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012mmmmmmmmmm3采用双圆弧、三圆弧或椭圆曲线。(3)简图如下:(1)根据规范2.3.3条,控制堰的型式应根据地形、地质条件、水利条件、运用要求,通过技术经济综合比较选定。堰型可选用开敞式或带胸墙孔口式的实用堰、宽顶堰、驼峰堰等型式。开敞式溢流堰有较大的超泄能力,宜优先选用。本工程选用开敞式实用堰。(2)按规范3.3.1条,采用开敞式实用堰时,堰顶下游堰面宜优先采用WES型幂曲线,堰顶上游堰头可本工程下游堰面选用WES幂曲线(按附录A.1.1-1式),上游堰头为三圆弧,上游面铅直。0校核流量下的堰上水头Hmax=3.26上游堰高P1=40堰面曲线选择m³/s设计堰顶高程Z4=700上游引渠底板高程Z5=660与堰下游反弧面相接的泄槽纵坡i=0.005溢流堰共分1孔,中墩厚度d=消能防冲标准水位(P=5%)Z3=662.49消能防冲标准下泄流量Q消=53.1m³/s上游设计洪水位(P=3%)Z2=702.19设计洪水标准下泄流量Q设=61.7m³/s上游校核洪水位(P=0.33%)Z1=703.26校核洪水标准下泄流量Q校=112《溢洪道设计规范》(SL253-2000)基本资料建筑物级别:4级溢流堰净宽B=10堰后泄槽宽B泄=10石景山溢洪道工程WES堰计算书工程名称:石景山溢洪道工程计算时间:2015年6月2日设计依据3.1mm3.23.33.4mHd28.43635.75538.436反弧低点(C)高程Z6=661.5640.7510.0000.00500027.80534.43635.805反弧曲面末端端点C及其圆心O2点坐标计算表mRiXbYbXoYoXcYc式中:m…幂曲线末端切线坡率(或直线段坡率),m=0.75R反弧半径,根据规范3.3.8条,取4~10倍反弧最低点最大水深,流速大时取大值,初取R=10.000i…与反弧面相接的泄槽纵坡,本工程i=0.005000②反弧末端C点坐标(Xc,Yc)及圆心O2点坐标(Xo,Yo)按下式计算:Xo=Xb+Rsin[ATAN(1/m)]Yo=Yb-Rcos[ATAN(1/m)]Xc=Xo-Rsin[ASIN(i)]Yc=Yo+Rcos[ASIN(i)]Xb=27.805Yb=34.436B点高程=665.564设计幂曲线末端接直线段即L1=23.5m,则B点座标为:0.112溢流堰幂曲线下游特征点坐标计算①计算简图中B点坐标(Xb,Yb)按下式计算:Xb=Xa+L1Yb=Ya+L1/m式中:L1为A、B点间水平距离2.8-0.4901.400-0.7730.560-0.790第一段圆弧第二段圆弧第三段圆弧X1=-0.175HdR1=0.5HdX1=-0.276HdR1=0.2HdX1=-0.282HdR1=0.04Hd2.0532.3812.7313.103上游堰面三圆弧曲线计算堰顶O点上游三圆弧半径R及端点X坐标计算表0.5700.7580.9701.2061.4651.7483.7314.0184.305Y00.0210.0750.1580.2690.4072.0092.2962.5832.873.1573.444696.897堰顶下游幂曲线坐标表(取15个点)X00.2870.5740.8611.1481.4351.722由1/m=dy/dx得幂曲线末端点A点坐标:Xa=4.305Ya=3.103A点高程=幂曲线末端端点计算设计幂曲线末端端点切线坡率m=0.75对堰面幂曲线一阶求导得:dy/dx=0.385529314497921x^0.85由于上游堰面铅直,即△y╱△x=3∶0,故取n=1.850将数据代入,即得下游堰面曲线方程:x1.85=4.79859748774039y1.33Hd=3.724<上游堰高P1=40,因此溢流堰为高堰P1/Hd=14.286>1.0,取k=2下游堰面曲线计算取堰面曲线定型设计水头Hd=0.85Hmax=2.8高堰ykHxndn1i><4Ak=Bkhkχk=Bk+2hkRk=Ak/χkB…溢流堰总净宽,m,B=nbb…单孔宽度,mn…闸孔数目泄流能力校核开敞WES型实用堰的泄流能力按规范A.2.1-1式计算:Q=cmεσεsB√2gH03/2ε=1-0.2[ξK+(n-1)ξ0]H0/nb(适用于H0/b≤1.0,当H0/b>1.0时,H0/b仍取值1.0)式中:Q…流量,m³/s0.206计算断面流速v1=q/h1=25.742m³/s反弧半径R应为h1的4~10倍,即0.825m~2.06m复核初取R值q/φ√2g(H0-h1cosθ)0.2060.2060.2060.206h1=h12.0000.2060.2060.206试算完成!m³/s,H0=41.7mθ…泄槽底坡坡角,cosθ=0.004999938φ…计算断面流速系数,取0.9h1试算表h1反弧段最低点水深h1=q/φ√2g(H0-h1cosθ)式中:q…计算断面单宽流量,m³/s.mH0…计算断面渠底以上总水头,H0=H+v²/g,本工程行近流速v=067.8071.4220.00274ik,反弧低点收缩断面水深h1hk,均匀急流。