2018新规范桥涵水文计算表格

水文计算书,,,,,,,,

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一、桥位概况,,,,,,,,

河沟发源于水库，河沟总长约为14.6km。本桥所跨河沟及河滩较宽，河水较深，沟岸无坍塌现象，流速较慢，常水位较深，水深1.4～1.8m，河中少许水草，两岸阶地表层以黏土为主，下伏细砂层～卵石层。,,,,,,,,

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二、设计流量计算,,,,,,,,

流域面积,,,,F=,46.7,km2,,

主河沟长度,,,,L=,14.6,km,,

主河沟平均坡降,,,,I=,1.54‰,,,

（一）根据小流域设计暴雨洪水流量推理公式（适用于流域面积F≤500km2）,,,,,,,,

,Qp=,0.278(Sp/τn-μ)F,,,,,,

查《广西小桥涵最大一小时雨量Sp（p=1%）等值线图》得,,,,,,,,

,,,,S1%=,100.00,mm/h,,

查《广西小桥涵设计暴雨流量计算》表三,,,,丘陵区,,,,

,,,,K=,0.42,,,

,,,,α=,0.419,,,

计算得汇流时间,,,,τ=,K(L/I0.5)α,,,

,,,,=,1.18,h,,

查《广西小桥涵设计暴雨流量计算》附图五,,,,,,,,

,,,,n=,0.702,,,

计算得损失参数,,,,μ=,0.45(Sp/τn)1.05,,,

,,,,=,50.14,mm/h,,

代入公式得,,,,Q1%=,0.278(Sp/τn-μ)F,,,

,,,,=,504.8,m3/s,,

（二）设计流量取值,,,,,,,,

根据上述计算结果，取设计流量,,,,,,,,

,Q1%=,504.8,m3/s,,,,,

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三、根据设计流量推算百年一遇的设计洪水位Hs,,,,,,,,

