PC-ITB.xls

1. 설계조건 a. Concrete Precast PC : fck = 35 MPa Ec = 8500*(fck+4)^(1/3) = 28825 MPa fcki = 24.5 MPa Eci = 8500*(fcki+4)^(1/3) = 25964 MPa Topping Slab : fckt = 24 MPa Ect = 8500*(fckt+4)^(1/3) = 25811 MPa b. 철근 휨인장용철근 : SD400 ( fy = 400 MPa) 전단보강용철근 : SD400 ( fys = 400 MPa) c. 프리스트레스긴장재 : KS D 7002 38 Fpu = 183 이상 kn fpu = Fpu/Aps1 = 183*10^3/98.71 = 1854 MPa Fpy = 156 이상 kn fpy = Fpy/Aps1 = 156*10^3/98.71 = 1580 MPa Aps1 = 98.71 mm 2 Eps = 200000 MPa 직경 ds = 12.7 mm 2. 허용응력도 - 콘크리트 a. 프리스트레스도입직후 압축연단에서최대압축응력 0.6*fcki = 0.6*24.5 = 14.70 MPa 인장연단에서최대인장응력 0.25* fcki = 0.25* 24.5 = 1.24 MPa 단순지지부재단부의최대인장응력 0.50* fcki = 0.50* 24.5 = 2.47 MPa b. 모든프리스트레스손실을허용한후에사용하중하의응력 압축연단에서최대압축응력 ( 긴장력 + 지속하중 ) 0.45*fck = 0.45*35 = 15.75 MPa (Precast Beam용 ) 0.45*fckt = 0.45*24 = 10.80 MPa (Topping Slab용 ) ( 긴장력 + 전체하중 ) 0.60*fck = 0.60*35 = 21.00 MPa (Precast Beam용 ) 0.60*fckt = 0.60*24 = 14.40 MPa (Topping Slab용 ) 압축프리스트레스가가해진인장영역내의최대인장응력 (- 일반적인경우 ) 0.63* fck = 0.63* 35 = 3.73 MPa (Precast Beam용 ) 0.63* fckt = 0.63* 24 = 3.09 MPa (Topping Slab용 ) 압축프리스트레스가가해진인장영역내의최대인장응력 (- 환산균열단면과 2개의선형으로이루어진모멘트-처짐관계를이용하여구한즉시처짐과장기처짐이규준을만족시키는경우 ) 1.0* fck = 1.0* 35 = 5.92 MPa - strand Initial jacking force Po = 0.75 *Fpu = 0.75*183 = 137.3 kn/strand MIN(0.80*Fpu, 0.94*Fpy) = 146.4 kn/strand at Release Pi = 0.90 *Po = 0.9*137.3 = 123.6 kn/strand MIN(0.74*Fpu, 0.82*Fpy) = 127.9 kn/strand Final Design Pt = 0.80 *Po = 0.8*137.3 = 109.8 kn/strand 0.5*Fpu = 91.5 kn/strand 3. Section Properties : 유효폭고려입력 * at Basic Section Ac y Ac*y D D1 Io A*D 2 A*D1 2 (mm) (mm) (mm 2 ) (mm) (mm 3 ) (mm) (mm) (mm 4 ) (mm 4 ) (mm 4 ) 350 675 236250 337.5 79734375-50.00 78.46 8970117188 150 350 52500 175 9187500 112.50 240.96 535937500 150 350 52500 175 9187500 112.50 240.96 535937500 341250 98109375 10041992188 * at Topping Slab n = Ect/Ec = 0.895 0 0 0 0 0 0.00 0 (0) 1790 90 144180 720 103809600-304.04 97321500 (1602) 485430 201918975 10139313688 bw = 350 mm bf = 1790 mm h = 765 mm hf = 90 mm hw = 0 mm * 프리캐스트보 * 합성보 ( 프리캐스트보 +Topping) Ac = 341250 mm 2 Acc = 485430 mm 2 yb = 287.50 mm y1c = 259.04 mm : 프리캐스트보상부 yt = 387.50 mm y2c = 415.96 mm : 프리캐스트보하부 I = 11961523438 mm 4 y3c = 349.04 mm : Topping 상부 St = 30868448 mm 3 y4c = 259.04 mm : Topping 하부 Sb = 41605299 mm 3 Icc = 31018188315 mm 4 Z1c = 119742852 mm 3 dp' = 92.50 mm Z2c = 74570123 mm 3 e = 195.00 mm Z3c = 88867145 mm 3 db' = 55.00 mm Z4c = 119742852 mm 3 590625000 664453125 664453125 1919531250 y 5 2 bf 4 1 bw 3 1454348291 3048240384 3048240384 7550829059 0 13328045568 20878874627 hf hw h 1/7 쪽

