =28

Mtx nilai X = 64

Mly nilai X =20

Mty nilai X = 36

Mlx = 0.001 . qu . Lx2 . X = 0.001 x 888 x 3,22 x 28 = 255kgm

Mtx = -0.001 . qu . Lx2 . X = -0.001 x 888 x 3,22 x 64 = - 582 kgm (+)

Mly = 0.001 . qu . Lx2 . X = 0.001 x 888 x 3,22 x 20 = 182 kgm

Mty = -0.001 . qu . Lx2 . X = -0.001 x 888 x 3,22 x 36 = - 328 kgm (+)

Momen arah x

Mnx =

Muφ =

5820,9 = 685 kgm

Rn =Mnb×dx2

=

6851x0,0942 = 77490

kgm2 =0,8 N/mm2 = 0,8 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×0,8350 )

= 0,0023

Asperlu = . b . dx..

= 0,0043 x 1000 x 94

= 405 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12 mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Momen arah y

Mny =

Muφ =

3280,9 = 386 kgm

Rn =

Mnb×dy2 =

386 1 x 0,0822 = 57406

kgmm2 =0,6 N/mm2 = 0,6 Mpa

Lx = 360 cm

Ly = 565 cm

Tugas Besar

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×0,6350 )

= 0,0017

Asperlu = . b . dy

= 0,0043 x 1000 x 82

= 353 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12 mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

C. PELAT LANTAI TYPE 1 UKURAN (4 m x 6 m)40/60

35/50 35/40

40/60

Ly= 600-2(35/2)=565 cmLx=400-2(40/2)=360 cm

PBI 1971 tabel 13.3.2 didapat persamaan momen sebagai berikut : (Iy/Ix

= 1,6)( b=1000mm)

Mlx nilai X = 37

Mtx nilai X = 79

Mly nilai X = 16

Mty nilai X = 57

Mlx = 0.001 . qu . Lx2 . X = 0.001 x 1609x 3,62 x 37 = 772 kgm

Mtx = -0.001 . qu . Lx2 . X = -0.001 x1609 x 3,62 x 79 = - 1648 kgm (+)

Mly = 0.001 . qu . Lx2 . X = 0.001 x 1609x 3,62 x 16 = 334 kgm

Mty = -0.001 . qu . Lx2 . X = -0.001 x 1609 x 3,62 x 57 = - 1189kgm (+)

Tugas Besar

Momen arah x

Lapangan

Mnx =

Muφ =

7720,9 = 965 kgm

Rn =Mnb×dx2

=

9651x0,0942 = 109212

kgm2 =1,1N/mm2 = 1,1 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×1,1350 )

= 0,0032

Asperlu = . b . dx..

= 0,0043 x 1000 x 94

= 405 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Tumpuan

Mnx =

Muφ =

16480,9 = 2060 kgm

Rn =Mnb×dx2

=

20601x0,0942 = 233137

kgm2 =2,3 N/mm2 = 2,3 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×2,3350 )

= 0,007

Asperlu = . b . dx..

= 0,007 x 1000 x 94

= 658 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 678 mm2)

Momen arah y

Lapangan

Mnx =

Muφ =

3340,9 = 418 kgm

Ly = 360 cm

Lx =320cm

Tugas Besar

Rn =Mnb×dx2

=

4181x0,0822 = 62281

kgm2 =0,6N/mm2 = 0,6 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×0,6350 )

= 0,0017

Asperlu = . b . dx..

= 0,0043 x 1000 x 82

= 352 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Tumpuan

Mny =

Muφ =

1189 0,9 = 1487 kgm

Rn =

Mnb×dy2 =

14871 x 0,0822 = 221314

kgmm2 =2,2 N/mm2 = 2,2 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×2,2350 )

= 0,0066

Asperlu = . b . dy

= 0,0066 x 1000 x 82

= 539 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 565 mm2)

D. PELAT LANTAI TYPE 2 UKURAN (4 m x 3.5 m)40/60

35/50 35/35

40/60

Tugas Besar

Lx= 350 - (35/2) - (25/2) =320 cmLy=400-2(40/2)=360 cm

persamaan momen sebagai berikut : (Iy/Ix = 1.2)(b=1000mm)Mlx nilai X = 23

Mtx nilai X = 64

Mly nilai X = 20

Mty nilai X = 56

Mlx = 0.001 . qu . Lx2 . X = 0.001 x 1609 x 3,22 x 23 = 378 kgm

Mtx = -0.001 . qu . Lx2 . X = -0.001 x 1609x 3,22 x 64 = - 1055kgm (+)

Mly = 0.001 . qu . Lx2 . X = 0.001 x 1609x 3,22 x 20 = 330 kgm

Mty = -0.001 . qu . Lx2 . X = -0.001 x 1609x 3,22 x 56 = - 923 kgm (+)

Momen arah x

Lapangan

Mnx =

Muφ =

3780,9 = 445 kgm

Rn =Mnb×dx2

=

4451x0,0942 = 50551

kgm2 =0.5 N/mm2 = 0.5 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×1350 )

= 0,0015

Asperlu = . b . dx..

= 0,0043 x 1000 x 94

= 405mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Tumpuan

Mnx =

Muφ =

10550,9 = 1242 kgm

Rn =Mnb×dx2

=

12421x0,0942 = 140517

kgm2 =1,4 N/mm2 = 1,4 Mpa

Tugas Besar

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×1,4350 )

= 0,0041

Asperlu = . b . dx..

= 0,0043 x 1000 x 94

= 405mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Momen arah y

Lapangan

Mnx =

Muφ =

3300,9 = 488 kgm

Rn =Mnb×dx2

=

4881x0,0822 =57715

kgm2 =0,6N/mm2 = 0,6 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×0,6350 )

= 0,0025

Asperlu = . b . dx..

= 0,0043 x 1000 x 82

= 386mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)

Tumpuan

Mny =

Muφ =

923 0,9 = 1085 kgm

Rn =

Mnb×dy2 =

10851 x 0,0822 = 161493

kgmm2 =1,6 N/mm2 = 1,6 Mpa

perlu =

1m (1−√1−2m×Rn

fy ) =

111,76 (1−√1−

2×11,76×1,6350 )

= 0,0047

Tugas Besar

Asperlu = . b . dy

= 0,0047 x 1000 x 82

= 384 mm2

Smax = 300(280/(2/3 x fy))=250 mm

Jika dipakai tulangan 12mm, As = 0,25 x 3,14 x 122 = 113 mm2

Dipasang tulangan lentur 12-250 mm (As pakai 452 mm2)