Ckhkik53.1105.310.01514.2212.8441.107n…糙率,可按表A.7查取,本工程取n=0.015临界底坡ik和临界水深hk计算表QBkqnAkχkRkg…重力加速度,g=9.81Bk…泄槽宽度,mAk…临界水深断面面积,m²χk…临界水深断面湿周,m;Rk…临界水深断面水力半径,mCk…谢才系数;③反弧半径R复核:堰后泄槽为矩形断面,反弧低点临界水深hk及临界底坡ik按下式求取:式中:q…泄槽单宽流量,m³/s.mα…动能修正系数,取1反弧圆心O2点高程=671.56423kqhg6/11kkRnCkkkkBCgi228.310xR648.11162128.3HHvx10.5021.0573.35满足泄流要求Q结论1101002.190.70.9693ξ0ξKεcmσs0.5021.05131.15满足泄流要求设计洪水标准(P=3%)下泄流量计算表nbBvH0结论1101003.2600.70.95441ξKεcmσsQnbBvH0ξ0c…上游堰坡影响系数(上游堰坡铅直时c=1.0;上游堰坡倾斜时,由规范表A2.1.1-2查得)ε…闸墩侧收缩系数ξ0…中墩形状系数,查规范表A.2.1-3ξK…边墩形状系数,如图A.2.1-2,对于直角矩形ξK=1.0;折线或圆角形ξK=0.7;流线形ξK=0.4σs…淹没系数,查规范图A.2.1-3,不淹没时σs=1.05,下游稍有淹没校核洪水标准(P=0.33%)下泄流量计算表H0…计入行近流速的堰上总水头,m,H0=H+v²/2gg…重力加速度,m/s²m…二维水流WES实用堰流量系数,由规范表A2.1.1-1查得上游堰高P1(m)40定型设计水头Hd(m)2.8a0.28aHd0.784b0.16374269bHd0.458479532堰顶上游曲线坐标X00.10.2Y00.0040.014一、基本参数二、堰顶上游曲线确定1、椭圆弧曲线P1/Hd14.28571429属于高堰取aHd值0.8取bHd值0.450.30.40.50.60.0330.060.0990.152一、基本参数二、堰顶上游曲线确定1、椭圆弧曲线水工设计手册第二版注:所有情况的坐标原点均为堰顶,注意与低坝的区别。坝头部曲线段水面线X/HY/HHXY-1-1.0709004333.26-3.26-3.49-0.8-1.0494155843.26-2.61-3.42-0.6-1.0214415583.26-1.96-3.33-0.4-0.9869696973.26-1.30-3.22-0.2-0.9399826843.26-0.65-3.060-0.8769696973.260.00-2.860.2-0.7994848483.260.65-2.610.4-0.7029913423.261.30-2.290.6-0.5844805193.261.96-1.910.8-0.4439610393.262.61-1.451-0.2774242423.263.26-0.901.2-0.0819047623.263.91-0.271.40.1466406933.264.560.481.60.4036926413.265.221.321.80.6947056283.265.872.27基本数据校核水位703.26下泄流量Q53.1计算点坐标Xi计算点坐标Yi堰顶高程700堰顶宽度b1033.4541.96堰上水头Hmax3.26单宽流量q5.310.75Hmax2.445夹角α53.130.95Hmax3.097cosa0.600所以Hd=2.8sina0.800下游坡比m=0.75流速系数ψ0.95切点坐标Xt4.31切点坐标Yt3.10曲线段总长度Lct6.3558堰顶上游曲线段长度Lcu0.882堰顶下游曲线段长度Lcd5.4738坝面任一点直线段长度Lsi48.57坝顶起点到(Xi,Yi)的坝面距离L54.048掺气起点位置Lk42.003无中墩时的水面曲线坐标cadPlinecoordinateH/Hd0.511.33X,YX/Hd-3.26,-3.491-1-0.49-0.933-1.21-2.608,-3.421-0.8-0.484-0.915-1.185-1.956,-3.33-0.6-0.475-0.893-1.151-1.304,-3.218-0.4-0.46-0.865-1.11-0.652,-3.064-0.2-0.425-0.821-1.060,-2.8590-0.371-0.755-10.652,-2.6060.2-0.3-0.681-0.9191.304,-2.2920.4-0.2-0.586-0.8211.956,-1.9050.6-0.075-0.465-0.7052.608,-1.4470.80.075-0.32-0.5693.26,-0.90410.258-0.145-0.4113.912,-0.2671.20.470.055-0.224.564,0.4781.40.7050.294-0.0025.216,1.3161.60.9720.5630.2435.868,2.2651.81.2690.8570.531hpq/φ√2g(H0-hpcosθ)坝面距离边界层δ假设势流水深hp试算势流水深hp54.051.62010.1890.1880.188Y/Hd1.16Y1/Hd-1.071-1.049-1.021-0.987-0.940-0.877-0.799-0.703-0.584-0.444-0.277-0.0820.1470.4040.695水力半径R0.43766258掺气的临界Vk0.004228774H+Yi=αVi^2/2g0.5-1.5m正交于坝面的水深h自然掺气水深hb对应点流速v安全超高边墙高0.4800.67529.06811.67511.07063422坝头曲线段水面线坐标(适用于低坝)堰顶水头HX/HY/HXYX,Y-2.400.989-7.8243.224-7.824,3.224-2.200.986-7.1723.214-7.172,3.214-2.000.984-6.523.208-6.52,3.208-1.800.98-5.8683.195-5.868,3.195-1.600.975-5.2163.178-5.216,3.178-1.400.969-4.5643.159-4.564,3.159-1.200.961-3.9123.133-3.912,3.133-1.000.951-3.263.1-3.26,3.1-0.800.938-2.6083.058-2.608,3.058-0.600.921-1.9563.002-1.956,3.002-0.400.898-1.3042.927-1.304,2.927
本文标题:溢流坝段计算表格
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