2018新規(guī)范橋涵水文計算表格

水文計算書,,,,,,,,

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一、橋位概況,,,,,,,,

河溝發(fā)源于水庫，河溝總長約為14.6km。本橋所跨河溝及河灘較寬，河水較深，溝岸無坍塌現(xiàn)象，流速較慢，常水位較深，水深1.4～1.8m，河中少許水草，兩岸階地表層以黏土為主，下伏細(xì)砂層～卵石層。,,,,,,,,

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二、設(shè)計流量計算,,,,,,,,

流域面積,,,,F=,46.7,km2,,

主河溝長度,,,,L=,14.6,km,,

主河溝平均坡降,,,,I=,1.54‰,,,

（一）根據(jù)小流域設(shè)計暴雨洪水流量推理公式（適用于流域面積F≤500km2）,,,,,,,,

,Qp=,0.278(Sp/τn-μ)F,,,,,,

查《廣西小橋涵最大一小時雨量Sp（p=1%）等值線圖》得,,,,,,,,

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

查《廣西小橋涵設(shè)計暴雨流量計算》表三,,,,丘陵區(qū),,,,

,,,,K=,0.42,,,

,,,,α=,0.419,,,

計算得匯流時間,,,,τ=,K(L/I0.5)α,,,

,,,,=,1.18,h,,

查《廣西小橋涵設(shè)計暴雨流量計算》附圖五,,,,,,,,

,,,,n=,0.702,,,

計算得損失參數(shù),,,,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）設(shè)計流量取值,,,,,,,,

根據(jù)上述計算結(jié)果，取設(shè)計流量,,,,,,,,

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

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三、根據(jù)設(shè)計流量推算百年一遇的設(shè)計洪水位Hs,,,,,,,,

1.采用形態(tài)法試算,,,,,,,,

,河段處洪水比降i=,0.00154,,,,,,

,假設(shè)設(shè)計水位Hs=,102.20m,，列表計算如下：,,,,,

樁號,河床高程,水深,平均水深,水面寬度,過水面積,累計面積,合計,

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

5.34,102.20,0.00,,,,,左河灘：,

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,右河灘：,

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《橋位設(shè)計》表5.4.1得,,,,,,,,

,,河槽糙率系數(shù),mc=,40,,,,

,,河灘糙率系數(shù),mt=,25,,,,

代入公式求得,,,,,,,,

a.,河槽形態(tài)斷面平均流速,,vc=,mchc2/3i1/2,,,,

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

,河槽形態(tài)斷面流量,,Qc=,Acvc,,,,

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

b.,左河灘形態(tài)斷面平均流速,,vtz=,mthtz2/3i1/2,,,,

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

,左河灘形態(tài)斷面流量,,Qtz=,Atzvtz,,,,

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

c.,右河灘形態(tài)斷面平均流速,,vty=,mthty2/3i1/2,,,,

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

,右河灘形態(tài)斷面流量,,Qty=,Atyvty,,,,

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

故：,全形態(tài)斷面總流量,,Q=,Qc+Qtz+Qty,,,,

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

,全形態(tài)斷面平均流速,,v0=,Q/(Ac+Atz+Aty),,,,

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

,,,計算流量與設(shè)計流量誤差=,(587.8-,580.0)/,580.0=,1.34%,

2.采用曼寧公式擬合流量試算,,,,,,,,

,假設(shè)設(shè)計水位Hs=,102.20m,，列表計算如下：,,,,,

河槽部分,,,,,,,,

水位,比降,糙率系數(shù),過水?dāng)嗝?濕周,水面寬,水力半徑,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,

左河灘部分,,,,,,,,

水位,比降,糙率系數(shù),過水?dāng)嗝?濕周,水面寬,水力半徑,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

右河灘部分,,,,,,,,

水位,比降,糙率系數(shù),過水?dāng)嗝?濕周,水面寬,水力半徑,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

,河灘流量Qt=,35.4,m3/s,,河灘平均流速vt=,1.29,m/s,

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

,,計算流量與設(shè)計流量誤差=,(619.3-,580.0)/,580.0=,6.78%,,

,,綜上，取百年一遇設(shè)計洪水位H1%=,102.20,m，與調(diào)查歷史洪水位,,101.50m,基本相符。,

四、橋孔長度計算,,,,,,,,

根據(jù)《公路工程水文勘測設(shè)計規(guī)范》（JTGC30-2015）附錄A，橋位處河段為,,,,,,彎曲河段。,,

,橋孔最小凈長度按下列第,,（一）,種情況的公式計算：,,,,

,（一）開闊、順直微彎、分汊、彎曲河段及灘、槽可分的不穩(wěn)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《公路工程水文勘測設(shè)計規(guī)范》（JTGC30-2015）表7.2.1得：,,,,,,,

