土石壩設(shè)計(jì)計(jì)算書

目錄第一章調(diào)洪演算 11.1設(shè)計(jì)洪水過程線 11.2調(diào)洪演算 2第二章大壩剖面尺寸確定 122.1壩頂高程的確定 122.1.1壩頂超高 122.1.2壩頂高程計(jì)算方法 122.1.3波浪平均波高和平均波周期 122.1.4風(fēng)壅高度可按下式計(jì)算: 132.1.5波浪爬高 132.2計(jì)算過程（河底高程為1932.0m） 132.3壩頂寬度計(jì)算 172.4壩坡與馬道 172.5壩頂構(gòu)造 182.6反濾層和過濾層 18第三章溢洪道計(jì)算 193.1結(jié)構(gòu)設(shè)計(jì) 193.1.1引水渠 193.1.2控制段 193.1.3泄槽底板 193.1.4挑流消能 193.1.5邊墻結(jié)構(gòu)設(shè)計(jì) 193.2地基及邊坡處理設(shè)計(jì) 193.2.1地基開挖 193.2.2邊坡開挖及處理 193.3混凝土的強(qiáng)度、防滲、抗凍指標(biāo) 203.4控制段 203.5泄流能力計(jì)算： 213.6泄槽的水力計(jì)算 223.7挑流消能計(jì)算 24第四章導(dǎo)流隧洞計(jì)算 264.1洞型尺寸 264.2隧洞結(jié)構(gòu)設(shè)計(jì) 274.2.1襯砌厚度 274.2.2分縫 274.3水力計(jì)算 274.3.1過流能力的計(jì)算 274.3.2水面線的計(jì)算 284.3.3通氣孔面積計(jì)算 294.3.4消能計(jì)算 29第一章調(diào)洪演算1.1設(shè)計(jì)洪水過程線根據(jù)資料所給出的設(shè)計(jì)洪水過程線和施工期洪水過程線是，令△t=2小時(shí)，求得相同時(shí)間間隔的設(shè)計(jì)洪水過程線及施工期洪水過程線如表1-1表1-1QA水庫洪水過程線計(jì)算表(△t=2h=120min=7200s)P=0.1%P=2%P=5%P=10%△t(h)時(shí)間修勻流量時(shí)間修勻流量時(shí)間修勻流量時(shí)間修勻流量07日00:0038.77日00:0014.523日20:0017.423日20:0011.422:0040.32:0015.122:0025.022:0016.344:0041.84:0015.624日00:0026.324日00:0017.266:0045.36:0017.02:0027.52:0018.188:0048.88:0018.34:0028.84:0018.91010:0046.810:0017.56:0029.56:0019.41212:0044.712:0016.78:0030.28:0019.81414:0041.714:0015.610:0032.310:0021.21616:0038.716:0014.512:0034.512:0022.51818:0036.918:0013.814:0039.514:0024.12020:0041.220:0016.116:0043.416:0024.72222:0051.622:0021.618:0059.918:0033.9248日00:0062.08日00：0027.020:0050.020:0028.3262:0075.02:0022.722:0046.722:0026.4284:0098.34:0035.725日00：0047.425日00：0026.8306:0095.76:0034.82:0048.82:0027.6328:0093.08:0033.84:0042.04:0023.83410:0086.510:0031.46:0037.96:0022.93612:0080.112:0029.18:0033.88:0022.03814:0073.614:0026.710:0033.110:0021.14016:0067.116:0024.412:0032.312:0020.34218:0068.618:0024.914:0031.514:0019.44420:0077.920:0028.316:0030.716:0018.54622:0098.322:0035.718:0027.518:0017.7489日00:00127.29日00：0046.220:0026.720:0017.5502:00156.02:0055.622:0027.422:0017.9524:00150.54:0053.526日00：0028.026日00：0018.3546:00145.06:0050.42:0027.42:0017.9568:00174.08:0055.24:0026.74:0017.55810:00307.810:0097.66:0024.96:0016.36012:00388.112:00123.08:0023.18:0015.16214:00346.714:00106.710:0020.710:0013.56416:00260.616:0079.812:0018