*at Strand * at Tensile Rebar 갯수 직경 면적 거리 면적 * 거리 Pi Pt 갯수 직경 면적 거리 면적 * 거리 (ea) (mm) Aps(mm 2 ) (mm) (mm 3 ) (kn) (kn) (ea) (mm) As(mm 2 ) (mm) (mm 3 ) 6 φ12.7 592.26 55 32574.30 741.6 658.8 4 HD16 796 55 43780.00 6 φ12.7 592.26 130 76993.80 741.6 658.8 0 0 12 1184.52 109568.10 1483.20 1317.60 4 796 43780.00 4. Load and Moment/Shear Span L = 8000 mm Ln = 7200 mm Spa = 10000 mm 전단력보정계수 MF = 1.11 저감계수 ws 하중계수 wu Ms Mu Vu R.F (kn/m) L.F (kn/m) (kn-m) (kn-m) (kn) Self Weight 8.19 1.2 9.83 53.07 63.70 39.28 합성전 : M = w*l 2 /8 Dead Load 27.36 1.2 32.83 177.29 212.74 131.19 합성전 : V = w*l/2 Topping Slab 21.60 1.2 25.92 139.97 167.96 103.58 합성전 Finish Load 29.26 1.2 35.11 189.60 227.51 140.30 합성후 Live Load 0 50.00 1.6 80.00 324.00 518.40 319.68 합성후 136.41 183.69 883.93 1190.31 734.03 5. Required Prestress Force Ms = 53.07 + 177.29 + 139.97 = 370.33 kn-m Ms1 = 189.6 + 324 = 513.60 kn-m Ft = (Ms/Sb + Ms1/Z2c - 0.63* fck) / (1/Ac + e/sb) = (370.33*10^6 / 41605299 + 513.6*10^6 / 74570123-0.63* 35) / (1/341250 + 195/41605299) * 1/10^3 = 1583 kn N = Ft/Pt = 1583/109.8 = 15 ea N = 15 ea > 12 ea NG / PC강연선보강 or 철근보강 6. 프리스트레스도입직후의프리캐스트보의응력 : Pi/Ac ± Pi*e/S ± Ms/S Ms = 53.07 kn-m END ft = Pi/Ac - Pi*e/St = 1483.2*10^3/341250-1483.2*10^3*195/30868448 = 4.35-9.37 = -5.02 MPa / 인장 ft = 5.02 MPa > 0.50* fcki = 2.47 MPa / 철근보강 / USE 3 - HD22 fb = Pi/Ac + Pi*e/Sb = 1483.2*103/341250 + 1483.2*10^3*195/41605299 = 4.35 + 6.95 = 11.30 MPa / 압축 fb = 11.3 MPa 0.6*fcki = 14.7 MPa ft = Pi/Ac - Pi*e/St + Ms/St = 1483.2*10^3/341250-1483.2*10^3*195/30868448 + 53.07*10^6 /30868448 = 4.35-9.37 + 1.72 = -3.30 MPa / 인장 ft = 3.3 MPa > 0.25* fcki = 1.24 MPa / 철근보강 : USE 2 - HD22 fb = Pi/Ac + Pi*e/Sb - Ms/Sb = 1483.2*10^3/341250 + 1483.2*10^3*195/41605299-53.07*10^6 /41605299 = 4.35 + 6.95-1.28 = 10.02 MPa / 압축 fb = 10.02 MPa 0.6*fcki = 14.7 MPa 7. 프리캐스트 PC보에 Topping Slab를타설한경우 : Pt/Ac ± Pt*e/S ± Ms/S Ms = 53.07+177.29+139.97 = 370.33 kn-m END ft = Pt/Ac - Pt*e/St = 1317.6*10^3/341250-1317.6*10^3*195/30868448 = 3.86-8.32 = -4.46 MPa / 인장 ft = 4.46 MPa > 0.63* fck = 3.73 MPa / 철근보강 : USE 2 - HD22 fb = Pt/Ac + Pt*e/Sb = 1317.6*10^3/341250 + 1317.6*10^3*195/41605299 = 3.86 + 6.18 = 10.04 MPa / 압축 fb = 10.04 MPa 0.45*fck = 15.75 MPa 2/7 쪽

