Download - Girder Design

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B. DESIGN FOOTING GIRDERFRef. Code : NSCP C101-01Mark : FG1

D.EndCenterC. EndCONSTANT VALUES ;4-D204-D204-D20cc =40.00mm: concrete coverf'c =24.00N/mm: compressive strength - concretefyl =414.00N/mm: yield strength in steel - bending600hfyv =275.00N/mm: yield strength in steel - shear =0.90,0.75, 0.75: reduction factor for bending/shear/torsionq =45o: torsional angle400 brmax =0.0186: max. steel ratio4-D204-D204-D20rmin =0.0034: min. steel ratioD10@150D10@200D10@150FORMULAS ; A. MAXIMUM ULTIMATE DESIGN FORCESMu = f'c b d w (1-0.59w): eq. for singly-reinforced memberLocationMoment (Mu)ShearTorsionAxialfVc =0.75 x 0.166 (f'c) b d: shear cap. of unreinforced concreteTopBottomVuTuPuVs =(Vd - fVc ) / f: shear cap. of steel(kN-m)(kN-m)(kN)(kN-m)(kN)Av/ s =Vs / (fyv d): shear reinforcementd.end 122.2893.88104.1181.5967.33At / s =Tu / (2 f Ao fyv cot q): torsion reinforcementcenter23.9494.7866.7381.59Tcr =4 f (fc')1/2(Acp2 / Pcp): threshold torsiond.end122.2893.88104.1181.59Acp, Pcp =(bx h) , (2b + 2h): gross area , gross perimeter of section(please refer to summary of girder stresses for the actual staad forces).Al =(At/s)Ph (fyv / fyl)cot2q: add. longitudinal steel due to torsionAlmin =0.415 (fc')1/2 Acp / fyl - (At/s)Ph fyv / fylB. FLEXURE DESIGN RESULTS : (ACI sec.8.4, sec.10.5, sec.21.12.4.1)LocationTop Bar (*plus Torsional Longitudinal Steel, if req'd.)Bottom Bar (*plus Torsional Longitudinal Steel, if req'd.)r*As = r bdFurnishedRemarksr*As = r bdFurnishedRemarks(w f'c/fy)(mm)qtydia.Asprov(w f'c/fy)(mm)qtydia.AsprovFormulas ;d.end 0.0033915.284"-20"01256.64Ok0.0025915.284"-20"01256.64Okcenter0.0006915.284"-20"01256.64Ok0.0026915.284"-20"01256.64Okc.end0.0033915.284"-20"01256.64Ok0.0025915.284"-20"01256.64OkNotes : When r < rmin , use rmin to determine required As; Effective depth d = h - ds; ( ) - means bars shall be arranged in two layers.

C. CRACK CONTROL CHECK RESULTS : (ACI sec.10.6)LocationTop Bar Bottom Bar fs = 0.6fys1 maxs2 maxqty. of bar in 1st layers actRemarksfs = 0.6fys1 maxs2 maxqty. of bar in 1st layers actRemarks(N/mm)(mm)(mm)(mm)(N/mm2)(mm)(mm)(mm)d.end 248.40280.78304.64103.33Ok.248.40280.78304.64103.33Ok.center248.40280.78304.64103.33Ok.248.40280.78304.64103.33Ok. c.end248.40280.78304.64103.33Ok.248.40280.78304.64103.33Ok.Note : s act is the center to center spacing of rebars near the extreme tension fiber of concrete. s1 max = 94584 / fs - 2.5cc ; s2 max = 75667 / fs

D. SHEAR DESIGN : (ACI sec. 11.5, sec.21.12.3, sec. 21.12.4.2 & sec. 21.12.4.3)(Type of Seismic Risk : High)LocationQty./Dia. of LegsSprovShear ReinforcementShear CapacityRequired*Max. Stirrup/Tie SpacingRemarkAvprovAvmin1Avmin2fVcVsSreq24xTief16xMainfd/4(mm)(mm2)(cm2)(cm2)(kN)(kN)(mm)(mm)(mm)(mm)d.end 2"-10"0150157.0866.5775.23123.450.00n.a240.00320.00253.00Ok.327.212637799948center2"-10"0200157.0888.76100.30123.450.00n.a240.00320.00253.00Ok.327.212637799948c.end2"-10"0150157.0866.5775.23123.450.00n.a240.00320.00253.00Ok.327.212637799948(Note : the max. design load factor for seismic shall be doubled during analysis. Max. stirrup spacing at center shall be d/2 only.)

E. TORSION DESIGN : (ACI sec.11.6)LocationLimitEnc. AreaShear,VTorsion,TV + TPh / 8RemarkAdd. Longitudinal BarSide BarsRemarkTcr / 4AoAv/sAt/ss reqs maxAlAl minAlper side / 4Asb(kN-m)(mm2)(mm2/mm)(mm2/mm)(mm)(mm)(mm2)(mm2)(mm2)(qty-dia.)d.end 8.791168380.000.25313.21192.00Ok.255.85923.34230.832"-12"0N.Gcenter8.791168380.000.25313.21192.00N.G255.85923.34230.832"-12"0N.Gc.end8.791168380.000.25313.21192.00Ok.255.85923.34230.832"-12"0N.G(Note : Torsion effect shall be neglected when Tu< Tcr/4 ; Ao = 0.85Aoh ; Aoh = x1 y1 ; Ph = 2x1 + 2y1 ; x1,y1 = center to center dimesion of stirrups)

E.1 Check Allowable Axial Load (ACI sec.21.3.1.1)E.2 Check Crushing of Concrete Compression Struts (ACI sec.11.6.3.1)Allow.Axial, P = Agf'c/10 =576.00kN > Pu Ok.[(Vumax/bd)2 + (TumaxPh/1.7Aoh2)2]1/2


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