.312:0011.96618:00223.618:0067.714:0017.514:0011.46820:00195.020:0061.916:0016.816:0011.07022:00175.022:0057.018:0016.018:0010.57210日00:00160.010日00：0055.020:0015.220:0010.0742:00151.72:0052.7764:00143.34:0050.3786:00135.06:0048.0808:00132.08:0045.08210:00123.910:0042.68412:00115.912:0040.28614:00107.814:0037.78816:0099.716:0035.39018:0091.718:0032.99220:0084.020:0030.69422:0082.022:0029.99611日00:0080.011日00：0029.2982:0077.42:0028.61004:0074.84:0028.01026:0073.26:0027.41048:0071.58:0026.710610:0068.010:0025.410812:0064.412:0024.111014:0060.914:0022.711216:0057.316:0021.411418:0054.518:0020.411620:0052.920:0019.811822:0048.522:0018.412012日00：0048.012日00：0019.01.2調(diào)洪演算根據(jù)水庫水量平衡方程：在某一時(shí)段內(nèi)，入庫水量減去出庫水量，應(yīng)等于該時(shí)段內(nèi)水庫增加或減少的蓄水量。水量平衡方程為（1.1）式中Q1——時(shí)段始的入庫流量，m3/s；Q2——時(shí)段末的出庫流量，m3/s；V1——時(shí)段始的水庫蓄水量，m3/s；V2——時(shí)段末的水庫蓄水量，m3/s；——計(jì)算時(shí)段，s.其能比較準(zhǔn)確地反映洪水過程線地形狀。根據(jù)水庫入庫洪水過程線，式中Q1，Q2均為已知，V1、q1則是計(jì)算時(shí)段△t開始時(shí)的初始條件，未知數(shù)有兩個(gè)（V2、q2），對(duì)V2、q2進(jìn)行試算。根據(jù)水庫入庫洪水過程線，式中Q1，Q2均為已知，V1、q1則是計(jì)算時(shí)段△t開始時(shí)的初始條件，未知數(shù)有兩個(gè)（V2、q2），對(duì)V2、q2進(jìn)行試算。聯(lián)合另一方程：q2=f(H)=A.Hb(1.2)式中A系數(shù)，與建筑物形式和尺寸，閘孔開度以及淹沒系數(shù)有關(guān)系，A=m.B(2g)1/2；m流量系數(shù)；B堰頂高度；b指數(shù)，對(duì)于堰流一般為3/2。由式(1.1)和式(1.2)聯(lián)立,就可解出q2，V2兩個(gè)未知數(shù)，用兩個(gè)公式調(diào)洪計(jì)算的方法很多，常用試算法和半圖解法。本設(shè)計(jì)中采用試算法。利用Excel圖表分別繪制出P=0.1%和P=2%各個(gè)時(shí)段來水流量和下泄流量曲線圖，兩曲線相交點(diǎn)即為校核洪水位、設(shè)計(jì)洪水位。最終確定設(shè)計(jì)洪水位和校核洪水位。其校核洪水位計(jì)算過程表見表1.1，設(shè)計(jì)洪水位計(jì)算過程見表1.2。表1.1設(shè)計(jì)過程校核洪水位調(diào)洪演算過程（P=0.1%）時(shí)間△tQZVq(Q1+Q2)/2(q1+q2)/2△VV2'q2'Z2'7日00：00038.71994.709060.0039.4759.8621.3302:00240.31995.2592719.71927.3319.711995.2504:00441.81995.4993733.9441.02526.8210.22937.2233.941995.4906:00645.31995.5994140.5843.5537.264.53941.5340.581995.5908:00848.81995.6594444.7547.0542.663.16944.1644.751995.6510:001046.81995.6894546.8947.77545.821.41945.4146.891995.6812:001244.71995.6694545.4645.72546.17-0.32944.6845.461995.6614:001441.71995.6494444.0543.244.75-1.12943.8844.051995.6416:001638.71995.6094241.2640.242.66-1.77942.2341.261995.618:001836.91995.5694038.5437.839.90-1.52940.4838.541995.5620:002041.21995.5594137.8739.0538