ft = Pt/Ac - Pt*e/St + Ms/St = 1317.6*10^3/341250-1317.6*10^3*195/30868448 + 370.33*10^6/30868448 = 3.86-8.32 + 12 = 7.53 MPa / 압축 ft = 7.53 MPa 0.45*fck = 15.75 MPa fb = Pt/Ac + Pt*e/Sb - Ms/Sb = 1317.6*10^3/341250 + 1317.6*10^3*195/41605299-370.33*10^6 /41605299 = 3.86 + 6.18-8.9 = 1.14 MPa / 압축 fb = 1.14 MPa 0.45*fck = 15.75 MPa 8. 합성보에마감하중이작용할경우 : Pt/Ac ± Pt*e/S ± Ms/S Ms = 53.07+177.29+139.97 = 370.33 kn-m Ms1 = 189.60 kn-m ft = Pt/Ac - Pt*e/St + Ms/St + Ms1/Z1c = 1317.6*10^3/341250-1317.6*10^3*195/30868448 + 370.33*10^6/30868448 + 189.6*10^6/119742852 = 3.86-8.32 + 12 + 1.58 = 9.12 MPa / 압축 ft = 9.12 MPa 0.45*fck = 15.75 MPa fb = Pt/Ac + Pt*e/Sb - Ms/Sb - Ms1/Z2c = 1317.6*10^3/341250 + 1317.6*10^3*195/41605299-370.33*10^6/41605299-189.6*10^6 /74570123 = 3.86 + 6.18-8.9-2.54 = -1.41 MPa / 인장 fb = 1.41 MPa 0.63* fck = 3.73 MPa 9. 최종사용하중시응력 : Pt/Ac ± Pt*e/S ± Ms/S Ms = 53.07+177.29+139.97 = 370.33 kn-m Ms1 = 189.6 + 324 = 513.60 kn-m ft = Pt/Ac - Pt*e/St + Ms/St + Ms1/Z1c = 1317.6*10^3/341250-1317.6*10^3*195/30868448 + 370.33*10^6/30868448 + 513.6*10^6/119742852 = 3.86-8.32 + 12 + 4.29 = 11.82 MPa / 압축 ft = 11.82 MPa 0.60*fck = 21 MPa fb = Pt/Ac + Pt*e/Sb - Ms/Sb - Ms1/Z2c = 1317.6*10^3/341250 + 1317.6*10^3*195/41605299-370.33*10^6/41605299-513.6*10^6 /74570123 = 3.86 + 6.18-8.9-6.89 = -5.75 MPa / 인장 (1) fb = 5.75 MPa > 0.63* fck = 3.73 MPa NG (2) fb = 5.75 MPa 1.0* fck = 5.92 MPa ( 환산균열단면과 2개의선형으로이루어진모멘트-처짐관계를이용하여구한처짐검토 ) 10. 슬래브상하단의응력 : Ms/S Ms = 189.6 + 324 = 513.6 kn-m ft = n*ms/z3c = 0.895*513.6*10^6 /88867145 = 5.17 MPa / 압축 ft = 5.17 MPa 0.60*fckt = 14.4 MPa fb = n*ms/z4c = 0.895*513.6*10^6/119742852 = 3.84 MPa / 압축 fb = 3.84 MPa 0.60*fckt = 14.4 MPa 11. 