某水電站工程隧洞水力計(jì)算過程案例目錄TOC\o"1-3"\h\u14867某水電站工程隧洞水力計(jì)算過程案例 168551.1水流流態(tài)判別 1107881.1.1半有壓流下限流量計(jì)算 1143521.1.2半有壓流與有壓流的臨界流量計(jì)算 2104821.2陡緩坡判別 3231201.3泄流能力計(jì)算結(jié)果 4323471.3.1無壓流泄流能力計(jì)算結(jié)果 4238631.3.2有壓流泄流能力計(jì)算結(jié)果 6177551.4調(diào)洪演算 735121.4.1設(shè)計(jì)洪水過程線等別確定 7177771.4.2小結(jié) 7292591.4.3確定設(shè)計(jì)調(diào)洪的起始條件 972661.4.4設(shè)計(jì)洪水的演算 9經(jīng)比較，選定的方案為11*11m(寬*高)上圓下方城門洞型隧洞進(jìn)行導(dǎo)流。1.1水流流態(tài)判別施工中的隧洞泄流也屬于管道泄流，當(dāng)水流通過管道具有自由表面時(shí)為明流，即無壓流;當(dāng)管道進(jìn)口封閉而管身水流仍保持自由表面時(shí)為半有壓流:若進(jìn)口封閉，管身充滿水流時(shí)為有壓流。1.1.1半有壓流下限流量計(jì)算根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第一卷499頁:Qpc式中τpc——半有壓流的下限臨界壅高比，此處取1.10:μ——流量系數(shù)，此進(jìn)口為潛沒側(cè)墻的喇叭式，根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第一卷516頁表2-5-32，此處=0.670;ε——進(jìn)口豎向收縮系數(shù)，，根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第一卷516頁表2-5-32，此處=0.740;Ad——管道斷而面積，A=108.02m2d——管身高度，d=11m計(jì)算得：Q1.1.2半有壓流與有壓流的臨界流量計(jì)算根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第-卷500頁：QFc式中Cd——管道的謝才系數(shù)，由前面可知Cd=59.182；Rd——管道的水力半徑，由的面可知Rd=2.75；∑ζ——局部損失系數(shù)，由前而可知∑ζ=0.414；η——有壓流出口水頭比,因出口為大氣中射流《水利水電工程施工組織設(shè)計(jì)手冊》第一卷517頁表2-5-33，此處η=0.50;τpc——半有壓流與有壓流分界點(diǎn)的上游臨界壅高比，此處采用經(jīng)驗(yàn)值τpc=1.5；計(jì)算得:Q通過計(jì)算可知，結(jié)合紅水電站來水情況。隧洞先是無壓流態(tài)。再是半有壓流態(tài)，最后再到有壓流態(tài)。1.2陡緩坡判別當(dāng)隧洞水流為無壓流態(tài)時(shí)，由《水力計(jì)算手冊》第36頁：i式中Ck——水深為hk時(shí)的謝才系數(shù)；Bk——水深為hk時(shí)的水面寬；χk——水深為hk時(shí)的濕周；α——?jiǎng)幽苄拚禂?shù)，此處取1.05;hk——臨界水深，滿足條件1?計(jì)算結(jié)果如表4-1：表3-1陡緩坡計(jì)算表Q(m3/s)gB(m)hkχ(m)nR(m)Cik209.8110.70812.4160.020.62746.2610.00492409.8111.12311.2460.020.93349.4220.00460609.8111.47211.9440.021.16151.2610.00450809.8111.78314.5660.021.34652.5420.004481009.8112.06915.1380.021.50351.5160.004481209.8112.33615.6720.021.64054.2950.004511409.8112.58916.1780.021.76054.9420.004551609.8112.83016.6600.021.86955.4910.004591809.8111.06117.1220.021.96755.9650.004642009.8111.28417.5680.022.05656.3830.004692209.8111.50018.0000.022.13956.7550.004742409.8111.70918.4180.022.21557.0870.004802609.8111.91218.8240.022.28657.3870.004852809.8114.11019.2200.022.35257.6610.004903009.8114.30319.6060.022.41457.9120.004963209.8114.49319.9860.022.47358.1440.005023409.8114.67820.3560.022.52858.3580.005073609.8114.86020.7200.022.58058.5570.005133809.8115.03821.0760.022.62958.7420.005184009.8115.21321.4260.022.67658.9150.005244209.8115.38521.7700.022.72159.0780.005294409.8115.55522.1100.022.76459.2310.005354609.8115.72222.4440.022.80459.3760.005404809.8115.88722.7740.022.84359.5130.005465009.8116.04921