.210.61940.6137.871995.5522:002251.61995.6694445.4646.441.673.41944.4145.461995.668日00：002462.01995.7595052.0056.848.735.81949.8152.001995.7502:002675.01995.9495766.7368.5259.376.59956.5966.731995.9404:002898.31996.1596584.3986.6775.568.00965.0084.391996.1506:003095.71996.2797095.0796.97589.735.22970.2295.071996.2708:003293.01996.2597093.2694.32594.170.11970.1193.261996.2510:003486.51996.2296890.5789.7591.92-1.56968.4490.571996.2212:003680.11996.1596584.3983.28587.48-3.02964.9884.391996.1514:003873.61996.0796277.5076.83580.94-2.96962.0477.501996.0716:004067.11995.9995970.8170.36574.16-2.73959.2770.811995.9918:004268.61995.9695868.3667.8569.58-1.25957.7568.361995.9620:004477.91996.0395974.1373.23571.241.43959.4374.131996.0322:004698.31996.1696585.2688.179.706.05965.0585.261996.169日00：0048127.21996.41977108.07112.72596.6711.56976.56108.071996.4102:0050156.01996.72990138.75141.575123.4113.08990.08138.751996.7204:0052150.51996.86995153.43153.25146.095.16995.16153.431996.8606:0054145.01996.81993148.13147.75150.78-2.18992.82148.131996.8108:0056174.01996.91997158.78159.5153.464.35997.35158.781996.9110:0058307.81997.621026241.15240.875199.9729.451026.45241.151997.6212:0060388.11998.471062353.78347.915297.4636.321062.32353.781998.4714:0062346.71998.581066369.37367.375361.574.181066.18369.371998.5816:0064260.61998.051045296.34303.64332.85-21.031044.97296.341998.0518:0066223.61997.611026239.91242.09268.13-18.751026.25239.911997.6120:0068195.01997.341016207.31209.285223.61-10.321015.68207.311997.3422:0070175.01997.161007186.47185196.89-8.561007.44186.471997.1610日00：0072160.01996.971001165.29167.5175.88-6.041000.96165.291996.9702:0074151.71996.90997157.71155.85161.50-4.07996.93157.711996.904:0076143.31996.81993148.13147.5152.92-3.90993.10148.131996.8106:0078135.01996.75989141.86139.15144.99-4.21988.79141.861996.7508:0080132.01996.66986132.62133.5137.24-2.69986.31132.621996.6610:0082123.91996.61984127.58127.95130.10-1.55984.45127.581996.6112:0084115.91996.54981120.63119.885124.10-3.04980.96120.631996.5414:0086107.81996.44978110.93111.835115.78-2.84978.16110.931996.4416:008899.71996.38975105.24103.75108.08-3.12974.88105.241996.3818:009091.71996.2797295.0795.68100