탈형시검토 Lifting 위치 x = Ln/ 10 = 7200/10 = 720 mm Lifting ws = 8.19 kn/m SF = 1.5 M1 = -ws*x²/2 * SF = -8.19*(720/10^3)²/2 * 1.5 = -3.18 kn-m x M1 x M1 M2 = (ws*ln²/8 - ws*ln/2*x) * SF = (8.19*(7200/10^3)²/8-8.19*(7200/10^3)/2*(720/10^3))*1.5 = 47.76 kn-m M1 위치 M2 ft = Pi/Ac - Pi*e/St + M1/St = 1483.2*10^3/341250-1483.2*10^3*195/30868448 +( -3.18)*10^6 /30868448 = 4.35-9.37 + (-0.1) = -5.13 MPa / 인장 ft = 5.13 MPa > 0.63* fcki = 3.12 MPa / 철근보강 : USE 3 - HD22 fb = Pi/Ac + Pi*e/Sb - M1/Sb = 1483.2*10^3/341250 + 1483.2*10^3*195/41605299 - (-3.180*10^6 /41605299 = 4.35 + 6.95 - (-0.08) = 11.37 MPa / 압축 fb = 11.37 MPa 0.6*fcki = 14.7 MPa 3/7 쪽

M2 위치 ft = Pi/Ac - Pi*e/St + M2/St = 1483.2*10^3/341250-1483.2*10^3*195/30868448 + 47.76*10^6 /30868448 = 4.35-9.37 + 1.55 = -3.48 MPa / 인장 ft = 3.48 MPa > 0.63* fcki = 3.12 MPa / 철근보강 : USE 2 - HD22 fb = Pi/Ac + Pi*e/Sb - M2/Sb = 1483.2*10^3/341250 + 1483.2*10^3*195/41605299-47.76*10^6 /41605299 = 4.35 + 6.95-1.15 = 10.15 MPa / 압축 fb = 10.15 MPa 0.6*fcki = 14.7 MPa 12. Check Ultimate Strength φ = 0.85 dp = h - dp' = 765-92.5 = 672.5 mm db = h - db' = 765-55 = 710.0 mm ρp = Aps/(bf*dp) = 1184.52/(1790*672.5) = 0.00098 ρ = As/(bf*db) = 796/(1790*710) = 0.00063 fpy/fpu = 1580/1854 = 0.852 0.85 γp = 0.4 β1 = 0.85 fps = fpu*[1 - (γp/β1)*(ρp*(fpu/fckt) + db/dp*ρ*fy/fckt)] = 1854*[1 - (0.4/0.85)*(0.00098*(1854/24) + 710/672.5*0.00063*400/24)] = 1778 MPa a' = (Aps*fps + As*fy) / (0.85*fckt*bf) = (1184.52*1778 + 796*400) / (0.85*24*1790) = 66.39 mm hf = 90mm / 장방형보 φmn = φ*(aps*fps*(dp-a'/2) + As*fy*(db-a'/2)) = 0.85*(1184.52*1778*(672.5-66.39/2) + 796*400*(710-66.39/2)) /10^6 = 1327.63 kn-m φmn = 1327.63 kn-m Mu = 1190.31 kn-m 13. 철근비검토 gp = Aps/(bf*dp)*fps/fckt + db/dp*as/(bf*db)*fy/fckt = 1184.52/(1790*672.5)*1778/24 + 710/672.5*796/(1790*710)*400/24 = 0.084 gp = 0.084 0.36*β1 = 0.36*0.85 = 0.306 * 단면의인장지배여부확인 c/dp = (a'/β1) / dp = (66.39/0.85) / 672.5 = 0.116 c/dp = 0.116 < 0.375 / 인장지배 14. 휨균열모멘트검토 fr = 0.63* fck = 0.63* 35 = 3.73 MPa Ms = 53.07 + 177.29 + 139.97 = 370.33 kn-m Mcr1 = (fr + Pt/Ac + Pt*e/Sb - Ms/Sb )*Z2c = (3.73 + 1317.6*10^3/341250 + 1317.6*10^3*195/41605299-370.33*10^6/41605299)*74570123*1/10^6 = 362.82 kn-m Mcr = Ms + Mcr1 = 370.33 + (362.82) = 733.15 kn-m φmn/mcr = 1327.63/733.15 = 1.81 1.20 15. Check Deflection a. Instantaneous Camber Δ = Pi*e*Ln² / (8*Eci*I) = 1483.2*10^3*195*7200² / (8*25964*11961523438) = 6.035 mm b. 부재자중에의한처짐 Δ = 5*ws*Ln⁴ / (384*Eci*I) = 5*8.19*7200⁴ / (384*25964*11961523438) = 0.923 mm c. Dead Load에의한처짐 Δ = 5*ws*Ln⁴ / (384*Ec*I) = 5*27.36*7200⁴ / (384*28825*11961523438) = 2.777 mm d. Topping Slab에의한처짐 Δ = 5*ws*Ln⁴ / (384*Ec*I) = 5*21.6*7200⁴ / (384*28825*11961523438) = 2.192 mm e. Finish Load에의한처짐 Δ = 5*ws*Ln⁴ / (384*Ec*Icc) = 5*29.26*7200⁴ / (384*28825*31018188315) = 1.145 mm 4/7 쪽

