箱涵淹没压力流和无压流水力计算程序

无压流涵洞计算洞宽B,,,,公式来源：《灌溉与排水渠系建筑物设计规范》（SL482-2011),,,

"适用条件：H<1.2D,h<D(H为进口水深，D为涵洞高，h为出口水深，单位:m)",,适应计算,,,,,

一、涵洞断面宽度计算,值,备注,,,,,

1.基本资料：,,,例题,,,,

设计流量Q(m3/s),2.78,黄色底纹标记为需要手动输入部分,3.45/3.48,,,,

涵洞净高D(m),2,净高不宜小于1.8m,4,,,,

涵洞长度L(m),40,涵洞长度,30/100,,,,

涵洞纵坡i,0.0005,纵坡不宜大于5%,0.002,,,,

涵洞糙率系数n,0.014,涵洞糙率,0.014,,,,

进口断面水深H(m),1.61,进口断面水深应大于出口断面水深,4.05,,,,

进口断面行近流速V（m/s),1,,0.7,,,,

出口水深h(m),1.42,出口水深应小于进口断面水深,3.5,,,,

动能修正系数α,1.05,可采用1.05,1.05,,,,

流量系数m,0.36,可采用0.36,0.36,,,,

侧收缩系数ε,0.95,可近似取0.95,0.95,,,,

重力加速度g,9.81,g=9.81,9.81,,,,

2.涵洞宽度计算,,,,,,,

1)流态判别,,,,,,,

"H<1.2D,h<D,满足无压流涵洞要求",,,,,,,

"长洞与短洞判别：(L<8H,短洞；L≥8H,长洞）",,,,,,,

长洞,,,,,,,

2）短洞过流能力计算：,,不适应短洞计算公式计算,,,,,

包括行近流速水头在内的进口水深H0=H+a*V^2/(2g),,,4.08,,,,

hs=h-i*L,,,3.44,,,,

σ=2.31*hs/H0*(1-hs/H0)^0.4,,,0.928,,,,

B=Q/σ*ε*m*(2g)^0.5*H0^(3/2),,,3.45,,,,

3）长洞过流能力计算,,适应L≥8H长洞计算公式计算,,,,,

假定涵洞的宽度B,1.5,计算方法：,1.498333552,,,,

包括行近流速水头在内的进口水深H0=H+a*V^2/(2g),1.664,1.假定长洞的洞宽B,4.08,,,,

(1)计算涵洞正常水深h0,,2.计算涵洞正常水深h0,,,,,

假定正常水深h0,1.777,用单变量求解法：,3.296,,,,

断面积W0=B*h0,2.666,目标单元格为流量差Q-Q0，目标单元格值为0,,,,,

湿周X0=B+2*h0,5.055,可变单元格为正常水深h0,,,,,

水力半径R0=W0/X0,0.527,3.假定进口水深hs,,,,,

谢才系数C0=(1/n)*R0^(1/6),64.20,用单变量求解法计算：,,无压涵洞的净空要求：,,,

设计流量Q0=W0*C0*(i*R)^(1/2),2.780,目标单元格为进、出口能量差E1-E2,,1.净空面积不小于洞身横断面面积的10%～30%。,,,

流量差dQ=Q-Q0,0.000,目标单元格值为0,,2.净空高度概根据涵洞断面型式及洞身高度确定，见下表，并应不小于0.4m。,,,

(2)计算涵洞的临界水深hk=(a*q^2/g)^(1/3),0.72,可变单元格为洞进口水深hs,,进口净高(m),断面型式,,

(3)确定出口断面控制水深h,1.42,4.根据计算的洞宽重新输入假定洞宽B=(B+B1)/2,,,圆涵,拱涵,矩形涵洞

（4）用能量方程试算上游水深hs,,"5.重复试算h0和hs,直到洞宽差为0",,≤3,≥D/4,≥D/4,≥D/6

假定洞进口内水深hs(m）,0.470,,3.463,>3,≥0.75m,≥0.75m,≥0.5m

洞进口内过水断面积W1=B*hs,0.705,1.5*0.47,,满足检修要求的涵洞最小断面应为：,,,