.16-3.22971.7895.071996.2720:009284.01996.2296890.5787.8392.82-3.59968.4190.571996.2222:009482.01996.1596584.398387.48-3.22964.7884.391996.1511日00：009680.01996.1396382.658183.52-1.81963.1982.651996.1302:009877.41996.0796277.5078.780.07-0.99962.0177.501996.0704:0010074.81996.0696176.6576.177.08-0.70961.3076.651996.0606:0010273.21996.0396074.1373.97575.39-1.02959.9874.131996.0308:0010471.51996.0195972.4672.32573.30-0.70959.3072.461996.0110:0010668.01995.9895869.9969.7571.23-1.06957.9469.991995.9812:0010864.41995.9495666.7366.20568.36-1.55956.4566.731995.9414:0011060.91995.8995562.7462.65564.74-1.50954.5062.741995.8916:0011257.31995.8695360.3859.161.56-1.77953.2360.381995.8618:0011454.51995.8195156.5255.9258.45-1.82951.1856.521995.8120:0011652.91995.7895054.2453.7255.38-1.20949.8054.241995.7822:0011848.51995.7494951.2650.752.75-1.48948.5251.261995.7412日00：0012048.01995.7294749.7948.2550.52-1.64947.3649.791995.729日14：00時(shí)Qmax=qmax（圖中兩曲線相交時(shí)刻），則校核洪水位1998.58m表1-2設(shè)計(jì)過程設(shè)計(jì)洪水位調(diào)洪演算過程（P=2%）時(shí)間△tQZVq(Q1+Q2)/2(q1+q2)/2△VV2'q2'Z2'7日00：00014.51994.709060.0014.82.848.6102:00215.11994.949155.68914.615.681994.9404:00415.61995.069204.2415.358.065.25920.254.241995.0606:00617.01995.1492314.1116.27512.272.88922.8814.111995.1408:00818.31995.1892516.0717.62515.091.83924.8316.071995.1810:001017.51995.2292618.1217.917.100.58925.5818.121995.2212:001216.71995.2192517.6017.117.86-0.55925.4517.601995.2114:001415.61995.1992416.5816.1517.09-0.68924.3216.581995.1916:001614.51995.1692315.0815.0515.83-0.56923.4415.081995.1618:001813.81995.1492314.1114.1414.59-0.33922.6714.111995.1420:002016.11995.1692315.0814.9414.590.25923.2515.081995.1622:002221.61995.2092517.0918.8516.081.99924.9917.091995.208日00：002427.01995.2792920.8024.318.943.86928.8620.801995.2702:002622.71995.3393124.1724.8522.481.70930.7024.171995.3304:002835.71995.3893427.1029.225.632.57933.5727.101995.3806:003034.81995.4893833.2935.22530.203.62937.6233.291995.4808:003233.81995.5093834.5834.27533.940.24938.2434.581995.5010:003431.41995.4893733.2932.633.94-0.96937.0433.291995.4812:003629.11995.4493630.7730.24532.03-1.28935.7230.771995.4414:003826.71995.4293429.5327.89530.15-1.62934.3829.531