.0980.022.88159.6420.005515209.8116.21021.4200.022.91759.7660.005565409.8116.36821.7360.022.95159.8830.005625609.8116.52424.0480.022.98459.9940.005675809.8116.67824.3560.021.01660.1000.005726009.8116.83124.6620.021.04760.2020.005776109.8116.90724.8140.021.06260.2510.005806209.8116.98224.9640.021.07760.2990.005836309.8117.05725.1140.021.09160.3470.00585637.619.8117.11425.2280.021.10260.3820.00587因隧洞底坡i=6.23%>ik=5.87%，為陡坡。1.3泄流能力計(jì)算結(jié)果1.1.1無壓流泄流能力計(jì)算結(jié)果經(jīng)過緩陡坡計(jì)算，得出該隧洞為陡坡。因此管道長度對泄流沒有影響，故本次泄流量按短管計(jì)算。根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第一卷503頁,短管泄流量非淹沒寬項(xiàng)堰公式:Q式中m——流量系數(shù)，mA——上游壅高水深處斷面面積，m2;AH——水深H與B的乘積;m0——進(jìn)口系數(shù)；可查《水利水電工程施工組織設(shè)計(jì)手冊》第一卷504頁表2-5-22。此處取m0=0.360。表3-2無壓流水位流量關(guān)系表Z(m)H(m)Bk(m)H/dm0mAHH0AQ(m3/s)48801100.360.360000.004891110.0909090.360.379111.112.118.464902110.1818180.360.379222.224.252.204913110.2727270.360.379331.336.395.914924110.3636360.360.379444.448.4147.664935110.4545450.360.379555.560.5206.354946110.5454550.360.37965.996.672.6271.264957110.6363640.3350.37376.797.784.7336.424968110.7272730.3350.37287.028.896.8409.924979110.8181820.3350.37196.219.9108.9487.8249810110.9090910.3350.368101.7111121566.72499111110.3350.364108.0212.1131.1646.71根據(jù)無壓流水位流量關(guān)系繪出水位-流量關(guān)系圖：圖3-1無壓流水位-流量關(guān)系圖1.1.2有壓流泄流能力計(jì)算結(jié)果根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第一卷516頁有壓流公式:Q式中μ——流量系數(shù):；ω——隧洞出口斷面面積；T0——上游水面與隨洞出口底板高程差及上游行近流速水頭之和，這里認(rèn)為T。=T;hp——隧洞出口斷面水流的平均單位勢能，?a——出口斷面洞高;p/γ——出口斷面平均單位壓能，這里取計(jì)算如下表表3-3有壓流水位流量關(guān)系表Z(m)T0(m)hp(m)Q(m3/s)51330111167.33951431111197.66551532111227.24151633111256.12151734111284.35251835111311.97651936111339.0352037111365.548根據(jù)有壓流水位流量關(guān)系表繪出水位-流量關(guān)系圖：圖3-2有壓流水位-流量關(guān)系圖1.4調(diào)洪演算1.4.1設(shè)計(jì)洪水過程線等別確定由以上資料可知，隧洞的泄洪能力設(shè)定為20年一遇的洪水，故設(shè)計(jì)洪水過程線也為5%。1.4.2小結(jié)本次設(shè)計(jì)根據(jù)1976年的紅水電站設(shè)計(jì)洪水過程線表查得洪水重現(xiàn)期為20年一遇的設(shè)計(jì)標(biāo)準(zhǔn)洪水線如下表3-4所示，選取的時(shí)段為8月14日-8月21日,時(shí)段取△t=3h。表3-4設(shè)計(jì)洪水過程線（5%）

月、日時(shí)段流量（m3/s)8.14053935736611964912682157121875121789150737386561060910701210101594418931219621601000313006136091360121220151140181070211010170958391368659839128081577718746217171807813858681497941276315738187252170719069236746662964912636156231861121598200590357865739560125521553918532215322105091.4.3確定設(shè)計(jì)調(diào)洪的起始條件紅水電站的起調(diào)水位取導(dǎo)流隧洞的底板高程488m。庫容為52.94萬m3，當(dāng)洪水初臨時(shí)當(dāng)來量較小時(shí)，用導(dǎo)流隧洞進(jìn)行泄流，當(dāng)水位到達(dá)488m時(shí)開始泄洪。1.4.4設(shè)計(jì)洪水的演算紅水電站水位-庫容相關(guān)資料如表3-5所示，根據(jù)表3-5相關(guān)數(shù)據(jù)繪制出水庫庫容-水位曲線如圖3-3。