Perhitungan Pondasi Bored PileTiang PancangDaya Dukung Tiang Pancang berdasar hasil Invetigasi tanah 1. Calculation of Piles Foundation by CPTD =600 mmL = Length of pile=18 mP =Cross section perimeter of pile=1884,956 mm= 1,884956 mAp =Cross section area of pile=2827,433 cm2=0,002827 m2As=Blanket area of pile= 33,9292 m2 Soil DataCPT=200 kg/cm2 at -18 m1.Piles Bearing CapacityCalculation of End Bearing of piles from CPT dataQult=Qp + QsWhere,Qult=ultimate axial bearing capacity of pile (ton)Qp= end bearing at the pile point ton)Qs=Load carried by skin friction developed at the side of pile (ton)(caused by shearing resistance between the soil and the pile)Ap=Area of cross section of pile (m2)As=Area of blanket of pile (m2)Qp= 565486,6776 kg=565,4867 tonQs=(213-0)/6 + (379-213)/6 + (685 379)/6= 220 * (35,5 + 36,67 + 51)=24897,4 kg= 24,8974 tonQult= Qp + Qs= 392,6991 + 24,8974= 590,3841 tonSF= 2,4 (SF design 2,4 2,8)Qall=Qult/SF= 245,9934 ton2. Calculation of Piles Foundation by CPTD =600 mmL = Length of pile=12 mP =Cross section perimeter of pile=1884,956 mm= 1,884956 mAp =Cross section area of pile=2827,433 cm2=0,002827 m2As=Blanket area of pile= 22,61947 m2Soil DataCPT=200 kg/cm2 at -18 mPiles Bearing CapacityCalculation of End Bearing of piles from CPT dataQult=Qp + QsWhere,Qult=ultimate axial bearing capacity of pile (ton)Qp= end bearing at the pile point ton)Qs=Load carried by skin friction developed at the side of pile (ton)(caused by shearing resistance between the soil and the pile)Ap=Area of cross section of pile (m2)As=Area of blanket of pile (m2)Qp= 565486,6776 kg=565,4867 tonQs=(232-0)/6 + (521-232)/6= 220 * (38,6 + 48,16)=19087,2 kg= 19,0872 tonQult= Qp + Qs= 565,4867 + 19,0872= 584,5739 tonSF=2,4 (SF Design 2,4 2,8)Qall=Qult/SF= 243,5724 ton

1. PERHITUNGAN PONDASI BORE PILE

Spesifikasi teknik.Jenis tiang pancang: Bore pileUkuran: D 400 mmPanjang tiang: 14.5 mMutu bahan: K250 (fc=22.5Mpa)Vu:

Karena diameter yang digunakan 600 mm maka termasuk jenis normal Bore Pile, sehingga perhitungan beban ultimate yang didasarkan pada dya dukung tanahnya menggunakan rumus :

Pu=9*Cb*Ab+0,5*pi*d*Cs*Ls

Ket :Cb: kohesi tanah pada baseAb: luas baseD: diameter pileCs: kohesi pada shaft (selubung)Ls: panjang shaft (selubung)

Untuk mendapatkan beban yang aman, diperkenankan :

Fs= 2,5 4 tergantung kondisi tanahDkarenakan kondisi tanah cukup baik maka diambil Fs = 3Diketahui :Cs= 18,25 t/m2Cb= 82,5 t/m2

1. Base ResistanceP1= 9*Cb*Ab= 9*82,5*1/4*3.143*0,42= 93,258 ton

2. Shaft ResistanceP2=0,5*pi*d*Cs*Ls= 0,5*pi*0,4*18.25*4= 45,8878 ton

= 45,879

Penentuan jumlah Bore PileJumlah Bore Pile, Direncanakan menggunakan 4 BORE PILE

Jarak Antara Bore Pile S > 2,5 3DJarak minimal Antara Bore Ple =2,5 D = 1,0 mJarak maksimal Antara Bore Pile = 6D = 2,4 mDiambilJarak Antara Bore Pile = 1,1 mJarak Bore Pile ketepi = 0,4 m

Gambar 1 Denah penempatan bore pile

Vu = 148,72 tonMu=