,,Kq=,0.95,,,,,

,,n3=,0.87,,,,,

,則,Lj=,32.0,m,,,,

,（二）寬灘河段,,,,,,,

,,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,,,,

,則,Lj=,21.5,m,,,,

,（三）灘、槽難分的不穩(wěn)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,,,,

,則,Lj=,#REF!,m,,,,

,故取橋孔最小凈長度,Lj=,32.0,m,,,,

,,因河流與路線方向的交角α為,90,°,,,,

,故橋長,L=Lj/cosα=,32.0,m,,,,

,,經(jīng)綜合考慮，橋跨布置為：,3×20m,,,,,

五、橋面高程計算,,,,,,,,

按設(shè)計洪水位計算高程,,,,,,,,

,,Hmin=,Hs+∑△h+△hj+△h0,,,,,

,式中：,,,,,,,

,,設(shè)計水位Hs=,102.20,m,,,,

,,∑△h—,壅水、浪高、水拱等總高度，一般僅考慮壅水及浪高,,,,,

,,△hj—,橋下凈空安全值,,,,,

,,△h0—,建筑高度,,,,,

（一）求算∑△h,,,,,,,,

先判斷橋前出現(xiàn)壅水或濺高,,Fr=,vc2/ghc,,,,,

,,=,0.45,<1,橋前出現(xiàn)壅水,,,

,故計算壅水和浪高,∑△h=,△zq+△hz,,,,,

1.求算橋前壅水高度△z和橋下壅水高度△zq,,,,,,,,

采用《橋位設(shè)計》公式13-4-1計算：,,,,,,,,

,,△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、求算沖刷后橋下的平均流速vM與建橋前橋孔部分的平均流速voM,,,,,,,,

,,設(shè)計流量Qs=,580.0,m3/s,,,,

,,橋下兩橋臺前墻間的過水面積AG=,162.47,m2,,,,

,,橋墩阻水面積Ad=,9.01,m2,,,,

,,沖刷前橋下流速v'M=,QS/(AG-Ad),,,,,

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

,,河床中值粒徑或平均粒徑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,,,,

,,建橋前（河岸開挖后）河槽過水面積A0=,174.21,m2,,,,

,于是,v0M=,QS/A0,,,,,

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

b、求參數(shù)KN,,,,,,,,

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

,,=,4.85,,,,,

c、求參數(shù)Ky,,,,,,,,

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

,,=,0.44,,,,,

,從而求得,△z=,KNKy(vM2-voM2)/2g,,,,,

,,=,0.44,m,,,,

橋下最大壅水高度△zq取0.5△z，,,,,,,,,

,則,△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為系數(shù)，當(dāng)△hz0/h0<0.1時，取2.42；當(dāng)△hz0/h0≥0.1時，取2.30,,,,,,

,,風(fēng)速vw=,15,m/s,,,,

,,浪程D=,200,m,,,,

,,沿浪程平均水深h0=,1.38,m,,,,

,則,g/vw2=,0.04,/m,,,,

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

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

,,計算可得△hz0=,0.10,m,,,,

,,由于△hz0/h0=,0.08,<0.1,,,,

,,應(yīng)取KF=,2.42,,,,,

,,則波浪高度△hz=,KF△hz,,,,,

,,=,0.25,m,,,,

,計入橋面高程，得,∑△h=,△zq+△hz,,,,,

,,=,0.47,m,,,,

（二）確定橋下安全高度△hj,,,,,,,,

,取,△hj=,0.5,m,,,,

（三）橋梁建筑高度△h0,,,,,,,,

,,△h0=,1.40,m,,,,

因此，橋面高程計算得：,,,,,,,,

,,Hmin=,Hs+∑△h+△hj+△h0,,,,,

,,=,104.57,m,,,,

橋位處橋面高程設(shè)置為,,104.90m,~,105.15m,>,104.57m,滿足要求。,

六、沖刷計算,,,,,,,,

（一）河床的一般沖刷計算,,,,,,,,

橋位處河床屬黏性土河床，河槽和河灘分別按《公路工程水文勘測設(shè)計規(guī)范》（JTGC30-2015）公式8.3.2-1和8.3.2-2計算：,,,,,,,,

