Contoh Perhitungan Pondasi TC ( Tower Crane )

Contoh Perhitungan Pondasi TC ( Tower Crane )

Berikut ini contoh perhitungan pondasi TC ( Tower Crane )

Data perhitungan tower Crane:

- Type TC = FO-23 B (HUH 106 M)

- Counter Weight = 16.0 ton

- Max Angkut = 8.0 ton

- Jib Length = 52.0 m

- Pjg Counter Weight = 13.0 m

- Jarak Max Angkut = 12.2 m

- Max Beban Ujung = 1.8 ton

- Lebar Section TC = 1.9 m

- Mutu Beton f’c = 29.1 mpa K = 350 kg/cm2

- Mutu Baja fy = 400.0 mpa

- Diameter Tulangan = 25.0 mm

- Lebar Pondasi ( B ) = 5.0 m

- Panjang Pondasi ( L ) = 5.0 m

- Tinggi Pondasi ( d ) = 1.4 m

BEBAN TOWER CRANE ( BROSUR TC )

a. Kondisi TC Dalam Keadaan Operasi ( Crane In Operation )

- Momen Yang Bekerja ( M ) = 1730 KN.m

- Gaya Horisontal ( H ) = 32 KN

- Gaya Axial ( V ) = 636 KN

- Momen Torsi ( MT ) = 0 KN.m

b. Kondisi TC Dalam Keadaan Tak Operasi ( Crane Out Operation )

- Momen Yang Bekerja ( M ) = 0 KN.m

- Gaya Horisontal ( H ) = 0 KN

- Gaya Axial ( V ) = 0 KN

- Momen Torsi ( MT ) = 0 KN.m

PERENCANAAN PONDASI TC

a. direncanakan ukuran poer pondasi ssb : 5.0 x 5.0 x 1.4 m

( d = kedalaman)

* lihat panjang minimum angkur tower crane

( B = lebar ) 5.0

( L = panjang )

Berat Pondasi Tower Crane : = 5.0 x 5.0 x 1.4 x 2400 kg/m3

= 81000 kg

= 81 KN

Total Gaya Axial Yang Bekerja : = 636 + 81

= 717 KN

Perhitungan pondasi TC

PERHITUNGAN PONDASI :

a. Kontrol Terhadap Guling

∑M = 0

V M + V.L/2 + H.d/2 = 0

M L = (( M + H.d/2 ) * 2)/ V

H 1.35 L = ({ 1730 + 21.6 } * 2)/ 717

= 3503.2 /717

= 4.89 m

Jadi Ukuran Pondasi Tower Crane = 4.89 x 4.89 x 1.4 M

( B = lebar ) 4.9

4.9 ( L = panjang )

1.4 ( d = kedalaman)

b. Kontrol Terhadap Geser

- Momen Yang Bekerja ( M ) = 1730 KN.m

- Gaya Horisontal ( H ) = 32 KN

- Gaya Axial ( V ) = 717 KN

- Momen Torsi ( MT ) = 0 KN.m

ΦVc = ( 1 + 1/βc ) * 1/6 *√f’c *bo*d —-( SKSNI T – 15 1991 Ayat 3.4.26 )

dimana :

βc = rasio sisi pendek dengan panjang = 1

bo = 2 ( hk + d ) + 2 ( bk + d )

= 2 ( 1.9 + 1.4 ) *2 = 13.08

hk / bk = lebar section/badan TC

sehingga :

ΦVc = 3172439.336 N

= 3172.439336 KN > 717 KN ………… OK OKE!!

c. Perhitungan Tulangan Poer

Mu lentur = 1730 KN = 1730000 kg

Rn = Mu / (0.8*b*d² )

= 1186.556927 KN / m2

= 0.001186557 Kg / mm2

m = fy / ( 0.85*f’c)

= 16.19925078

ρ perlu = 1/m ( 1 – √(1-(2*m*Rn)/fy))

= 1.1865E-05

ρ min = 1,4 / fy

= 0.0035 > ρ perlu ………………… Dipakai ρ min!!

As perlu = ρ * b * d

= 0.0035 * b*d

= 0.023085941 m2

= 23085.94142 mm2

Dipakai Tulangan Diameter = 25 mm

As Terpasang = 490.625 mm2/btg

Jumlah (b ) = 47.05414812

≈ 47 bh

Jarak Tulangan = 0.103835979 m

= 103.8359788 mm

≈ 104 mm

Jadi Tulangan Pondasi Tower Crane : ————-> D 25 – 104

d. Perhitungan Tulangan Puntir

Mu Puntir = 0 KN = 0 kg

Rn = Mu / (0.8*b*d² )

= 0 KN / m2

= 0 Kg / mm2

m = fy / ( 0.85*f’c)

= 16.19925078

ρ perlu = 1/m ( 1 – √(1-(2*m*Rn)/fy))

= 0

ρ min = 1,4 / fy

= 0.0035 > ρ perlu ………………… Dipakai ρ min!!

As perlu = ρ * b * d

= 0.0035 * b*d

= 0.023085941 m2

= 23085.94142 mm2

Dipakai Tulangan Diameter = 25 mm

As Terpasang = 490.625 mm2/btg

Jumlah (b ) = 47.05414812

≈ 47 bh

Jarak Tulangan = 0.103835979 m

= 103.8359788 mm

≈ 104 mm

Jadi Tulangan Pondasi Tower Crane : ————-> D 25 – 104

Gambar Penulangan Pondasi TC



Demikian contoh perhitungan pondasi TC, Semoga bermanfaat

Sumber: http://www.ilmusipil.com