Design of RCC cantilever beam

step-1  Compute depth of beam :-
               Leff./d  = 7              d=effective depth.
                   D=d+(ⲫ/2)+cover    ⲫ=dia of bar
        generally , in case of cantilever beam moment is varied and at free                end  its value is zero , so we reduce the depth of beam at free end.
        if we take an example then if 400mm depth at fixed end then at free 
       end provided 200mm. 

cantilever beam design :

step-2  loading and moment calculate & check the depth -
               M=0.36fckbxu(d - 0.42xu)        M= Factored moment
                                                                                  b= width of beam
                                                                                  d= depth of beam required
                                                                                  xu= neutral axis
if depth is ok then continue.

step-3 compute steel -
       M= 0.87fyAst(d - 0.42xu)
Now asssume dia. of bar and compute no. of bars are required.
step-4  curtailment of beam -
in case of curtailment assume a section and calculate depth and moment at this depth. as per this moment steel is provided . generally it is most important to save my money.
step-5 determine spacing  -
in this step determination of spacing of stirrups .
it depends on the permissible shear strength.
         a. determine  τv & τc , 
                   τv= shear force/b•d
           if τv>τc then design required.
           if τc/2 < τv < τc then minimum shear reinforcement provides.
             Sv= (0.87fyAsv)/0.4b             Sv=spacing of stirrups
                                                            Asv= area of stirrups