1.采用形态法试算,,,,,,,,

,河段处洪水比降i=,0.00154,,,,,,

,假设设计水位Hs=,102.20m,，列表计算如下：,,,,,

桩号,河床高程,水深,平均水深,水面宽度,过水面积,累计面积,合计,

,(m),(m),(m),(m),(m2),(m2),,

5.34,102.20,0.00,,,,,左河滩：,

8.28,100.45,1.75,0.88,2.9,2.57,2.57,Atz=,18.10m²

10.25,100.40,1.80,1.78,2.0,3.51,6.08,Btz=,11.32m

12.22,100.35,1.85,1.83,2.0,3.60,9.68,htz=,1.60m

14.19,100.30,1.90,1.88,2.0,3.70,13.38,,

16.66,100.29,1.91,1.91,2.5,4.72,18.10,,

16.66,100.29,1.91,,,,,,

19.20,98.99,3.21,2.56,2.5,6.50,6.50,,

21.71,98.70,3.50,2.70,2.5,6.79,13.29,,

25.37,96.42,5.78,4.64,3.7,16.97,30.26,,

32.05,96.10,6.10,5.94,6.7,39.71,69.97,,

35.54,96.03,6.17,6.14,3.5,21.37,91.33,,

38.60,96.44,5.76,5.97,3.1,18.26,109.60,河槽：,

39.32,98.85,3.35,4.56,0.7,3.29,112.89,Ac=,135.04m²

42.44,99.40,2.80,3.07,3.1,9.60,122.49,Bc=,31.98m

45.54,100.18,2.03,2.41,3.1,7.47,129.96,hc=,4.22m

48.64,100.95,1.25,1.64,3.1,5.08,135.04,,

48.64,100.95,1.25,,,,,,

49.75,100.91,1.29,1.27,1.1,1.41,1.41,,

50.85,100.86,1.34,1.29,1.1,1.43,2.83,右河滩：,

51.96,100.82,1.38,1.36,1.1,1.50,4.34,Aty=,9.34m²

53.06,100.77,1.43,1.40,1.1,1.55,5.89,Bty=,8.04m

54.17,100.73,1.47,1.45,1.1,1.60,7.49,hty=,1.16m

56.68,102.20,0.00,0.73,2.5,1.85,9.34,,

查《桥位设计》表5.4.1得,,,,,,,,

,,河槽糙率系数,mc=,40,,,,

,,河滩糙率系数,mt=,25,,,,

代入公式求得,,,,,,,,

a.,河槽形态断面平均流速,,vc=,mchc2/3i1/2,,,,

,,,=,4.10,m/s,,,

,河槽形态断面流量,,Qc=,Acvc,,,,

,,,=,553.4,m3/s,,,

b.,左河滩形态断面平均流速,,vtz=,mthtz2/3i1/2,,,,

,,,=,1.34,m/s,,,

,左河滩形态断面流量,,Qtz=,Atzvtz,,,,

,,,=,24.3,m3/s,,,

c.,右河滩形态断面平均流速,,vty=,mthty2/3i1/2,,,,

,,,=,1.08,m/s,,,

,右河滩形态断面流量,,Qty=,Atyvty,,,,

,,,=,10.1,m3/s,,,

故：,全形态断面总流量,,Q=,Qc+Qtz+Qty,,,,

,,,=,587.8,m3/s,,,

,全形态断面平均流速,,v0=,Q/(Ac+Atz+Aty),,,,

,,,=,3.62,m/s,,,

,,,计算流量与设计流量误差=,(587.8-,580.0)/,580.0=,1.34%,

2.采用曼宁公式拟合流量试算,,,,,,,,

,假设设计水位Hs=,102.20m,，列表计算如下：,,,,,

河槽部分,,,,,,,,

水位,比降,糙率系数,过水断面,湿周,水面宽,水力半径,流速,流量

H,i,m,A,χ,B,R=A/χ,v=mRc2/3i1/2,Q=vA

102.20,0.0015,40.0,6.50,2.85,2.54,2.3,2.7,17.7

102.20,0.0015,40.0,6.79,2.53,2.51,2.7,3.0,20.6

102.20,0.0015,40.0,16.97,4.31,3.66,3.9,3.9,66.4

102.20,0.0015,40.0,39.71,6.69,6.69,5.9,5.1,204.1

102.20,0.0015,40.0,21.37,3.48,3.48,6.1,5.3,112.3

102.20,0.0015,40.0,18.26,3.09,3.06,5.9,5.1,93.7

102.20,0.0015,40.0,3.29,2.52,0.72,1.3,1.9,6.2

102.20,0.0015,40.0,9.60,3.17,3.12,3.0,3.3,31.5

102.20,0.0015,40.0,7.47,3.19,3.10,2.3,2.8,20.6

102.20,0.0015,40.0,5.08,3.20,3.10,1.6,2.1,10.9

,河槽流量Qc=,583.9,m3/s,,河槽平均流速vc=,4.32,m/s,

左河滩部分,,,,,,,,

水位,比降,糙率系数,过水断面,湿周,水面宽,水力半径,流速,流量

H,i,m,A,χ,B,R=A/χ,v=mRc2/3i1/2,Q=vA

102.20,0.0015,25.0,2.57,3.42,2.93,0.8,0.8,2.1

102.20,0.0015,25.0,3.51,1.97,1.97,1.8,1.4,5.0

102.20,0.0015,25.0,3.60,1.97,1.97,1.8,1.5,5.3

102.20,0.0015,25.0,3.70,1.97,1.97,1.9,1.5,5.5

