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1、K0+438.00涵洞孔径计算(i)选择涵洞孔径 汇水面积：F = 0.432km2采用经验公式，设计流量：Q二中 -uF pP其中：S p = 100, u = KSp = *100。.71= 26.3, W = 0.76, m = l, 2 = 0.67Qz = 0.76 x Goo-26.3)x 0.432。.67=31.92 mays设涵洞进水口净高：h =2.5m dh -A涵前水深：H =U.o /2.5- = 2.39m0.87D Q涵洞宽度：B = P71.581x 的 3L92=5.46m1.581x2.3932r q 丫；选一净跨径L = 6m的钢筋混凝土盖板涵，此时涵前实
2、际水深:H = 一乙一=2.25m1.581xL /、o7因此，进水口水深：H= 0.87H = 1.95mh66查表 5-8, N ，则涵洞净高 h】 H = x 1.95 = 2.35m 2.5m6d 55(2)确定h、h、V、V k c k c此时，临界水深。=0.6435H = 1.45 m k收缩断面水深：h = 0.9/z = 1.30m ck收缩断面流速:0.134；(2.25a-l?，则涵洞净高hd 5H = 6x 1.99 = 2.39m 2.5m（2）确定h、h、匕、Vc此时，临界水深hk=0.591H = 1.35m收缩断面水深:=0.9七=1.22m收缩断面流速:1V
3、0.134 )12 = 4.13 m. sV = 6 m. s y 临界流速：Vk=0.9V = 3.72 m/s V = 6 mJs（3）计算临界坡度:水力半径:r 二 _Bxh = 10x 1.35 -ism k PkB + 2hk10 + 2 x 1.35二二 rx2.16 m 2k C2Rkr；3I 1.062； J=0.328%imax满足要求，故选取涵洞2 5.0 x 2.5mK3+692.00涵洞孔径计算（1）选择涵洞孔径汇水面积：F = 0.854m2采用经验公式，设计流量：Qp=wGp-u晶其中：Sp = 100，u = KS = 1x 1000.71= 26.3，Qr =
4、0.76 x(100 26.3)x 0.8540.67W = 0.76，m = 1，人20.67=50.39 m3, s设涵洞进水口净高：h = 3mdh 涵前水深：H = d0.873 3一6 = 2.87m 0.87涵洞宽度：B =*1.366 x H321.366 x 2.873250.39=7.59m 铝 8mr q y；选一净跨径L = 8m的拱涵，此时涵前实际水深：H = 1 %6虹=277mX .0 /因此，进水口水深：H = 0.87H = 2.41m查表 5-8, A |，则涵洞净高 hd 5 H = 6 x 2.41 = 2.89m 总 3m（2）确定h七、VV此时，临界水
5、深hk = 0.6435H = 1.78m收缩断面水深：气=0.9、= 1.60m收缩断面流速:0H4)y 0.134 y1 y 0.134 )12 = 455m/s V = 6m/s y临界流速：Vk=0.9Vc=4.10 m sV = 6m. sy（3）计算临界坡度:水力半径:wR = =k PkB x h kB + 2h k8 X 侦8 = 1.23m8 + 2 x 1.78V 2(n X V ( 0.016 X 4.112=k =k= :kC2RkRk43y 1.2323)=0.326%imax满足要求，考虑甲方排水要求，故选取涵洞2-4.0x4.5mK4+832.50涵洞孔径计算（1
6、）选择涵洞孔径汇水面积：F = 0.598m2采用经验公式，设计流量：Qp=wGp-u晶其中：Sp = 100，u = KS = 1x 1000.71= 26.3，Qz = 0.76 x(100 - 26.3)x 0.5980.67W = 0.76，m = 1，人 2 = 0.67=39.68 m3 .s设涵洞进水口净高：h = 2mdh1 A涵前水深：H = d0.872 - 2 6 = 1.92m 0.87涵洞宽度：B =夷39.68=10.92m 总 11m1.366 x H32 1.366 x 1.9232选一净跨径L0 = 11m的拱涵，此时涵前实际水深:因此，进水口水深：H = 0
7、.87H = 1.63m123=1.87m查表 5-8，A ，则涵洞净高 hd 6 H = 6 x 1.63 = 1.96m 总 2m（2）确定h七、VVc此时，临界水深k= 0.6435H = 1.20m收缩断面水深：h 0.9/z 1.08mck收缩断面流速:H羊 0.134/(1.87 )0.134/= 3.74m/sV = 6m/sy临界流速：V =0.9V =3.37m/sV =6m/s kcy（3）计算临界坡度:水力半径: coR = =k PkBxh 111x1.2 CM =0.99mB + 2h 11 + 2x1.2k0.016x3.37= 0.297%imax满足要求，考虑甲
8、方排水要求，故选取涵洞2-5.5x2mK5+291.00涵洞孔径计算（1）选择涵洞孔径汇水面积：F = 0.65km2采用经验公式，设计流量：Q =P其中：S = 100U = KSP1 = 1x100。.71 =26.3,p1 PQ = 0.76 x Goo-26.3) X 0.650.67】ioo中=0.76, m = 1, X = 0.672一41.94m3/s设涵洞进水口净高：h = 2.0md2.0 h A涵前水深：H= U.o /=1.92m0.87D Q 涵洞宽度：B =P:1.581xHE 1.581x1.9241.94 八八r =9.97m选一净跨径LQ = 10m的钢筋混凝
9、土盖板涵，此时涵前实际水深：(Q p(l.581xL jo7因此，进水口水深：H = 0.87H = 1.67m查表 5-8, Z ?,则涵洞净高 h Z WH = ?x 1.67 = 2.004m 牝 2.0m 6d 55(2)确定h、h、V、Vk c k c此时，临界水深=0.6435H = 1.24m k收缩断面水深：h = 0.9h = 1.12m ck(h i ( 1 92 V收缩断面流速：V。=扁=出=3.785m/sVy=6m/s临界流速：V =0.9V =3.41m/sV =6m/s kcy(3)计算临界坡度:水力半径: coR = ir =k PkBxhB + 2h kgm =.99m10 + 2x1.24= 0.304%imaxV 2GxV y 0.016x3.41)2k C2R r 4I 0.99匕 Jk k满足要求，故选取涵洞2-5.0x2.0m