洞进口断面湿周X1=B+2*hs,2.440,1.5+2*0.47,,净宽：1.5m，净高1.8m.,,,

洞进口断面水力半径R1=W1/X1,0.289,0.705/2.44,,,,,

洞进口断面谢才系数C1=(1/n)*R1^(1/6),58.077,0.289^(1/6)/0.014,,,,,

洞进口断面流速V1=Q/W1,3.943,2.78/0.705,,,,,

进口断面能量E1=hs+a.V1^2/(2g)+i*L,1.322,0.47+1.05*3.943^2/(2*9.81)+0.0005*40,,,,,

出口内过水断面积W2=B*h,2.13,1.5*1.42,,,,,

出口断面湿周X2=B+2*h,4.34,1.5+2*1.42,,,,,

出口断面水力半径R2=W2/X2,0.491,2.13/4.34,,,,,

出口断面谢才系数C2=(1/n)*R2^(1/6),63.439,0.491^(1/6)/0.014,,,,,

出口断面流速V2=Q/W2,1.305,2.78/2.13,,,,,

平均水力半径Rp=(R1+R2)/2,0.390,(0.289+0.491)/2,,,,,

平均谢才系数Cp=(C1+C2)/2,60.758,(58.077+63.439)/2,,,,,

平均流速Vp=(V1+V2)/2,2.624,(3.943+1.305)/2,,,,,

水面平均比降Jp=Vp^2/(Cp^2*Rp),0.005,2.624^2/(60.758^2*0.39),,,,,

出口断面能量E2=h+a.V2^2/(2g)+Jp*L,1.703,1.42+1.05*1.305^2/(2*9.81)+0.00479*40,,,,,

进出口断面能量差E1-E2,-0.380,1.322-1.703,,,,,

淹没系数：σ=2.31*hs/H0*(1-hs/H0)^0.4,0.571,2.31*0.47/1.664*(1-0.47/1.664)^0.4,0.921,,,,

计算洞宽：B1=Q/σ*ε*m*(2g)^0.5*H0^(3/2),1.497,2.78/(0.571*0.95*0.36*(2*9.81)^0.5*1.664^(3/2)),,,,,

计算宽度差:DB=B-B1,-0.003,1.497-1.5,,,,,

计算流量：Q=σ*ε*m*B*(2g)^0.5*H0^(3/2),2.79,0.571*0.95*0.36*1.5*(2*9.81)^0.5*1.664^3/2,,,,,

,,,,,,,,

二、消力池计算,,,,,,,

1.基本资料,,,,,,,

消力池进口宽度B1(m),1.8,,,,,,

消力池出口宽度B2(m),6.05,,,,,,

出口洞底至下游渠底的跌差P(m),0,,,,,,

下游渠道水深hs(m),1,,,,,,

斜坡段坡度1:m,4,,,,,,

动能修正系数α,1.05,,,,,,

流速系数φ,0.95,,,,,,

水跃淹没系数σ0,1.05,,,,,,

水跃长度校正系数β,0.75,,,,,,

消力池进口单宽流量q1=Q/B1,1.544,2.78/1.8,,,,,

消力池出口单宽流量q2=Q/B2,0.459504132,2.78/6.05,,,,,

2.消力池计算：,,,,,,,

1）判别是否需要修建消力池,,,,,,,

"T0=max(h,hk)+a.V^2/(2.g)+P",1.511,1.42+1.05*1.305^2/(2*9.81)+0),,,,,

假定收缩水深hc1(m),0.666,,,,,,

hc^3-T0.hc^2+a.q1^2/(2g.φ^2)=0,-0.240,0.666^3-1.511*0.666^2+1*1.544^2/(2*9.81*0.95^2),,,,,

