Sheet1I. RETAININGWALL -STEM - DESIGN FOR MAIN REINFORCEMENT1.0 DESIGN DATA.Design service moment=Ms=800.0kN.mDesign ultimate moment=M=1280.0kN.mDesign ultimate shear force=V=54kNAssumed width of slab=B=1000mmThickness of slab=D=598mmGrade of concrete=fcu=30N/mm2Grade of reinforcement=fy=425N/mm2Elastic modulus of concrete=Ec=26000N/mm2Elastic modulus of reinforcement=Es=200000N/mm2Clear cover to main reinforcement=c=75mmDesign allowable crack width=w=0.20mm

2.0 DESIGN 2.1-DESIGN FOR FLEXUREEffective depth FROM CONSIDERATION OF MOMENT522.9763603685Effective depth=d=D-c-(Dia/2)=515mmk =M / bd2fcu=0.161z=d [ 0.5 +( 0.25 - k/0.9)0.5 ] =395mmz - Max.=489mm(As)req.=M / 0.95 fy z=8027mm2(As)Prov.=Diameter=16mmSpacing=150mm=1340mm2Safety index=1340=0.17> 1OK80272.2-CHECK FOR SHEARDesign shear stress =v=V / bvd=0.11N/mm20.8[Sqrt(fcu.)] =4.4N/mm2Design shear stress.Hence no shear reinforcement requiredOK2.3. CHECK FOR CRACK WIDTHRebar spacing=S=150mmSteel ratio=r=(As)Prov. / bd=0.0026Modular ratio=ae=Es / (Ec/2)=2.0E+051.30E+04=15.38ae * r=0.040X /d=ae*r {[(1+ (2 /ae*r)]0.5 - 1}=0.246Depth of neutral axis=X=126.6mmLever arm=Z=d - X/3=472.8mmConcrete compressive stress=fcb=2Ms / Z b X=26.7N/mm2Tensile stress on steel =fs=Ms / Z As=1262.4N/mm22.3.1 Check stress levels:-Allowable comp. stress in concrete=fcb'=0.45 fcu=13.5N/mm2>fcbOKAllowable tensile stress in steel =fs'=0.8 fy=340.0N/mm2>fsOKElastic strain at surface=E1=(h-x) * fs(d-x) * Es=7.66E-03Stiffening effect of concrete (For bending only)=bt * (h-x) * (a' - x)3*Es * As * (d-x)=7.11E-04Em=E1 - Stiffening effect of concrete=6.949E-03Acr=[(S/2)2+(c+ Dia./2)2]0.5 - Dia /2=103.9mmCrack width=3 * Acr * Em1+2[(Acr-Cmin.) / (h-x)]=1.929mm< Allowable crack width.OK

2.4. DESIGN FOR DISTRIBUTION REINFORCEMENT

Min. % of steel required=Astmin=777mm2/m(As)Prov.=Diameter=16mm=Spacing=150mm=1340mm2Safety index=1340=1.72> 1OK777