995.4216:004024.41995.3793226.5125.5528.02-1.78932.2226.511995.3718:004224.91995.3493124.7424.6525.63-0.70931.3024.741995.3420:004428.31995.3593225.3326.625.041.13932.1325.331995.3522:004635.71995.4393530.143227.743.07935.0730.141995.439日00：004846.21995.5494037.2140.9533.685.24940.2437.211995.5402:005055.61995.6894646.8950.942.056.37946.3746.891995.6804:005253.51995.7694952.7454.5549.823.41949.4152.741995.7606:005450.41995.7394950.5251.9551.630.23949.2350.521995.7308:005655.21995.7695052.7452.851.630.84949.8452.741995.7610:005897.61996.0296073.3076.463.029.63959.6373.301996.0212:0060123.01996.38975105.24110.389.2715.14975.14105.241996.3814:0062106.71996.47979113.81114.85109.523.83978.83113.811996.4716:006479.81996.2897195.9893.25104.90-8.39970.6195.981996.2818:006667.71996.0796277.5073.74586.74-9.36961.6477.501996.0720:006861.91995.9495766.7364.79572.12-5.27956.7366.731995.9422:007057.01995.8695460.3859.4563.56-2.96954.0460.381995.8610日00：007255.01995.8395258.055659.22-2.32951.6858.051995.8302:007452.71995.7795153.4953.8555.77-1.38950.6253.491995.7704:007650.31995.7695052.7451.553.12-1.17949.8352.741995.7606:007848.01995.7394850.5249.1551.63-1.79948.2150.521995.7308:008045.01995.6894646.8946.548.70-1.59946.4146.891995.6810:008242.61995.6694445.4643.846.17-1.71944.2945.461995.6612:008440.21995.6194241.9541.443.71-1.66942.3441.951995.6114:008637.71995.5794139.2238.9540.59-1.18940.8239.221995.5716:008835.31995.5494037.2136.538.21-1.23939.7737.211995.5418:009032.91995.5193835.2334.136.22-1.53938.4735.231995.5120:009230.61995.4793632.6631.7533.94-1.58936.4232.661995.4722:009429.91995.4493530.7730.2531.71-1.05934.9530.771995.4411日00：009629.21995.4293529.5329.5530.15-0.43934.5729.531995.4202:009828.61995.4293529.5328.929.53-0.45934.5529.531995.4204:0010028.01995.4193428.9128.329.22-0.66934.3428.911995.4106:0010227.41995.3893427.1027.67528.01-0.24933.7627.101995.3808:0010426.71995.3993427.7027.02527.40-0.27933.7327.701995.3910:0010625.41995.3793326.5126.0527.10-0.76933.2426.511995.3712:0010824.11995.3593225.3324.7525.92-0.84932.1625.331995.3514:0011022.71995.3393124.1723.424.75-0.97931.0324.171995.3316:0011221.41995.3093022.4622.0523.31-0.91930.0922.461995