102.20,0.0015,25.0,4.72,2.47,2.47,1.9,1.5,7.1

右河滩部分,,,,,,,,

水位,比降,糙率系数,过水断面,湿周,水面宽,水力半径,流速,流量

H,i,m,A,χ,B,R=A/χ,v=mRc2/3i1/2,Q=vA

102.20,0.0015,25.0,1.41,1.11,1.10,1.3,1.2,1.6

102.20,0.0015,25.0,1.43,1.11,1.10,1.3,1.2,1.7

102.20,0.0015,25.0,1.50,1.11,1.10,1.4,1.2,1.8

102.20,0.0015,25.0,1.55,1.11,1.10,1.4,1.2,1.9

102.20,0.0015,25.0,1.60,1.11,1.10,1.4,1.3,2.0

102.20,0.0015,25.0,1.85,2.91,2.52,0.6,0.7,1.3

,河滩流量Qt=,35.4,m3/s,,河滩平均流速vt=,1.29,m/s,

,全断面流量Q=Qc+Qt=,619.3,m3/s,,全断面平均流速v=,3.81,m/s,

,,计算流量与设计流量误差=,(619.3-,580.0)/,580.0=,6.78%,,

,,综上，取百年一遇设计洪水位H1%=,102.20,m，与调查历史洪水位,,101.50m,基本相符。,

四、桥孔长度计算,,,,,,,,

根据《公路工程水文勘测设计规范》（JTGC30-2015）附录A，桥位处河段为,,,,,,弯曲河段。,,

,桥孔最小净长度按下列第,,（一）,种情况的公式计算：,,,,

,（一）开阔、顺直微弯、分汊、弯曲河段及滩、槽可分的不稳定河段,,,,,,,

,,Lj=,Kq(Qp/Qc)n3Bc,,,,,

,,式中：Qp=,619.3,m3/s,,,,

,,Qc=,583.9,m3/s,,,,

,,Bc=,31.98,m,,,,

,查《公路工程水文勘测设计规范》（JTGC30-2015）表7.2.1得：,,,,,,,

,,Kq=,0.95,,,,,

,,n3=,0.87,,,,,

,则,Lj=,32.0,m,,,,

,（二）宽滩河段,,,,,,,

,,Lj=,Qp/(βQc),,,,,

,,β=,1.19(Qc/Qt)0.10,,,,,

,式中：,Qp=,619.3,m3/s,,,,

,,Qc=,583.9,m3/s,,,,

,,Qt=,35.4,m3/s,,,,

,,Bc=,31.98,m,,,,

,,qc=,Qc/Bc,,,,,

,,=,18.26,m3/s,,,,

,则,Lj=,21.5,m,,,,

,（三）滩、槽难分的不稳定河段,,,,,,,

,,Lj=,CpB0,,,,,

,,B0=,16.07(Q00.24/d00.3),,,,,

,,Cp=,(Qp/Q2%)0.33,,,,,

,式中：,Qp=,619.3,m3/s,,,,

,,Q2%=,#REF!,m3/s,,,,

,,`Q=,#REF!,m3/s,,,,

,,`d=,0.010,m,,,,

,则,Lj=,#REF!,m,,,,

,故取桥孔最小净长度,Lj=,32.0,m,,,,

,,因河流与路线方向的交角α为,90,°,,,,

,故桥长,L=Lj/cosα=,32.0,m,,,,

,,经综合考虑，桥跨布置为：,3×20m,,,,,

五、桥面高程计算,,,,,,,,

按设计洪水位计算高程,,,,,,,,

,,Hmin=,Hs+∑△h+△hj+△h0,,,,,

,式中：,,,,,,,

,,设计水位Hs=,102.20,m,,,,

,,∑△h—,壅水、浪高、水拱等总高度，一般仅考虑壅水及浪高,,,,,

,,△hj—,桥下净空安全值,,,,,

,,△h0—,建筑高度,,,,,

（一）求算∑△h,,,,,,,,

先判断桥前出现壅水或溅高,,Fr=,vc2/ghc,,,,,

,,=,0.45,<1,桥前出现壅水,,,

,故计算壅水和浪高,∑△h=,△zq+△hz,,,,,

1.求算桥前壅水高度△z和桥下壅水高度△zq,,,,,,,,

采用《桥位设计》公式13-4-1计算：,,,,,,,,

,,△z=,KNKy(vM2-voM2)/2g,,,,,

,式中：,,,,,,,

,,KN=,2/(vM/voM-1)0.5,,,,,

,,Ky=,0.5/(vM/g0.5-0.1),,,,,

,,vM=,v'M/[1+0.5d50-0.25(v'M/vc-1)],,,,,

a、求算冲刷后桥下的平均流速vM与建桥前桥孔部分的平均流速voM,,,,,,,,

,,设计流量Qs=,580.0,m3/s,,,,

,,桥下两桥台前墙间的过水面积AG=,162.47,m2,,,,

,,桥墩阻水面积Ad=,9.01,m2,,,,

,,冲刷前桥下流速v'M=,QS/(AG-Ad),,,,,

,,=,3.78,m/s,,,,

,,河床中值粒径或平均粒径d50=,20,mm,,,,

,,河槽的平均流速vc=,4.32,m/s,,,,

,于是,vM=,v'M/[1+0.5d50-0.25(v'M/vc-1)],,,,,

,,=,3.90,m/s,,,,

,,建桥前（河岸开挖后）河槽过水面积A0=,174.21,m2,,,,

,于是,v0M=,QS/A0,,,,,

,,=,3.33,m/s,,,,

b、求参数KN,,,,,,,,

,,KN=,2/(vM/voM-1)0.5,,,,,

,,=,4.85,,,,,

c、求参数Ky,,,,,,,,

,,Ky=,0.5/(vM/g0.5-0.1),,,,,

,,=,0.44,,,,,

,从而求得,△z=,KNKy(vM2-voM2)/2g,,,,,

,,=,0.44,m,,,,

桥下最大壅水高度△zq取0.5△z，,,,,,,,,

,则,△zq=,0.22,m,,,,

2.求算浪高△hz,,,,,,,,

,,△hz=,KF△hz0,,,,,

,其中：,△hz0=,0.13th[0.7(gh0/vw2)0.7]th{0.0018(gD/vw2)0.45/0.13th[0.7(gh0/vw2)0.7]}/(g/vw2),,,,,

