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/CH12/EX12.3/Ex12_3.sce | 68 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 3683/CH12/EX12.3/Ex12_3.sce (limited to '3683/CH12/EX12.3/Ex12_3.sce') diff --git a/3683/CH12/EX12.3/Ex12_3.sce b/3683/CH12/EX12.3/Ex12_3.sce new file mode 100644 index 000000000..ada5ef959 --- /dev/null +++ b/3683/CH12/EX12.3/Ex12_3.sce @@ -0,0 +1,68 @@ +sigma_cbc=5//in MPa +sigma_st=230//in MPa +phi=30//angle of repose, in degrees +H=5//height of wall, in m +B=0.6*H//assume, in m +T=B/4//assume toe to base ratio as 1:4 +t=450//thickness of wall, in mm +W=16//density of retained earth, in kN/cu m +P=W*H^2/2*(1-sind(phi))/(1+sind(phi))//in kN +P=67//assume, in kN +y=1.8//in m +P=67//in kN +Wt=223//in kN +D=0.5//thickness of base, in m +x=1.8-P*(H/3+D/10^3)/Wt//in m +x=1.15//in m +e=B/2-x//in m +q1=Wt/B+Wt*e/(1*B^2/6)//maximum pressure, in kN/sq m +q2=Wt/B-Wt*e/(1*B^2/6)//minimum pressure, in kN/sq m +Pa=q1-(q1-q2)/B*T//pressure at A, in kN/sq m +Pa=100//assume, in kN/sq m +Pb=q1-(q1-q2)/B*(T+t/10^3)//pressure at B, in kN/sq m +Pb=85//assume, in kN/sq m +Ma=Pa*T^2/2+1/2*(q1-Pa)*T*2/3*T-T*D*25*T/2//bending moment at A, in kN-m +Ma=30//round-off, in kN-m +Mb=(B-T-t/10^3)^2*H*W/2+(B-T-t/10^3)^2*D*25/2-q2*(B-T-t/10^3)^2/2-(Pb-q2)*1/3*(B-T-t/10^3)^2/2//bending moment at B, in kN-m +Mb=80//in kN-m +//design of toe +d=sqrt(Ma*10^6/0.65/10^3)//in mm +D=d+10/2+70//<500 mm (provided), hence OK +D=500//in mm +d=D-70//in mm +Ast=Ma*10^6/sigma_st/0.9/d//in sq mm +Astmin=0.12/100*10^3*D//in sq mm +Ast=max(Ast,Astmin)//in sq mm +s1=1000*0.785*10^2/Ast//in mm +s1=130//assume, in mm +//distribution steel is same as above +//check for shear +V=(q1+Pa)/2*T//in kN +Tv=V*10^3/10^3/d//in MPa +//for M15 grade concrete and pt=0.32 +Tc=0.2368//in MPa +//as Tc > Tv, no shear reinforcement required +//development length +dia=10//in mm +Tbd=0.84//in MPa +Ld=dia*sigma_st/4/Tbd//in mm +Ld=685//assume, in mm +//design of heel +d=sqrt(Mb*10^6/0.65/10^3)//< 430 mm (provided), hence OK +d=430//in mm +Ast=Mb*10^6/sigma_st/0.9/d//in sq mm +s2=1000*0.785*10^2/Ast//in mm +s2=85//assume, in mm +//distribution steel: 0.12% of Ag, hence provide 10 mm dia bars @ 130 mm c/c +V=(B-T-t/10^3)*H*W-(Pb+q2)/2*(B-T-t/10^3)//in kN +Tv=V*10^3/10^3/d//in MPa +//for M15 grade concrete and pt=0.32 +Tc=0.2368//in MPa +//as Tc > Tv, no shear reinforcement required +//development length +dia=10//in mm +Tbd=0.84//in MPa +Ld=dia*sigma_st/4/Tbd//in mm +Ld=685//assume, in mm +mprintf("Summary of design:\nThickness of base slab=%d mm. Refer to Fig. 12.11 of textbook for reinforcement details.",D) +//answer in textbook for spacing of 10 mm dia bars for main steel in toe and distribution steel is incorrect -- cgit