Enter company name Project: PROJECT ???? Subject: CONCRETE TECH 48" BULB-TEE Project # 06/15/18 Date: PSGSimple YP Engineer: Checker: Page: Date: Copyright © 2007 Preliminary Design Of Prestressed Precast Concrete Bridge Girder With Cast-In-Place Concrete Composite Deck ( Design Code: AASHTO LRFD 4th Edition, 2007 ) Materials Concete Properties Compressive strength, Modulus of Elasticity, ksi ksi f'c = Ec = Girder @ 28 days 4,815 f'ci = Eci = Girder @ transfer 4,458 f'cd = 4.5 Ecd = Concrete unit weight, c = 0.155 kip/ft³ Deck @ 28 days Prestressing Steel Properties Strand type = Tensile strength, fs = Modulus of elasticity, Ep = Strand diameter = Single strand area = 3,861 Low relaxation 270 ksi 28,500 ksi 0.5 in 0.153 in² Geometry General Clear span or brg-to-brg, L = Girder spacing, S = Effective deck thickness, teff = Sacrificial deck depth = Effective deck width, beff = Average annual relative humidity, H = Conc pad thickness above top flange = Ec = 1820√f'c 72 7.5 0.5 84 80 2.5 ft ft in in (additive to teff) Leave blank if agree with bef value in -> overwrite final = % in (used for concrete weight calculations only) sacrificial deck depth Precast girder properties Girder label = Depth, Hg Area, Ag Moment Inertia, Ig Centroid from bottom, yb W42G = 42.0 in = 374.0 in² = 76,437 in4 = 18.89 in Top flange width = 15.00 in 84 in haunch beff teff temporary strands harped strands Hg straight strands Composite girder properties n = Ec/Ecd = Ac = 1.25 845 in² Ic = ybc = 226,038 in4 33.73 in Ac = Ag+teffbeff/n Ic = Ig+Ag(yb-ybc)²+beffteff³/12/n+beffteff(Hg+teff/2-ybc)²/n ybc = (Agyb + teffbeff(Hg+teff/2)/n)/Ac Loads Noncomposite Dead Loads, k/ft Girder, wg = 0.403 Slab Haunch Extra Slab Total wD = 0.727 = 0.04036 = 0.1 = 1.269 k/ft Composite Dead Loads, k/ft Overlay = 0.13 Barrier = 0.3 Utilities = 0.08 Diaphragms, etc = 0.05 Total wCD = 0.560 k/ft Moment due to all non-composite loads @ 1/2 span MD = wDL²/8 = 823 k-ft Moment due to girder weight @ strands harp point (X=24 ft) M = wgX(L-X)/2 = 232 k-ft Moment due to composite loads @ 1/2 span MCD = WCDL²/8 = 363 k-ft Overwrite MCD = k-ft Live Loads (HL93) Moment due to a lane of HL93 , ML1 = Overwrite ML1 = 1,773 k-ft Comment: k-ft Lane distribution factor, DF = 0.647 Live load moment per girder, M(L+I) = 1,148 k-ft Formula for ML1 =(0.64)L²/8+1.33[32.0(L/2-2.333)(L-9.333) + 8.0(L/2-16.333)(L/2+2.333)]/L file:///home/webmaster/mojo/converter/data/uploads/vy3b8181hmifhs7c/o_1cg0mupo01i7h1gci173k1uc715963i/tmp.xls Page of Enter company name Project: PROJECT ???? Subject: CONCRETE TECH 48" BULB-TEE YP Engineer: 06/15/18 Date: PSGSimple Project # Checker: Page: Date: Copyright © 2007 Prestressing Stress in prestressing strands prior to transfer, fpi = Permanent strands Strands layout @ midspan 270 x str No strands C.G from bottom, in 2.00 str 4.00 str str 0 6.00 8.00 harped Temp strands 12 3.00 40.00 Prestressing Parameters Prestressing losses Units ksi 0.75 = 202.5 ksi (31 kip per strand) Harp point location from the girder end: 0.333 x 72 ft = For prestressing losses see calculations on the right @ Transfer 24.5 @ Final 49.7 Prestressing after losses ksi 178.0 152.8 Prestressing force in one strand kip 27.2 23.4 31 6.58 12.31 -844 -866 28 3.00 15.89 -655 -867 Stresses Bottom ksi 2.440 0.650 2.056 -4.322 Top ksi -2.985 -0.159 -0.504 1.395 Number of strands Strands c.g from girder soffit, ys Eccentricity to girder centroid, em Prestressing force, Pps Prestressing moment, Mps = Ppsem in in kip kip-ft 23.98 ft Stress Check ("+" for tension, "-" for compression) Section @ 1/2 span Service load after all losses Noncomposite dead loads Composite permanent loads Composite Live Loads Final prestressing force P kip 0 -655 M kip-ft 823 363 1,148 -867 Service III combination (D+0.8L+P) 0.412 0.19 √f'c = Allowable teinsile stress 0.503 OK Service I (D+L+P) -2.253 0.45 f'c = Allowable compressive stress Section 23.98 ft from girder end Immediately after transfer Girder weight Prestress Total Allowable compressive stress P kip -844 M kip-ft 232 -866 0.6 f'ci = Allowable tensile stress 0.0948√f'ci