,,KF为系数，当△hz0/h0<0.1时，取2.42；当△hz0/h0≥0.1时，取2.30,,,,,,

,,风速vw=,15,m/s,,,,

,,浪程D=,200,m,,,,

,,沿浪程平均水深h0=,1.38,m,,,,

,则,g/vw2=,0.04,/m,,,,

,,gD/vw2=,8.71,,,,,

,,gh0/vw2=,0.06,,,,,

,,计算可得△hz0=,0.10,m,,,,

,,由于△hz0/h0=,0.08,<0.1,,,,

,,应取KF=,2.42,,,,,

,,则波浪高度△hz=,KF△hz,,,,,

,,=,0.25,m,,,,

,计入桥面高程，得,∑△h=,△zq+△hz,,,,,

,,=,0.47,m,,,,

（二）确定桥下安全高度△hj,,,,,,,,

,取,△hj=,0.5,m,,,,

（三）桥梁建筑高度△h0,,,,,,,,

,,△h0=,1.40,m,,,,

因此，桥面高程计算得：,,,,,,,,

,,Hmin=,Hs+∑△h+△hj+△h0,,,,,

,,=,104.57,m,,,,

桥位处桥面高程设置为,,104.90m,~,105.15m,>,104.57m,满足要求。,

六、冲刷计算,,,,,,,,

（一）河床的一般冲刷计算,,,,,,,,

桥位处河床属黏性土河床，河槽和河滩分别按《公路工程水文勘测设计规范》（JTGC30-2015）公式8.3.2-1和8.3.2-2计算：,,,,,,,,

1.河槽部分,,,,,,,,

,,hp=,[AdQ2(hcm/hcq)5/3/(μBcj)/(0.33/IL)]5/8,,,,,

,,Q2=,QcQp/(Qc+Qtl),,,,,

,,Ad=,(Bz0.5/Hz)0.15,,,,,

,式中：,,,,,,,

,,设计流量Qp=,580.0,m3/s,,,,

,,天然状态下河槽部分设计流量Qc=,546.9,m3/s,,,,

,,天然状态下桥下河滩部分设计流量Qtl=,33.1,m3/s,,,,

,,河槽最大水深hcm=,6.17,m,,,,

,,桥下河槽平均水深hcq=,4.22,m,,,,

,,河槽部分桥孔过水净宽Bcj=,29.38,m,,,,

,,造床流量下的河槽宽度Bz=,31.98,m,,,,

,,造床流量下的河槽平均水深Hz=,4.22,m,,,,

,,冲刷坑范围内黏性土液性指数IL=,0.22,,,,,

查《公路工程水文勘测设计规范》（JTGC30-2015）表8.3.1-1得：,,,,,,,,

,,设计流速vs=,3.62,m/s,,,,

,,单孔净跨径L0=,18.7,m时，,,,,

,,桥墩水流侧向压缩系数μ=,0.931,,,,,

,,代入参数，求算得：,,,,,,

,,桥下河槽部分通过的设计流量Q2=,546.9,m3/s,,,,

,,单宽流量集中系数Ad=,1.045,,,,,

,,故桥下河槽一般冲刷后的最大水深hp=,7.70,m,,,,

2.河滩部分,,,,,,,,

,,hp=,[AdQ1(htm/htq)5/3/(μBtj)/(0.33/IL)]6/7,,,,,

,,Q1=,QtlQp/(Qc+Qtl),,,,,

,,Ad=,(Bz0.5/Hz)0.15,,,,,

,式中：,,,,,,,

,,桥下河滩最大水深htm=,1.91,m,,,,

,,桥下河滩平均水深htq=,1.38,m,,,,

,,河滩部分桥孔净长Btj=,19.36,m,,,,

,,其他参数同河槽，代入参数，求算得：,,,,,,

,,桥下河滩部分通过的设计流量Q1=,33.1,m3/s,,,,

,,故桥下河滩一般冲刷后的最大水深hp=,1.97,m,,,,

（二）桥墩局部冲刷计算,,,,,,,,