.3018:0011420.41995.2892921.3520.921.90-0.72929.2821.351995.2820:0011619.81995.2792820.8020.121.07-0.70928.3020.801995.2722:0011818.41995.2492719.1819.119.99-0.64927.3619.181995.2412日00：0012019.01995.2392718.6518.718.91-0.15926.8518.651995.239日14：00時(shí)Qmax=qmax（圖中兩曲線相交時(shí)刻），則設(shè)計(jì)洪水位1996.47m第二章大壩剖面尺寸確定2.1壩頂高程的確定2.1.1壩頂超高壩頂在水庫靜水位以上的超高按下式確定：（2.1）其中：Y壩頂超高，m；R最大波浪在壩頂?shù)呐栏撸琺；e最大風(fēng)壅水面高度，m；A安全超高，m，該壩為Ⅲ級(jí)建筑物，正常運(yùn)行時(shí)取A=0.7，非常運(yùn)行時(shí)取A=0.5。2.1.2壩頂高程計(jì)算方法壩頂高程等于水庫靜水位與壩頂超高之和，應(yīng)按以下運(yùn)用條件計(jì)算，取其最大值:1.設(shè)計(jì)水位加正常運(yùn)用條件下的壩頂超高;2.正常蓄水位加正常運(yùn)用條件下的壩頂超高;3.校核洪水位加非常運(yùn)用條件下的壩頂超高；4.正常蓄水位加非常運(yùn)用條件下的壩頂超高加地震安全加高。2.1.3波浪平均波高和平均波周期波浪的平均波高和平均波周期宜采用莆田試驗(yàn)站公式：=（2.2）T=4.438×hm（2.3）L=（2.4）其中：hm——平均波高，m；T——平均波周期，s；L——平均波長(zhǎng)，m；D——風(fēng)區(qū)長(zhǎng)度.km；——壩前水深，m；W——計(jì)算風(fēng)速,m/s；2.1.4風(fēng)壅高度可按下式計(jì)算: （2.5）式中：e——計(jì)算處的風(fēng)壅水面高度，m；D——風(fēng)區(qū)長(zhǎng)度，km；K——綜合摩阻系數(shù)3.6×10-6；β——計(jì)算風(fēng)向與壩軸線的夾角0°。2.1.5波浪爬高設(shè)計(jì)波浪爬高值應(yīng)根據(jù)工程等級(jí)確定，3級(jí)壩采用累積頻率為1%的爬高值.平均波浪爬高可按下式或有關(guān)規(guī)定計(jì)算:（2.6）式中：Rm——波浪的平均爬高；K△——斜坡的糙率滲透性系數(shù)，護(hù)面類型選用砌石護(hù)坡，根據(jù)護(hù)面類型查規(guī)范得0.75；Kw——經(jīng)驗(yàn)系數(shù)，查規(guī)范得1.0；m——單坡的坡度系數(shù)，若坡角為，即等于ctg，本設(shè)計(jì)取m=3查規(guī)范1%累積頻率下的爬高與平均爬高的比值為2.23，故R=2.23Rm。2.2計(jì)算過程（河底高程為1932.0m）1、設(shè)計(jì)水位加正常運(yùn)用條件下的壩頂超高設(shè)計(jì)水位1996.47m吹程D=2.12㎞風(fēng)速W=1.5×12=18m/s壩前水深=64.47mβ=0°根據(jù)公式（2-2）求解得：hm=0.385434mT=4.438×hm=2.755258sL==11.84652m查規(guī)范1﹪?yán)鄯e頻率下的爬高與平均爬高的比值為2.23R1%=2.23×0.506794=1.180831m壩頂在水庫靜水位以上的超高按下式確定：Y=R+e+A=1.180831+0.002048+0.7=1.882879m壩頂高程：1996.47+1.882879=1998.373m2、正常蓄水位加正常運(yùn)用條件下的壩頂超高正常蓄水位1994.7m吹程D=2.12㎞風(fēng)速W=1.5×12=18m/s壩前水深Hm=62.7mβ=0°根據(jù)公式（2-2）求解得hm=0.385403mT=4.438×hm=4.438×0.385403=2.755148sL==11.84558m=0.75×1.0×/=0.506754m查規(guī)范不同累積頻率下的爬高與平均爬高的比值為2.23R1%=2.23×0.506754=1.180737m壩頂在水庫靜水位以上的超高按下式確定：Y=R+e+A=1.882785m壩頂高程：1994.7+1.882785=1996.583m3、校核洪水位加非常運(yùn)用條件下的壩頂超高校核洪水位1998.58m吹程D=2.12㎞風(fēng)速W=12m/s壩前水深Hm=66.58mβ=0°根據(jù)公式（2-2）求解得hm=0.246289mT=4.438×hm=2.202469sL==7.569826m=0.75×1.0×/=0.323837m查規(guī)范不同累積頻率下的爬高與平均爬高的比值為2.23R1%=2.23×0.323837=0.754541m壩頂在水庫靜水位以上的超高按下式確定：Y=R+e+A=0.754541+0.00091+0.5=1.255451m壩頂高程：1998.58+1.255451=1999.855m4、正常蓄水位加非常運(yùn)用條件下的壩頂超高加地震安全加高正常蓄水位1994.7m吹程D=2.12㎞風(fēng)速W=12m/s壩前水深Hm=62.7mβ=0°根據(jù)公式（2-2）求解得hm=0.24627mT=4.438×hm=2.202384sL==7.569243m=0.75×1.0×/=0.323812m查規(guī)范不同累積頻率下的爬高與平均爬高的比值為2.23R1%=2.23×0.323812=0.754482m壩頂在水庫靜水位以上的超高按下式確定： Y=R+e+A =0.754482+0.00091+0.5 =1.255393m根據(jù)DL5073-1997《水工建筑物抗震設(shè)計(jì)規(guī)范》要求，地震安全加高按設(shè)計(jì)地震烈度和壩前水深情況取為0.5～1.5m，本設(shè)計(jì)取1.0壩頂高程1994.7+1.255393+1.0=1996.955m綜上所述，四種情況中取最大值，即校核洪水位加非常運(yùn)用條件下的壩頂高程：1999.855m，則壩高：1999.855-1932.0=67.855m,取為68m.設(shè)計(jì)的壩頂高程是針對(duì)壩沉降穩(wěn)定以后的情況而言的，因此，竣工時(shí)的壩頂高程就預(yù)留足夠的沉降量，一般施工質(zhì)量良好的土石壩，壩體沉降量約為壩高的0.2%～0.4%，此處取為0.3%壩頂高程：1998.855+0.3%×68=2000.059m，為方便計(jì)算取為2000.0m綜合情況見下表2-1：表2-1各種工況下的壩頂高程計(jì)算情況計(jì)算項(xiàng)目正常運(yùn)用情況非常運(yùn)用情況正常蓄水位設(shè)計(jì)洪水位正常蓄水位校核洪水位上游靜水位（m）1994.71996.471994.71998.58河底高程（m）1932.0壩前水深（m）62.764.4762.766.58吹程（km）2.12風(fēng)向與壩軸線夾角（°）0風(fēng)浪引起壩前雍高（m）0.0020480.0020480.000910.00091風(fēng)速V（m/s）1812波高h(yuǎn)m(m)0.3854030.3854340.246270.246289護(hù)坡粗糙系數(shù)0.75上游壩面坡腳arctg1/3.0波浪沿壩面爬高（m）1.1807371.1808310.7544820.754541安全超高（m）0.70.5地震安全加高（m）01.00壩頂高程（m）1996.5831998.3731996.9551999.855綜上所述，此大壩壩頂高程為2000.0m，壩高為68m。2.3壩頂寬度計(jì)算壩體寬度必須考慮斜心墻或斜墻頂部及反濾層布置的需要。土石壩壩頂寬度根據(jù)運(yùn)行、施工、構(gòu)造、交通和人防等方面的要求綜合研究后確定，SL274-2001《碾壓土石壩設(shè)計(jì)規(guī)范》要求高壩的最小頂寬為10～15m，中低壩則為5～10m。此壩壩高為68m，為中壩，故其壩頂寬度取為10m。壩頂?shù)淖钚挾纫部砂?水工建筑物（中國(guó)水利水電出版社P283）公式式中：H為壩高，m；R為所求壩頂寬度。此壩壩高為68m，為中壩，故其壩頂寬度取為10m。2.4壩坡與馬道土石壩壩坡的選擇取決于壩型、壩高、壩的等級(jí)、壩體及壩基材料材料的性質(zhì)、承受的荷載、施工和運(yùn)行等主要因素。一般可參考已建壩的實(shí)踐經(jīng)驗(yàn)或用近似的計(jì)算方法初步擬定壩坡，然后進(jìn)行穩(wěn)定等計(jì)算確定合理的壩坡。在滿足穩(wěn)定要求的前提下，應(yīng)盡可能使壩坡陡些，以減小壩體工程量。根據(jù)規(guī)范規(guī)定與實(shí)際結(jié)合，上游壩坡考慮在一半壩高處變坡一次，上部取2.5，下部取3.0，下游壩坡自上而下均取為2.5。在壩坡改變處，尤其在下游坡，通常設(shè)置1.5～2.0m的馬道以使匯集壩面的雨水，防止沖刷壩坡，并同時(shí)兼作交通、觀測(cè)、檢修之用，綜合上述等各方面的因素取其寬度為2.0m。2.5壩頂構(gòu)造本工程屬于中壩，根據(jù)運(yùn)行、施工交通的方便，壩頂寬度定為10m，壩頂路面的材料采用瀝青混凝土，壩頂面向下游側(cè)放坡，由于當(dāng)?shù)氐慕涤炅坎⒉粡?qiáng)，所以坡度取i=0.02。在上游側(cè)設(shè)防浪墻，高度為1.2m，下游側(cè)設(shè)置欄桿。詳見圖QA-1。2.6反濾層和過濾層按照1.被保護(hù)土不發(fā)生滲透變形；2.滲透性大于被保護(hù)土，能通暢地排出滲透水流；3.不致被細(xì)粒土淤塞失效的原則進(jìn)行反濾層設(shè)計(jì)，過渡層采用連續(xù)級(jí)配，最大粒徑小于300mm，采用等厚度。第三章溢洪道計(jì)算3.1結(jié)構(gòu)設(shè)計(jì)3.1.1引水渠引水渠采用與泄槽等寬，其B=27m。底板高程為1989.20m，采用厚為0.5m的C25混凝土進(jìn)行襯砌。邊墻采用重力式擋土墻，上寬為0.5m，底寬為2.5m

