isdftng

11/14/13 5:10 PM C:\Users\himanshu\Downloads\isdftng. m 1 of 3

fprintf( ' \t \t \t \t \t \t \t \t isolated footing design \ n' );fprintf( 'method of solving is by LIMIT STATE METHOD (LSM) \ n' );l=input( 'enter length of column section (mm) = ' );b=input( 'enter width of column section (mm) = ' );C=input( 'grade of concrete =M ' );T=input( 'grade of seel(fe250/fe415/fe500) =fe ' );P=input( 'load from column(KN)= ' );q=input( 'safe bearing capacity of soil(KN/m2)= ' );fprintf( 'SIZE OF FOUNDATION \n' );fprintf( 'load from column = %f KN \n' ,P);

fw=0.1*P;fprintf( 'foundation self weight = %f KN \n' ,fw);tl=P+0.1*P;fprintf( 'Total load = P+0.1*P = %f KN \n' ,tl);A1=tl/q;fprintf( 'area of footing required = %f m2 \n' ,A1);A=round(A1)+1;fprintf( 'area of footing provided= %d m2 \n' ,A);y=l/b;B=sqrt(A/y);L=y*B;fprintf( 'width of footing section = %f m \n' ,B);

fprintf( 'length of footing section = %f m \n' ,L);w0=P/A;fprintf( 'net upward soil pressure = %f KN/m2 \n' ,w0);wu0=1.5*w0;fprintf( 'factored upward soil pressure = %f KN/m2 \n' ,wu0);fprintf( '\n CHECK FOR BENDING MOMENT \n' );fprintf( 'Assuming 1m strip at critical section \n' );Muy=(wu0*(L-(l/1000))^2)/8;fprintf( 'factored moment at face of width of column = %f KN m \n' ,Muy);%calculationsif (T==250) k = 0.53;

elseif (T==415) k = 0.48;else k = 0.46;endj=(1-0.42*k);Q=0.36*C*k*(1-0.42*k);d=sqrt((Muy*1000000)/(Q*1000));d=round(d)+1;fprintf( 'depth required for footing = %d mm \n' ,d);cover=input( 'effective cover (mm) = ' );

D=d+cover;fprintf( 'Total depth of footing = %d mm \n' ,D);% check for one way shearfprintf( 'ONE WAY SHEAR \n' );O=(L-(l/1000))/2-(d/1000);% maximum shear forceV=wu0*1*O;


tv=((V*1000)/(1000*d));fprintf( 'shear stress acting at distance d from face of col umn = %f N/mm2 \n' ,tv);tc=0.28;fprintf( 'permissible shear stress in LSM = %f N/mm \n' ,tc)if tv<tc fprintf( 'depth is safe against shear \n' );else fprintf( 'as tv = %f N/mm2 >tc= %f N/mm2 , depth failed agai nst shear \n' ,tv,tc); fprintf( 'depth has to be revised \n' );end

while tv>tc d=d+1; O=(L-(l/1000))/2-(d/1000); V=wu0*1*O; tv=((V*1000)/(1000*d));endfprintf( 'effective depth of footing provided = %d mm \n' ,d);D=d+cover;fprintf( 'total depth of footing provided = %d mm \n' ,D);% checking of punching shearfprintf( 'CHECK FOR PUNCHING SHEAR \n' );

npf=(P*1.5-wu0*((l+d)/1000)*((b+d)/1000))*1000;ra=2*((l+d)+(b+d))*d;tvp=npf/ra;fprintf( 'punching shear stress acting at section d/2 from f ace of column = %f N/mm2 \n' ,tvp);tvpc=0.25*(sqrt(C));fprintf( 'permissible punching shear stress is = %f N/mm2 \ n' ,tvpc);if tvp>tvpc fprintf( 'as tvp = %f N/mm2 > tvpc= %f N/mm2 , depth failed against shear \n' ,tvp,tvpc); fprintf( 'depth has to be revised \n' ); while tvp>tvpc

d=d+1; npf=(P*1.5-wu0*((l+d)/1000)*((b+d)/1000))*1000; ra=2*((l+d)+(b+d))*d; tvp=npf/ra; end fprintf( 'revised of effective footing = %d mm \n' ,d); D=d+cover; fprintf( 'revised total depth of footing = %d mm \n' ,D);else fprintf( 'depth is safe against punching shear \n' );end

% area of steel providedAsty=(Muy*1000000)/(0.87*T*j*d);Asty=B*Asty;fprintf( 'area of steel to be provided = %f mm2 \n' ,Asty);dia=input( 'diameter of bars to be provided = ' );n=(Asty*4)/(3.14*dia*dia);n=round(n)+1;


fprintf( 'provide %d number %d mm diameter bars along the l ength \n' ,n,dia);Mux=(wu0*(B-(b/1000))^2)/8;fprintf( 'factored moment at face of length of column sectio n = %f KNm \n' ,Mux);Astx=(Mux*1000000)/(0.87*T*j*d);Astx=L*Astx;fprintf( 'area of steel to be provided = %f mm2 \n' ,Astx);dia2=input( 'diameter of bars to be provided = ' );n2=(Astx*4)/(3.14*dia2*dia2);n2=round(n2)+1;nc=n2*(2/(1+y));

nc=round(nc);fprintf( 'provide %d number %d mm diameter bars in central band \n' ,nc,dia2);n3=n2-nc;fprintf( 'provide %d number %d mm diameter bars in each sid e band along length \n' ,n3,dia2);disp( 'design completed' );

isdftng

Documents