From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2087/CH12/EX12.3/example12_3.sce | 161 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100755 2087/CH12/EX12.3/example12_3.sce (limited to '2087/CH12/EX12.3') diff --git a/2087/CH12/EX12.3/example12_3.sce b/2087/CH12/EX12.3/example12_3.sce new file mode 100755 index 000000000..4140d389f --- /dev/null +++ b/2087/CH12/EX12.3/example12_3.sce @@ -0,0 +1,161 @@ + + +//example 12.3 +//design a vertical drop weir on Bligh's theory +//test floor by Khosla's theory +clc;funcprot(0); +//given +Q=2800; //maximum flood discharge +hfl=285; //H.F.L before construction +hw=278; //minimum water level +fsl=284; //F.S.L of canal +c=12; //coefficient of creep +flux=1; //allowable afflux +Ge=1/6; //permissible exit gradient +rho=2.24; //specific gravity of concrete + +//Hydraulic calculation +L=4.75*Q^0.5; +q=Q/L; +q=round(q*10)/10; +mprintf("Hydraulic calculation:"); +mprintf("\ndischarge per unit width of river=%f cumecs.",q); +f=1; +R=1.35*(q^2/f)^(1/3); +R=round(R*100)/100; +mprintf("\nregime scour depth=%f m.",R); +V=q/R; //regime velocity +vh=V^2/(2*9.81); //velocity head +l_down=hfl+vh; +l_up=l_down+flux; +hfl_up=l_up-vh; +hfl_down=hfl-0.5; +hfl_down=round(hfl_down*100)/100; +mprintf("\nactual d/s H.F.L allowing 0.5 m for retrogation=%f m.",hfl_down); +K=(q/1.7)^(2/3); +cl=l_up-K; //crest level +cl=round(cl*100)/100; +mprintf("\ncrest level=%f m.",cl); +pl=fsl+0.5; //pond level +s=hfl_down-cl; //heigth of shutter +mprintf("\nheigth of shutter=%f m.",s); +rl_up_pile=hfl_up-1.5*R; //R.L of bottom u/s pile +d_up_cut=hw-276; //depth of upstream cut-off +mprintf("\ndepth of upstream cut-off=%f m.",d_up_cut); +mprintf("\n provide concrete cut off 2 m depth."); +rl_bot_ds=hfl_down-2*R; +Hs=hfl_down-hw; //seepage head +Hc=cl-hw; //heigth of crest +mprintf("\nR.L of gates crest=%f m.",Hs); +mprintf("\nHeigth of crest=%f m.",Hc); + +//design of weir wall +d=hfl_up-cl; +a=d/(rho)^0.5; +a=3*d/(2*rho); //from sliding consideration +a=s+1; //from practical consieration +a=a+1; +mprintf("\n\ndesign of weir wall:") +mprintf("\nprovide top width of %i m.",a); +Mo=9.81*Hs^3/6; //overtirning moment +//equating the moment of resistance to overturning moment and putting the values we get +y=poly([-1.084,0.020,0.039],'x','c'); +b=roots(y); +//we get b= - 5.5347261 and 5.0219056 +//taking +b=5; +//when weir is submerged +C=0.58; +d=(q^2/((2*C/3)^2*2*9.81))^(1/3); +Mo=9.81*d*Hc^2/2; +//from equation of moment of resistence we get +y=poly([-77.55,3,1],'x','c'); +b=roots(y); +//we get b= - 10.433085 and 7.4330846 +//taking +b=8; +mprintf("\nbottom width=%i m.",b); + +//design of impervious and pervious aprons +C=12; +L=C*Hs; +mprintf("\n\ndesign of impervious and pervious