Initial Desain Balok Prategang Aplikasi Pada Girder JembatanSumber : Berdasarkan file karya Ir. M. Noer Ilham, MTDATA JEMBATAN Spesific Gravity Uraian NotasiDimensi Jenis Bahan Berat (kN /m^3)Panjang balok prategang L45mBeton prategang Wc25.50Jarak antara balok prategang s1.8mBeton bertulangWc'25.00Tebal plat lantai jembatan h00.2mBeton Wc"24.00Tebal lapisan aspal + overlayha0.1mAspal W aspal22.00Tinggi genangan air hujan th0.05mAir hujan W air9.80Dimensi Balok Prestress Kode Lebar (m)KodeTebal (m)b10.6h10.07b20.8h20.13b30.3h30.12b40.2h41.65b50.25h50.25b60.75h60.25 h2.101. BETONSimbolPersamaan Nilai Satuan Mutu beton girder prestress K600Kuat tekan beton fc'0.83*K/1049.8MpaModul elastik betonEc4700*(fc')^1/233167.4840770294MpaAngka Poisson0.15Modulus Geser GEc / [2*(1+ (angka poisson))]MpaKoefisien muai panjang untuk beton 0.0001/ CKuat tekan beton pada keadaan awal (saat transfer)fci'0.80 * f'c39.84MpaTegangan ijin beton saat penarikan Tegangan ijin tekan 0.60 * fci'23.904Mpa Tegangan ijin tarik 0.50 * (fci')^1/23.1559467676MpaTegangan ijin beton pada keadaan akhir Tegangan ijin tekan 0.45 * fci'17.928Mpa Tegangan ijin tarik 0.45 * (fci')^1/22.8403520909Mpa

Mutu beton plat lantai jembatan K300Kuat tekan betonfc'0.83*K/1024.9MpaModulus elastik betonEc4700*(fc')^1/22E+04Mpa2. BAJA PRATEGANG DATA STRANDS CABLE - STANDAR VSL Jenis strandTegangan leleh strand fpy 1580MPaKuat tarik strandfpu1860MPaDiameter nominal strand12.7mmLuas tampang nominal satu strandAst98.7mm^2Beban putus minimal satu strandPbs187.32kNJumlah kawat untaian (strands cable)19/tendonDiameter selubung ideal84mmLuas tampang strand1875.3mm^2Beban putus satu tendonPb13559.1kNModulus elastis strandEs193000MPaTpe dongkrak VSL 193. BAJA TULANGAN Untuk baja tulangan deform D > 12 mmU - 32Kuat leleh baja fy = U*10.. MpaUntuk baja tulangan polos 12 mmU - 24Kuat leleh baja fy = U*10.. MpaA. PENENTUAN LEBAR EFEKTIF PLAT JEMBATANLebar efektif plat (Be) diambil nilai terkecil dari :

L/4 =11.25ms =1.8m12 * ho =2.4mDiambil lebar efektif plat lantai Be =1.8mKuat tekan beton platFc' = 0.83 * K (plat) =24.9MPaKuat tekan beton balok fc' (balok) = 0.83 * K (balok) =49.8MPaModulus elastik plat beton E plat = 4700 * (fc')^1/233167.4840770294MPaModulus elastik balok beton prategang E balok = 0.043 * (Wc)^1.5 * (fc' balok)^0.5 =39074.4971340003MPaNilai perbandingan modulus elastik plat dan balok n = E plat / E balok = 0.848826895Lebar pengganti beton plat lantai jembatan B eff = n * Be =1.5278884111m

Momen Inersia2. SECTION PROPERTIES BALOK PRATEGANGNo DIMENSI LUAS TAMPANG A (m^2) JARAK THDP ALAS, y (m)STATIS MOMEN [ A*y (m^3) INERSIA MOMEN [A*y^2] (m^4) INERSIA MOMEN, Io (m^4) Lebar, b (m)Tinggi, h (m)10.640.070.044802.070.09273600.191963520.0000220.80.130.104001.970.20488000.40361360.0001530.30.120.036001.860.06696000.12454560.0000340.21.650.330001.080.35640000.3849120.0748750.250.250.062500.330.02062500.006806250.0002260.70.250.175000.130.02275000.00295750.00091Total0.75230.7643511.114798470.0761907822Tinggi total balok prategangh=2.1mho0.20mLuas penampang balok prategangA=0.7523m^2B eff1.53mLuas titik beratYbA*y / A1.0160188754mYa = h - Yb1.084mMomen inersia terhadap alas balok Ib = A*y / Io1.1909892522m^4Momen inersia terhadap titik berat balokIx = Ib - A * Yb^20.4143942088m^4Tahanan momen sisi atasWa = Ix / Ya0.3822891371 m^3Tahanan momen sisi bawah Wb = Ix / Yb0.4078607384 m^3

3. SECTION PROPERTIES BALOK COMPOSITE ( BALOK PRATEGANG + PLAT)No DIMENSI LUAS TAMPANG JARAK THDP ALAS, y (m)STATIS MOMEN [ A*y] (m^3) INERSIA MOMEN [A*y^2] (m^3) INERSIA MOMEN, Io (m^4) Lebar, b (m)Tinggi, h (m)11.180.20.236002.20.51920001.142240.0007920.640.070.044802.070.09273600.191963520.0000230.80.130.104001.970.20488000.40361360.0001540.30.120.036001.860.06696000.12454560.0000350.21.650.330001.080.35640000.3849120.0748760.250.250.062500.330.02062500.006806250.0002270.70.250.175000.130.02275000.00295750.00091Total0.988301.283552.257040.07698Tinggi total balok compositeh=2.3mho0.20mLuas penampang balok compositeA=0.9883m^2B eff1.53mLuas titik beratYbA*y / A1.2987463321mYa = h - Yb1.0012536679m

Momen inersia terhadap alas balok Ibc = Ac * y^2 + Ic02.33402m^4Momen inersia terhadap titik berat balok compositIxc = Ibc - Ac *Ybc^20.66701m^4Tahanan momen sisi atas platWac = Ixc / Yac0.6661736051 m^3Tahanan momen sisi atas balok W'ac = Ixc / (Yac - h0)0.8324564271 m^3Tahanan momen sisi bawah balokWbc = Ixc / Ybc0.5135789408m^3