桥墩局部冲刷，按《公路工程水文勘测设计规范》（JTGC30-2015）公式8.4.2-1或8.4.2-2计算,,,,,,,,

,当hp/B1≥2.5时,,,,,,,

,,hb=,0.83KξB10.6IL1.25v,,,,,

,当hp/B1＜2.5时,,,,,,,

,,hb=,0.55KξB10.6hp0.1IL1.0v,,,,,

,式中：,,,,,,,

,,查附录C，得墩形系数Kξ=,1.00,,,,,

,,桥墩计算宽度B1=,1.30,m,,,,

,,桥下一般冲刷后的最大水深hp=,7.70,m,,,,

,,冲刷坑范围内黏性土液性指数IL=,0.22,,,,,

,v为一般冲刷后墩前行近流速，桥墩位于,,,河槽中，,用下列第,（1）,式计算：,

,,（1）河槽部分的行近流速：,,,,,,

,,v=,0.33hp3/5/IL,,,,,

,,（2）河滩部分的行近流速：,,,,,,

,,v=,0.33hp1/6/IL,,,,,

,则,v=,0.33hp3/5/IL,,,,,

,,=,5.10,m/s,,,,

,,因为hp/B1=,5.92,＞2.5,,,,

,,所以hb=,0.83KξB10.6IL1.25v,,,,,

式中Ad、Q2、Qc、Bc、λ、μ、Bcg、hcm、Vc取值同河床一般冲刷计算值，,,,,,,,,

,,hc=,ωc/Bc=,5.53m,,,,

,故：,V=,#REF!,m/s,,,,

V,#REF!,V0,#REF!,,,,,

,,n=,(V0/V)0.23+0.19lgd,,,,,

,,=,#REF!,,,,,

,,hp/B1=,5.922,≥2.5,,,,

,因此：,hb=,0.83*KξB10.6IL1.25*V,,,,,

,,=,#REF!,m,,,,

,,=,0.75,m,,,,

,,因此，桥墩最低冲刷线高程Hmin=,Hs-hp-hb,,,,,

,,=,93.75,m,,,,

（三）桥台冲刷计算,,,,,,,,

桥台局部冲刷按《公路工程水文勘测设计规范》（JTGC30-2015）公式8.4.3-1或8.4.3-2计算,,,,,,,,

,,hs＝,1.95Fr0.2Az0.5CACα,,,,,

式中：,,,,,,,,

天然河道平均流速v＝,,3.81,m/s,,,,,

天然河道平均水深h＝,,4.22,m,,,,,

弗汝德数Fr＝v2/(gh)＝,,0.35,,,,,,

桥台、路堤阻水面积Az＝,,13.00,m2,,,,,

桥台形状系数CA＝,,0.95,,,,,,

左岸桥台α＝,,90°,,,,,,

挑角系数Cα＝(α/90)0.15＝,,1.00,,,,,,

,hs＝,1.95Fr0.2Az0.5CACα,,,,,,

,＝,5.42,m,,,,,

右岸桥台α＝,,90°,,,,,,

挑角系数Cα＝(α/90)0.15＝,,1.00,,,,,,

,hs＝,1.95Fr0.2Az0.5CACα,,,,,,

,＝,5.42,m,,,,,

,,,,,,,,,

,当hp/d0≤500时,,,,,,,

,,hb=,1.17kᵋkαhp(l/hp)0.6(d0/hp)-0.15[(v-v'0)2/ghp]0.15,,,,,

,当hp/d0>500时,,,,,,,

,,hb=,1.17kᵋkαhp(l/hp)0.6(d0/hp)-0.10[(v-v'0)2/ghp]0.15,,,,,

,,,kα=(α/90)0.2,，α≤90°,,,,

,式中：,,,,,,,

,,参考表8.4.3，可得台形系数kᵋ=,0.42,,,,,

,,桥轴线与水流夹角α=,90,°,,,,

,,桥台与水流交角系数kα=,1,,,,,

,,垂直于水流流向的桥台长度l=,25.5,m,,,,

,,桥台处一般冲刷