hc2=hc1/2*((1+8a.q^2/(g.hc1^3))^0.5-1),0.584,0.666/2*((1+8*1*1.544^2/(9.81*0.666^3))^0.5-1),,,,,

hc2≤hs,不需设消力池,,,,,,

2）计算消力池池深d(m),,,,,,,

假定消力池池深d=,0.6,,,,,,

上游断面比能为：E=T0+d,2.111,1.511+0.6,,,,,

假定收缩水深hc1(m),0.569,,,,,,

hc1^3-T0.hc1^2+a.q1^2/(2g.φ^2)=0,-0.36,0.569^3-2.111*0.569^2+1*1.544^2/(2*9.81*0.95^2),,,,,

hc2=hc1/2*((1+8a.q1^2/(g.hc1^3))^0.5-1)（B1/B2)^0.25,0.504,0.569/2*((1+8*1*1.544^2/(9.81*0.569^3))^0.5-1)*(1.8/6.05)^0.25,,,,,

△Z=a.q2^2/(2g.φ^2.hs^2)-a.q2^2/(2g.hc2^2),-0.030,1*0.459504132231405^2/(2*9.81*0.95^2*1^2)-1*0.459504132231405^2/(2*9.81*0.504^2),,,,,

d1=σ0.hc2-hs-△Z,-0.440,1.05*0.504-1--0.03,,,,,

池深差：d1-d,-1.040,,,,,,

3）消力池长度计算：,,,,,,,

水跃长度Lj=6.9×(hc2-hc1),-0.45,6.9*(0.504-0.569),,,,,

斜坡段长度Ls=m×(P+d),2.4,4*(0+0.6),,,,,

消力池长度：Lsj=Ls+β.Lj,2.06,2.4+0.75*-0.447,,,,,

三、消力池底板厚度计算,,参照SL265-2011《水闸设计规范》,,,,,

1.基本资料,,,,,,,

消力池进口处的单宽流量q(m3/s.m),1.544,,,,,,

上游总水头H0(m),2.111,,,,,,

消力池底板计算系数k1(可采用0.15～0.20）,0.15,,,,,,

消力池底板安全系数k2(可采用1.1～1.3）,1.2,,,,,,

消力池底板的饱和重度γb(kN/m3),24,,,,,,

消力池跃前收缩水深hc1(m),0.569,,,,,,

消力池跃后水深hc2(m),0.504,,,,,,

消力池跃前收缩断面流速Vc(m/s),2.714,1.544/0.569,,,,,

2.按抗冲要求计算消力池底板厚度t(m),,,,,,,

,0.225,0.15*(1.544*(2.111)^0.5)^0.5,,,,,

取消力池的底板厚度（等厚）为：t=,0.5,,,,,,

3.按抗浮要求验算,,,,,,,

消力池底板顶面的水重（水深为跃后水深）：W=γ.hc2,5.04,10*0.504,,,,,

消力池底板上的脉动压力（跃前收缩断面流速水头的5%）Pm=0.05γ.Vc^2/(2g),0.19,0.05*10*2.714^2/(2*9.81),,,,,

消力池底板底面的扬压力：U=γ(hc2+t),10.04,10*(0.504+0.5),,,,,

消力池底板安全系数：,2.31,24*0.5/(10.043-5.043+0.188),,,,,

"抗浮安全系数k2大于1.1～1.3,安全",,,,,,,

,,,,,,,,

四、海漫长度计算,,,,,,,

基本资料,,,,,,,

消力池末端单宽流量qs=Q/B2,0.460,,,,,,

上游总水头T0(m),2.111,,,,,,

海漫长度计算系数ks,7,粉砂、细砂13～14；中砂粗砂、粉质壤土11～12；粉质黏土9～10；坚硬黏土7～8,,,,,

当满足：,0.817099932,(0.459504132231405*(2.111)^0.5)^0.5,,,,,

海漫长度：,5.72,7*0.817,,,,,