aprons:"); +mprintf("\ntotal creep length=%i m.",L); +l1=2.21*C*(Hs/13)^0.5; +l1_=l1+1; +mprintf("\nlength of downstream impervious apron=%i m.",l1_); +d1=hw-276; +d2=hw-271; +l2=L-l1-(b+2*d1+2*d2); +mprintf("\nlength of upstream impervious apron=%i m.",l2); +l3=18*C*(Hs*q/975)^0.5; +mprintf("\ntotal length of d/s apron=%i m.",l3); //calculation is wrong in book +l=l3-l1; +le=l/2; +le=round(le*100)/100; +mprintf('\nprovide filter of length %f m. and launching apron of length %f m.',le,le); +t=d2*10^0.5/le; +mprintf("\nthickness of launching apron in horizontal position=%f m.",t); +mprintf("\nprovide launching apron of thickness 1.5 m."); +T=2*d1; +V=d1*10^0.5; +ta=V/T; +ta=round(ta*10)/10; +mprintf("\nthickness of apron in horizontal position=%f m.",ta); +Hr=Hs-Hs*(4+33+8)/L; +t=4*Hr/(3*(rho-1)); +t=round(t*10)/10; +mprintf('\nprovide thickness of %f m from d/s of weir wall to point 6 m from it.',t); +Hr=Hs-Hs*(4+33+8+6)/L; +t=4*Hr/(3*(rho-1)); +t=round(t*10)/10; +mprintf("\nprovide thickness of %f m from 6 m to 12 m from d/s end of weir wall.",t); +Hr=Hs-Hs*(4+33+8+12)/L; +t=4*Hr/(3*(rho-1)); +t=round(t*10)/10; +mprintf("\nprovide thickness of %f m for rest of length of weir floor.",t); + +//check by khosla's theory +b=33+8+19; //total horizontal length of impervious floor +d=7; //depth of downstream pile +alpha=b/d; +n=0.14; //n=1/%pi*(lambda)^0.5; +Ge=Hs*n/d; +mprintf("\n\ncheck by Khosla theory:"); +mprintf("\nexit gradient=%f. < 1/6\n hence safe",Ge); +alpha_=d/b; +fic1=0.83;fid1=0.88; +corec_c1=(fid1-fic1)*100/2; +bdash=b; +d=2;D=7; +C1=19*(D/bdash)^0.5*(d+D)/b; +fic1=fic1*100+corec_c1+C1; +Pc=Hs*fic1/100; //pressure head at C +alpha_=d/b; +fie2=0.31;fid2=0.21; +corec_e1=(fie2-fid2)*1.7*100/7; +bdash=b; +d=7;D=2; +C1=19*(D/bdash)^0.5*(d+D)/b; +fie2=fie2*100-corec_e1-C1; //in book 3.53 value is wrong +Pe=Hs*fie2/100; //pressue head at E +//assuming linear variation of pressure for intermediate points +Pa=Pc-(Pc-Pe)*(33+8)/b; +t=Pa/1.24; +Pa=round(Pa*100)/100; +t=round(t*100)/100; +mprintf("\npressure at d/s of weir wall=%f m.",Pa); +mprintf("\nthickness at d/s of weir wall=%f m. < thickness by Bligh theory;\nhence safe.",t); +Pb=Pc-(Pc-Pe)*(33+8+6)/b; +t=Pb/1.24; +Pa=round(Pa*100)/100; +t=round(t*100)/100; +mprintf("\npressure at 6 m from d/s of weir wall=%f m.",Pb); +mprintf("\nthickness at 6m from d/s of weir wall=%f m. < thickness by Bligh theory;\nhence safe.",t); +Pc=Pc-(Pc-Pe)*(33+8+12)/b; +t=Pc/1.24; +Pa=round(Pa*100)/100; +t=round(t*100)/100; +mprintf("\npressure at 12 m from d/s of weir wall=%f m.",Pc); +mprintf("\nthickness at 12m from d/s of weir wall=%f m. > thickness by Bligh theory;\nhence unsafe.",t); +mprintf("\nhence increase th ethickness to 1.9 m for a length of 7 m of impervious floor."); -- cgit