表3-5紅水電站水位-庫容表水位（m)庫容（萬m3)48852.94490105.88492158.82494211.76496264.71498317.65500370.59502421.53504476.47506529.41508582.35510635.29512688.24514741.18516794.12518847.065209005221100圖3-3水位-庫容曲線Z-V壩體攔洪或圍堰擋水，會(huì)形成一部分庫容，此時(shí)就需要考慮水庫的調(diào)蓄作用，需要進(jìn)行調(diào)洪演算。故下面需對紅水電站進(jìn)行調(diào)洪演算，根據(jù)《水利水電工程施工組織設(shè)計(jì)手冊》第一卷523頁:Q或I式中Δt——計(jì)算時(shí)段。根據(jù)洪峰歷時(shí)的長短。通常選用3h、6h或12h;Q1、Q2——時(shí)段始末的入庫流量；q1、q2——時(shí)段始末的泄流量；V1、V2——時(shí)段始末的庫容本次計(jì)算時(shí)段取Δt=3h,計(jì)算過程如下表，得紅水電站q=f(V/Δt+q/2)輔助曲線計(jì)算表與紅水電站q={(V/Δt+q/2)輔助曲線計(jì)算圖。表3-6紅水電站q=f(V/Δt+q/2)輔助曲線計(jì)算表庫水位Z(m）總庫容V總（萬m3)堰頂以上庫容V（萬m3)V/Δt(m3/s)q(m3/s)q/2(m3/s)V/Δt+q/2(m3/s)48852.9400.00000.00490105.8852.9449.0252.2426.1275.14492158.82105.8898.04147.7571.875171.91494211.76158.82147.06271.42135.71282.77496264.71211.76196.07410.35205.175401.25498317.65264.71245.10567.23281.615528.72500370.59317.65294.12691.011345.5055639.63502421.53370.59341.14765.575382.7875725.93504476.47421.53392.16840.321420.1605812.32506529.41476.47441.18911.501456.7505897.93508582.35529.41490.19986.681491.3405981.53510635.29582.35539.211059.862529.9311069.14512688.24635.29588.231131.04566.521154.75514741.18688.24637.261206.219601.10951240.37516794.12741.18686.281265.094632.5471318.82518847.06794.12735.301321.347660.67351395.97520900847.06784.311375.302687.6511471.97圖3-4紅水電站q=f(V/Δt+q/2)輔助曲線計(jì)算圖用單輔助曲線法進(jìn)行調(diào)洪計(jì)算，得紅水電站調(diào)洪計(jì)算表和過程圖，計(jì)算過程如表:表3-7紅水電站半圖解法調(diào)洪計(jì)算表（P=5%）時(shí)段流量（m3/s)時(shí)段平均入庫流量Q（m3/s)V/Δt+q/2（m3/s)q（m3/s)庫水位Z（m)05395560.000.00488.003573556.00597.70488.496611592550.30591.34488.399649630589.00634.54489.0912682665.5619.90669.02489.6415712697647.90698.18500.1918751731.5681.20726.95500.9621789770724.30764.19501.9624737763721.10761.16501.9427865801760.90795.85502.81301060962.5927.60938.89506.6933107010651051.701046.70509.6436101010401047.001040.97509.4839944977981.00986.25507.9942931937.5934.30944.62506.8545962946.5936.10946.16506.89481000981971.00975.99507.7151130011501145.001124.67511.7754136013301350.301288.05516.8257136013601422.301340.02518.6960122012901372.201304.00517.3863114011801248.201212.08514.2066107011051141.201121.43511.6869101010401059.701051.83509.7872958984991.90991.86508.2075913935.5931.50994.94506.8378865889889.00897.00505.5581839852852.00858.53504.5084808821.5851.50828.47501.6887777792.5792.50797.32502.8590746761.5761.50766.35502.0293717731.5731.50736.20501.2196781749749.00747.25501.5199858819.5819.50809.78501.18102814836836.00832.45501.79105794804804.00807.885015778.