f. Live Load에의한처짐 Δ = 5*(1-RF)*ws*Ln⁴ / (384*Ec*Ie) = 5*(1-0)*50*7200⁴ / (384*28825*7458173430.97498) = 8.138 mm np = Eps/Ec = 200000 / 28825 = 6.94 ML = 324.00 kn-m Aps = 1184.52 mm² bf = 1602.00 mm dp = 672.5 mm ρp = Aps / (bf*dp) = 1184.52 / (1602*672.5) = 0.00110 Icr = np*aps*dp²*(1-1.6* (np*ρp)) = 6.94*1184.52*672.5²*(1-1.6* (6.94*0.0011)) = 3198067970 mm⁴ Ig = Icc = 31018188315 mm⁴ Ie = (Mcr/Ma)³ * Ig + (1 - (Mcr/Ma)³)*Icr = 0.535³ * 31018188315 + (1-0.535³)*3198067970 = 7458173431 mm⁴ Mcr/Ma = 1- (ftl - fr)/fl = 1 - (5.75-3.73)/4.34 = 0.535 ftl = 5.75 MPa fr = 0.63* fck = 0.63* 35 = 3.73 MPa fl = ML/Z2c = 324*10^6/74570123 = 4.34 MPa g. Determine Long term Effects of Creep (from Fig 4-6-3, PCI HANDBO) * Release * at Erection * Final Condition Δi(mm) C.F Δ(mm) Δi(mm) C.F Δ(mm) Δi(mm) C.F Δ(mm) -6.035 1.00-6.035-6.035 1.80-10.863-6.035 2.20-13.277 0.923 1.00 0.923 0.923 1.85 1.708 0.923 2.40 2.215-5.112 2.777 1.00 2.777 2.777 2.30 6.387 2.192 1.00 2.192 2.192 2.30 5.042 1.145 1.00 1.145 1.145 3.00 3.435-3.041 3.802 Deflection(LL) 8.138 11.940 ΔTL = (3.802-(-3.041)) + 8.138 = 14.981 mm ( 모든지속하중에의한장기처짐 + 추가적인활하중에의한순간처짐 ) h. Check Δ allowable Ln/360 = 7200/360 = 20.00 mm ΔLL = 8.138 mm Ln/480 = 7200/480 = 15.00 mm ΔTL = 14.981 mm 16. Check Shear φ = 0.75 0 1/12*L 50*ds 2/12*L 3/12*L 4/12*L 5/12*L 6/12*L 위험단면 거리 0.00 600.00 635.00 1200.00 1800.00 2400.00 3000.00 3600.00 0.00 (mm) Vu 734.03 611.69 604.55 489.35 367.01 244.68 122.34 0.00 734.03 (kn) Mu 0.00 403.71 425.00 734.03 990.93 1174.44 1284.54 1321.25 0.00 (kn-m) dp 672.50 672.50 672.50 672.50 672.50 672.50 672.50 672.50 672.50 (mm) d = MAX(0.8*h, dp) 672.50 672.50 672.50 672.50 672.50 672.50 672.50 672.50 672.50 (mm) Vu*dp/Mu 1.00 1.00 0.96 0.45 0.25 0.14 0.06 0.00 1.00 Prestress force P 0 1244.98 1317.60 1317.60 1317.60 1317.60 1317.60 1317.60 0.00 (kn) fpc = P/Ac 0.00 3.65 3.86 3.86 3.86 3.86 3.86 3.86 0.00 (MPa) Vp 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 (kn) φvc1 917.22 917.22 