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：,,,,,,,

,,設(shè)計流量Qp=,580.0,m3/s,,,,

,,天然狀態(tài)下河槽部分設(shè)計流量Qc=,546.9,m3/s,,,,

,,天然狀態(tài)下橋下河灘部分設(shè)計流量Qtl=,33.1,m3/s,,,,

,,河槽最大水深hcm=,6.17,m,,,,

,,橋下河槽平均水深hcq=,4.22,m,,,,

,,河槽部分橋孔過水凈寬Bcj=,29.38,m,,,,

,,造床流量下的河槽寬度Bz=,31.98,m,,,,

,,造床流量下的河槽平均水深Hz=,4.22,m,,,,

,,沖刷坑范圍內(nèi)黏性土液性指數(shù)IL=,0.22,,,,,

查《公路工程水文勘測設(shè)計規(guī)范》（JTGC30-2015）表8.3.1-1得：,,,,,,,,

,,設(shè)計流速vs=,3.62,m/s,,,,

,,單孔凈跨徑L0=,18.7,m時，,,,,

,,橋墩水流側(cè)向壓縮系數(shù)μ=,0.931,,,,,

,,代入?yún)?shù)，求算得：,,,,,,

,,橋下河槽部分通過的設(shè)計流量Q2=,546.9,m3/s,,,,

,,單寬流量集中系數(shù)Ad=,1.045,,,,,

,,故橋下河槽一般沖刷后的最大水深hp=,7.70,m,,,,

2.河灘部分,,,,,,,,

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

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

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

,式中：,,,,,,,

,,橋下河灘最大水深htm=,1.91,m,,,,

,,橋下河灘平均水深htq=,1.38,m,,,,

,,河灘部分橋孔凈長Btj=,19.36,m,,,,

,,其他參數(shù)同河槽，代入?yún)?shù)，求算得：,,,,,,

,,橋下河灘部分通過的設(shè)計流量Q1=,33.1,m3/s,,,,

,,故橋下河灘一般沖刷后的最大水深hp=,1.97,m,,,,

（二）橋墩局部沖刷計算,,,,,,,,

橋墩局部沖刷，按《公路工程水文勘測設(shè)計規(guī)范》（JTGC30-2015）公式8.4.2-1或8.4.2-2計算,,,,,,,,

,當(dāng)hp/B1≥2.5時,,,,,,,

,,hb=,0.83KξB10.6IL1.25v,,,,,

,當(dāng)hp/B1＜2.5時,,,,,,,

,,hb=,0.55KξB10.6hp0.1IL1.0v,,,,,

,式中：,,,,,,,

,,查附錄C，得墩形系數(shù)Kξ=,1.00,,,,,

,,橋墩計算寬度B1=,1.30,m,,,,

,,橋下一般沖刷后的最大水深hp=,7.70,m,,,,

,,沖刷坑范圍內(nèi)黏性土液性指數(shù)IL=,0.22,,,,,

,v為一般沖刷后墩前行近流速，橋墩位于,,,河槽中，,用下列第,（1）,式計算：,

,,（1）河槽部分的行近流速：,,,,,,

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

,,（2）河灘部分的行近流速：,,,,,,

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

,則,v=,0.33hp3/5/IL,,,,,

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

,,因為hp/B1=,5.92,＞2.5,,,,

,,所以hb=,0.83KξB10.6IL1.25v,,,,,

式中Ad、Q2、Qc、Bc、λ、μ、Bcg、hcm、Vc取值同河床一般沖刷計算值，,,,,,,,,

,,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，橋墩最低沖刷線高程Hmin=,Hs-hp-hb,,,,,

,,=,93.75,m,,,,

（三）橋臺沖刷計算,,,,,,,,

橋臺局部沖刷按《公路工程水文勘測設(shè)計規(guī)范》（JTGC30-2015）公式8.4.3-1或8.4.3-2計算,,,,,,,,

,,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,,,,,

弗汝德數(shù)Fr＝v2/(gh)＝,,0.35,,,,,,

橋臺、路堤阻水面積Az＝,,13.00,m2,,,,,

橋臺形狀系數(shù)CA＝,,0.95,,,,,,

左岸橋臺α＝,,90°,,,,,,

挑角系數(shù)Cα＝(α/90)0.15＝,,1.00,,,,,,

,hs＝,1.95Fr0.2Az0.5CACα,,,,,,

,＝,5.42,m,,,,,

右岸橋臺α＝,,90°,,,,,,

挑角系數(shù)Cα＝(α/90)0.15＝,,1.00,,,,,,

,hs＝,1.95Fr0.2Az0.5CACα,,,,,,

,＝,5.42,m,,,,,

,,,,,,,,,

,當(dāng)hp/d0≤500時,,,,,,,

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

,當(dāng)hp/d0>500時,,,,,,,

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

,,,kα=(α/90)0.2,，α≤90°,,,,

,式中：,,,,,,,

,,參考表8.4.3，可得臺形系數(shù)k?=,0.42,,,,,

,,橋軸線與水流夾角α=,90,°,,,,

,,橋臺與水流交角系數(shù)kα=,1,,,,,

,,垂直于水流流向的橋臺長度l=,25.5,m,,,,

,,橋臺處一般沖刷