function z=column13920Volume(x)

%cc=4400/1000^3; %M20
cc=4550/1000^3; %M25
%cc=4750/1000^3; %M30
%cc=5000/1000^3; %M35

%cs=353250/1000^3; %fy415 (7850kg/m^3, 7850*45=353250) %(steel density=78.50kN/m^3, 78.50*100kg/m^3, 7850kg/m^3)
cs=392500/1000^3; %Fy500
%cs=431750/1000^3; %fy550 (7850*54=431750)

l=7000;

cf=100/1000^2; %Cost of Formwork
% IS13920 length cases for special confining reinf.
l1= (l/6)*4; % length for special confining reinforcement at each joint/on either side...it should be 1/6th of clear span.
l2= l-((l/6)*4); %transverse reinf at centre.
no_of_bars_sides=(l1/x(6))+1;
no_of_bars_centre=(l2/x(7))+1;

%z=cc*((x(1)*x(2)*l)-((.7853*x(3)^2*x(4)*l)+(.7853*x(5)^2*((l/x(6))+1)*(x(1)+x(2)*2) )))...
%+cs*((.7853*x(3)^2*x(4)*l)+(.7853*x(5)^2*(l/x(6)+1)*(x(1)+x(2))*2 )) +...
%cf*(x(1)+x(2)*2*l);

z=cc*((x(1)*x(2)*l)-((.7853*x(3)^2*x(4)*l)+(.7853*x(5)^2*(no_of_bars_sides+no_of_bars_centre)*(x(1)+x(2)*2) )))...
+cs*((.7853*x(3)^2*x(4)*l)+(.7853*x(5)^2*(no_of_bars_sides+no_of_bars_centre)*(x(1)+x(2))*2))+ ...
cf*((x(1)+x(2))*2*l);