From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 3683/CH11/EX11.3/Ex11_3.sce | 48 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 3683/CH11/EX11.3/Ex11_3.sce (limited to '3683/CH11/EX11.3/Ex11_3.sce') diff --git a/3683/CH11/EX11.3/Ex11_3.sce b/3683/CH11/EX11.3/Ex11_3.sce new file mode 100644 index 000000000..13303fb88 --- /dev/null +++ b/3683/CH11/EX11.3/Ex11_3.sce @@ -0,0 +1,48 @@ +B=0.5//column diameter, in m +fck=20//in MPa +sigma_cbc=7//in MPa +sigma_st=230//in MPa +P1=1600//load on column, in kN +P2=0.05*P1//weight of footing, in kN +P=P1+P2//in kN +q=300//bearing capacity of soil, in kN/sq m +A=P/q//in sq m +L=sqrt(A)//assuming footing to be square +L=2.4//assume, in m +p=P1/L^2//soil pressure, in kN/sq m +p=278//assume, in kN/sq m +bc=1 +ks=0.5+bc//>1 +ks=1 +Tc=0.16*sqrt(fck)*10^3//in kN/sq m +Tv=Tc +//let d be the depth of footing in metres +//case I: refer Fig. 11.11 of textbook +d1=L*(L-B)/2*p/(Tc*L+L*p)//in m +//case II: refer Fig. 11.12 of textbook; we get a quadratic equation of the form e d^2 + f d + g = 0 +e=%pi/4*p+%pi*Tc +f=2*%pi/4*B*p+%pi*B*Tc +g=-(L^2-%pi/4*B^2)*p +d2=(-f+sqrt(f^2-4*e*g))/2/e//in m +d2=0.57//assume, in m +d=max(d1,d2)//in m +//bending moment consideration, refer Fig. 11.13 of textbook +M=1*((L-B)/2)^2/2*p//in kN-m +d3=sqrt(M*10^6/0.88/10^3)//<570 mm, hence OK +z=0.9*d*10^3//lever arm, in mm +Ast1=(M*10^6/sigma_st/z)//in sq mm +Ast=L*Ast1//steel required for full width of 2.4 m +//provide 20 mm dia bars +dia=20//in mm +n=Ast/0.785/dia^2//no. of 20 mm dia bars +n=9//assume +Tbd=1.12//in MPa +Ld=dia*sigma_st/4/Tbd//in mm +Ld=1030//assume, in mm +c=50//side cover, in mm +La=(L-B)/2*10^3-c//in mm +//bend bar at right angle and provide length, l +l=Ld-La//in mm +D=d*10^3+dia/2+100//in mm +mprintf("Summary of design:\nOverall depth of footing=%d mm\nCover:100 mm bottom; 50 mm side\nSteel:%d-20 mm dia bars both ways",D,n) +//answer in textbook is incorrect -- cgit