882.62 441.47 268.47 173.32 104.12 52.22 917.22 (kn) φvc2 302.87 496.17 507.29 507.29 507.29 507.29 507.29 507.29 302.87 (kn) φvc3 174.06 174.06 174.06 174.06 174.06 174.06 174.06 174.06 174.06 (kn) φvc4 435.16 435.16 435.16 435.16 435.16 435.16 435.16 435.16 435.16 (kn) φvc 302.87 435.16 435.16 435.16 268.47 174.06 174.06 174.06 302.87 (kn) φvc /2 151.44 217.58 217.58 217.58 134.24 87.03 87.03 87.03 151.44 (kn) φvs 431.16 176.53 169.39 54.19 98.54 70.62 0.00 0.00 431.16 (kn) ( 최소 ) ( 불필요 ) φ*2/3* fck*bw*d 696.25 696.25 696.25 696.25 696.25 696.25 696.25 (kn) () () () () () () () φ*1/3* fck*bw*d 348.12 348.12 348.12 348.12 348.12 348.12 348.12 (kn) ( 간격 /2) ( 간격 /2) leg 2 2 2 2 2 2 2 2 2 leg stirrup HD13 HD13 HD13 HD13 HD13 HD13 HD13 HD13 HD13 S1 573 573 573 573 573 573 573 573 573 (mm) S2 785 785 785 785 785 785 785 785 785 (mm) S3 829 829 829 829 829 829 829 829 829 (mm) S4 1795 1795 1795 1795 1795 1795 1795 1795 1795 (mm) S5 119 290 303 946 520 726 119 (mm) S = MIN(S1,S2,S3,S4,S5) 119 290 303 573 520 573 573 573 119 (mm) USE @100 @150 @150 @150 @150 @200 @200 @200 @100 (mm) 5/7 쪽

800.00 700.00 600.00 전단보강여부검토 (Half Span) Vu(kN) φvc(kn) 위험단면 φvc/2(kn) Vu(kN) or ΦVc(kN) 500.00 400.00 300.00 200.00 100.00 0.00 0.00 500.00 1000.00 1500.00 2000.00 2500.00 3000.00 3500.00 4000.00 거리 (mm) a. Use 2leg- HD13 (Av = 254.00 mm 2 ) Smax1 = MIN(3/4*h, 600)/2 = MIN(3/4*765, 600)/2 = 286 mm Smax2 = Av*fys / (0.0625* fck*bw) = 254*400 / (0.0625* 35*350) = 785 mm Smax3 = Av*fys / (0.35*bw) = 254*400/(0.35*350) = 829 mm Smax4 = Av / ((Aps/80)*(fpu/fys)*(1/d) * (d/bw)) = 254 / ((1184.52/80)*(1854/400)*(1/672.5) * (672.5/350)) = 1795 mm Smax = MIN(Smax1, Smax2, Smax3, Smax4) = MIN( 286, 785, 829, 829) = 286 mm b. 콘크리트전단강도 dp = 672.50 mm d = MAX(dp, 0.8*h) = MAX(672.5, 0.8*765) = 672.50 mm 위험단면 CS = 0.00 mm Vu = MF*wu*Ln/2 - MF*wu*CS = 1.11*183.69*(7200/10^3)/2-1.11*183.69*(0/10^3) = 734.03 kn Mu = MF*wu*CS*(L-CS) / 2 = 1.11*183.69*(0/10^3)*((7200/10^3)-(0/10^3))/2 = 0.00 kn-m Vu/Mu*dp = MIN(734.03*(672.5/1000) / 0, 1.0) = MIN(, 1.0) = 1.00 전달길이 50*ds = 50*12.7 = 635.00 mm 프리스트레스힘 P = 0.00 kn fpc = P / Ac = 0*10^3/341250 = 0.00 MPa Vp = P*slope = 0*(672.5-672.5)/(3600-0) = 0.00 kn φvc1 = φ*(0.05* fck + 4.9*Vu/Mu*dp)*bw*d = 