跌水水力计算(水工结构版)

1、矩形断面多级跌水水力计算第 1 页，共 3 页矩矩形形断断面面多多级级跌跌水水水水力力计计算算（跌跌水水高高度度大大于于3m3m宜宜采采用用多多级级跌跌水水）跌跌水水截截洪洪沟沟设设计计流流量量 Q=Q=26.30026.300m m截截洪洪沟沟跌跌水水段段宽宽度度 b=b=2.7002.700m m水水 深深 h=h=3.1653.165m m每每级级跌跌水水跌跌差差P Pn= =2.0002.000m m1 1）跌跌水水口口计计算算。采采用用无无底底槛槛矩矩形形跌跌水水口口；=0.9000.900(侧收缩系数，一般采用0.850.95）M=1.6201.620(无底槛宽顶堰的第二流量系数，

2、一般取1.62）堰堰上上水水头头 H H0= = (Q/Mb)(Q/Mb)2/3= =3.5473.547m m2)2)、计计算算第第一一级级跌跌水水：T T01= =P P1+H+H0= =5.5475.547m mq qQ/bQ/b = =9.7419.741m m3/(s.m)/(s.m)q q2/3/ /T T010 0. .8 82 22 2根根据据跌跌水水高高度度选选择择流流速速系系数数0.9000.900根根据据、q q2/3/T/T01值值差差附附录录2020得得：h h1/q/q2/3= =0.2550.255h h2/q/q2/3= =0.7750.775h h1= =1.

3、1631.163m mh h2= =3.5353.535m mh2h1,h2h1,采采用用降降低低渠渠底底形形成成消消力力池池第第一一级级消消力力槛槛上上的的水水头头H H01: :H H01= =(q/M)(q/M)2/3= =3.0163.016m m消消力力槛槛前前的的行行进进流流速速v01：v01q/hq/h2= =2.7562.756m/sm/s消消力力槛槛上上水水深深 H H1: :1.0501.050（流速系数，一般采用1.05）H H1H H01-v201/2g/2g = =2.6092.609m m初初步步确确定定消消力力槛槛高高度度C C1= =d d1: :1.0501.

4、050（保证水跃淹没的安全系数，一般采用1.051.10）C C1= =hh2-H-H1= =1.1021.102m m采采用用消消力力槛槛高高度度C C11.2001.200m m验验算算第第一一级级消消力力池池的的深深度度：TT01= =T T01+C+C1= =6.7476.747m mq q2/3/T/T010 0. .6 67 76 6并并根根据据0.900.90查查附附录录2020得得：hh01/q/q2/3= =0.2230.223hh01= =1.0171.017m m消消力力池池中中收收缩缩断断面面的的流流速速v1: :V V1= =q/hq/h01= =9.5779.577

5、m/sm/s消消力力槛槛顶顶的的流流速速V V2: :V V2= =(M(M2q)q)1/3= =3.2303.230m/sm/s壅壅高高水水跃跃的的第第二二共共轭轭水水深深hh02: :hh02= =(h(h01) )2+0.205q(V+0.205q(V1-V-V2)1/2= =3.7023.702m mv02= =q/hq/h02= =2.6312.631m/sm/sHH1= =H H01-v 202/2g/2g = =2.6452.645m mCC1= = hh02- - HH1= =1.2421.242m mC1C1,C1C1,采采用用C1C1 1.201.20m m第第一一级级消消

6、力力池池长长度度计计算算：L Lc1=L=L1+0.8L+0.8L2L L1=1.64(H=1.64(H0(P+d+0.24H(P+d+0.24H0)1/26.2176.217m mF Fr= =v1/(gh/(gh01) )1/2= =3.0323.032m m根根据据1.7Fr91.7h1,h2h1,采采用用降降低低渠渠底底形形成成消消力力池池第第二二级级消消力力槛槛上上的的水水头头H H02: :H H02= =(q/M)(q/M)2/3= =3.0163.016m m消消力力槛槛前前的的行行进进流流速速v01：v02q/hq/h2= =2.9342.934m/sm/s消消力力槛槛上上水

7、水深深 H H2: :H H2H H02-v202/2g/2g = =2.5552.555m m初初步步确确定定消消力力槛槛高高度度C C2= =d d2: :C C2= =hh2-H-H2= =0.9310.931m m采采用用消消力力槛槛高高度度C C21.1001.100m m验验算算第第二二级级消消力力池池的的深深度度：TT02= =T T02+C+C2= =6.1166.116m mq q2/3/T/T020 0. .7 74 46 6并并根根据据 0 0. .9 90 0查查附附录录2020得得：hh01/q/q2/3= =0.2350.235hh01= =1.0721.072m

8、m消消力力池池中中收收缩缩断断面面的的流流速速v1: :V V1= =q/hq/h01= =9.0889.088m/sm/s消消力力槛槛顶顶的的流流速速V V2: :V V2= =(M(M2q)q)1/3= =3 3. .2 23 30 0壅壅高高水水跃跃的的第第二二共共轭轭水水深深hh02: :hh02=(h=(h01) )2+0.205q(V+0.205q(V1-V-V2)1/2= =3.5843.584m mv02= =q/hq/h02= =2.7182.718m/sm/sHH2= =H H02-v 202/2g/2g = =2.6202.620m mCC2= = hh02- - HH2

9、= =1.1431.143m mC1C1,C1C1,采采用用C1C1 1 1. .1 10 0m m第第二二级级消消力力池池长长度度计计算算：L Lc2=L=L1+0.8L+0.8L2L L1=1.64(H=1.64(H01(P+d+0.24H(P+d+0.24H01)1/25.5695.569m mF Fr= =v1/(gh/(gh01) )1/2= =2.8032.803根根据据1.7Fr91.7ht,h02ht,采采用用降降低低渠渠底底形形成成消消力力池池初初步步确确定定消消力力池池深深d d3: :d d3= =hh02-H-Ht= =0.2860.286m m采采用用消消力力池池深深

10、度度d d30.5000.500m m验验算算第第三三级级消消力力池池的的深深度度：TT03=P=P3+H+H02+d+d3= =5 5. .5 51 16 6m mq q2/3/T/T030 0. .8 82 27 7并并根根据据0.900.90查查附附录录2020得得：hh01/q/q2/3= =0.2550.255hh02/q/q2/3= =0.7750.775hh01= =1 1. .1 16 63 3hh02= =3.5353.535消消力力池池中中收收缩缩断断面面的的流流速速v1: :V V1= =q/hq/h01= =8.3748.374m/sm/s消消力力槛槛顶顶的的流流速速v

11、2：V V2= =(M(M2q)q)1/3= =3.2303.230m/sm/s壅壅高高水水跃跃的的第第二二共共轭轭水水深深hh02: :hh02=(h=(h01) )2+0.205q(V+0.205q(V1-V-V2)1/2= =3.4103.410m md d3= = hh02- - H Ht= =0.3800.380m m采采用用消消力力池池深深度度d d30.5000.500m m第第三三级级消消力力池池长长度度计计算算：L Lc3=L=L1+0.8L+0.8L2L L1=1.64(H=1.64(H02(P+d+0.24H(P+d+0.24H02)1/25.1145.114m mF Fr=v=v1/(gh/(gh01) )1/2= =2.4792.479根根据据1.7Fr91.7Fr9时时， L2=9.5h01(Fr-1)=L2=9.5h01(Fr-1)=16.34516.3