0.75*(0.05* 35 + 4.9*1)*350*672.5/10^3 = 917.22 kn φvc2 = φ*((0.29* fck + 0.3*fpc)*bw*d + Vp) = 0.75*(0.29* 35 + 0.3*0)* 350*672.5/10^3 + 0) = 302.87 kn φvc3 = φ*1/6* fck*bw*d = 0.75 * 1/6 * 35*350*672.5/10^3 = 174.06 kn φvc4 = φ*5/12* fck*bw*d = 0.75*5/12* 35*350*672.5/10^3 = 435.16 kn φvc = MIN( MAX( MIN(Vc1, Vc2), Vc3), Vc4 ) = MIN( MAX( MIN( 917.22, 302.87), 174.06), 435.16) = 302.87 kn c. 전단보강근의전단강도 φvs = Vu - φ*vc = 734.03-302.87 = 431.16 kn d. 보단면적정성검토 φ*2/3* fck*bw*d = 0.75*2/3 * 35*350*672.5/10^3 = 696.25 kn φvs = 431.16 kn φ*2/3* fck*bw*d = 696.25 kn e. 전단보강근검토 φ*1/3* fck*bw*d = 0.75*1/3 * 35*350*672.5/10^3 = 348.12 kn φvs = 431.16 kn > φ*1/3* fck*bw*d = 348.12 kn ( 간격 /2) f. 전단보강근간격 S = MIN(φ*Av*fys*d/(φ*Vs), Smax) = MIN(0.75*254*400*672.5/(431.16*10^3), 286) = 119 mm 6/7 쪽

17. 수평전단설계 (2) τnh = 0.56 MPa 1). 최소전단연결재가없으면서접촉면이청결하고부유물이없으며접촉면을의도적으로거칠게만든경우 ----------- τnh = 0.56 MPa 2). 최소전단연결재가있으면서접촉면이청결하고부유물이없으며접촉면을의도적으로거칠게만들어지지않은경우 ----------- τnh = 0.56 MPa 3). 최소전단연결재가있으면서접촉면이청결하고부유물이없으며접촉면을의도적으로거칠게만든경우 ----------- τnh = 3.5 MPa C1 = 0.85*fckt*bf*hf = 0.85*24*1790*90/10^3 = 3286.4 kn C2 = 0.85*fckt*bw*hw = 0.85*24*350*0/10^3 = 0.0 kn C = C1 + C2 = 3286.4 + 0 = 3286.40 kn T1 = Aps*fps = 1184.52*1778/10^3 = 2106.08 kn T2 = As*fy = 796*400/10^3 = 318.40 kn T = T1 + T2 = 2106.08 + 318.4 = 2424.48 kn Fh = MIN(C, T) = MIN( 3286.4, 2424.48 ) = 2424.48 kn bv = 350 mm Lvh = 3600.00 mm λ = 1.0 φvnh = φ*τnh*bv*lvh = 0.75*0.56*350*3600/1000 = 529.20 kn Fh/φVnh = 2424.48 / 529.2 = 4.581 > 1.00 NG - 최소전단연결재 2leg- HD13 @200 (Av = 254.00 mm²) Smax1 = Av*fys/(0.0625* fck*bw) = 254*400/(0.0625* 35*350) = 785 mm Smax2 = Av*fys/(0.35*Bw) = 254*400/(0.35*350) = 829 mm Smax3 = MIN(hf*4, 600) = MIN(90*4, 600) = 360 mm Smax = MIN(Smax1, Smax2, Smax3) = MIN(785, 829, 360) = 360 mm S/Smax = 200 / 360 = 0.556 1.00 ( 조건만족 ) φ*3.5*bv*lvh = 0.75*3.5*350*3600/1000 = 3307.50 kn Fh/(φ*3.5*bv*Lvh) = 2424.48 / 3307.5 = 0.733 1.00 Fh = φ*(1.8+ 0.6*ρv*fys)*λ*bv*Lvh 로부터 ρv를구하여 Av,req를구한다. Av,req = (Fh/(φ*λ*bv*Lvh) - 1.8) / (0.6*fys)*bv*Lvh = (2424.48*10^3 / (0.75*1*350*3600) - 1.8) / (0.6*400) * 350*3600 = 4019.33 mm²/m S,req = MIN(Lvh*Av/Av,req, Smax ) = MIN(3600*254 / 4019.33, 360) = MIN( 227, 360) = 227 mm S/S,req = 200 / 227 = 0.881 1.00 7/7 쪽