。進(jìn)水段由于受地形的限制，為了減小開挖量，則采用圓弧形導(dǎo)墻進(jìn)行引水，在靠近溢流堰處設(shè)置于直墻段，其長(zhǎng)度L=26米。3.1.2控制段控制段的結(jié)構(gòu)形式可采用分離式或整體式，分離式適合用于巖性比較均勻的地基。整體式是用于地基均勻性較差的情況，本工程地質(zhì)條件較好，巖性較均勻，可采用分離式。3.1.3泄槽底板泄槽底板厚度考慮溢洪道規(guī)模及其與壩的相對(duì)位置、沿線的工程地質(zhì)條件、水力特性、氣候提條件、水流中挾沙情況等因素，并根據(jù)類似工程經(jīng)驗(yàn)類比確定，泄槽的底板厚度不應(yīng)小于0.3米，本工程泄槽地板厚度為0.5米。泄槽地板設(shè)置結(jié)構(gòu)縫，分塊尺寸考慮到氣候條件、地基約束情況、混凝土施工條件，加上類似工程經(jīng)驗(yàn)確定，其橫縫間距采用15米，中間設(shè)一條縱縫。3.1.4挑流消能反弧半徑R可采用反弧最低點(diǎn)最大水深h的6～12倍。由于采用挑流，且挑流鼻坎建在巖基上，所以不設(shè)襯砌，僅在末端設(shè)置出口挑流結(jié)構(gòu)，將泄流挑入原河床。3.1.5邊墻結(jié)構(gòu)設(shè)計(jì)泄槽兩側(cè)的邊墻高由泄槽的水面曲線加上超高來確定，由于泄槽采用同一坡度，則其邊墻高度一致，取3m。采用重力式，其尺寸見QX-03中泄槽橫剖面圖。3.2地基及邊坡處理設(shè)計(jì)3.2.1地基開挖根據(jù)建筑物對(duì)地基的要求結(jié)合地質(zhì)條件，工程處理措施等綜合研究確定，地基開挖至弱風(fēng)化層的中上部，開挖面平順。在控制段的基坑略向上游傾斜。3.2.2邊坡開挖及處理根據(jù)巖體質(zhì)量、巖體結(jié)構(gòu)特征、邊坡高度和施工方法等條件，通過工程類比法，取溢洪道的開挖邊坡為1：0.33.3混凝土的強(qiáng)度、防滲、抗凍指標(biāo)1、材料強(qiáng)度標(biāo)準(zhǔn)：混凝土強(qiáng)度標(biāo)準(zhǔn)等級(jí)不宜低于《水工混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范》中4.4.2條中表4.4.2所列數(shù)值。而有抗沖耐磨要求的部位，混凝土強(qiáng)度等級(jí)不應(yīng)低于C25。故泄槽的混凝土采用C25等級(jí)。2、材料抗?jié)B性指標(biāo)：由于溢洪道有抗?jié)B要求，混凝土應(yīng)滿足有關(guān)抗?jié)B等級(jí)的規(guī)定，混凝土抗?jié)B等級(jí)按28天齡期的標(biāo)準(zhǔn)試件測(cè)定，混凝土抗?jié)B等級(jí)分為：W2、W4、W6、W8、W10、W12六級(jí)。而再根據(jù)所承受的水頭、水力梯度以及下游排水條件、水質(zhì)條件和滲透水的危害程度等因素，混凝土的抗?jié)B等級(jí)不得低于《水工混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范》表4.4.5所列數(shù)值。對(duì)于溢流堰大體積混凝土結(jié)構(gòu)的擋水面，而且H<30，所以等級(jí)為W4。3、材料抗凍指標(biāo)混凝土的抗凍等級(jí)按28天齡期的試件用快凍實(shí)驗(yàn)方法測(cè)定，分為F400、F300、F200、F150、F100、F50六級(jí)。對(duì)于混凝土的抗凍指標(biāo)可在《水工混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范》表中查得抗凍等級(jí)為F300。3.4控制段溢流堰為正堰，堰頂下游采用WES型冪曲線，堰頂上游堰頭采用三圓弧曲線，采用高堰設(shè)計(jì).高堰堰高要符合p＞1.33Hd,Hd=（0.75～0.95）Hmax,Hmax=最高洪水位－堰頂高程=1998.58－1994.7=3.88m。經(jīng)計(jì)算Hd=3.35m，p=4.46m，取4.5m。而下游堰面曲線可按下式計(jì)算：xn=KHdn-1y（3.1）其中Hd——堰面曲線定型設(shè)計(jì)水頭；x、y——原點(diǎn)下游堰面曲線橫、縱坐標(biāo)；n——與上游堰坡有關(guān)的指數(shù)；k——當(dāng)p1/Hd>1.0時(shí)，k值見規(guī)范表A.1.1；當(dāng)p1/hd≤1.0時(shí)，取k=2.0～2.2。在《溢洪道設(shè)計(jì)規(guī)范》表A.1.1可查出k=1.936，n=1.836。則公式可寫為:x1.836=1.936×3.350.836由此式可繪出下游曲線。上游堰頭曲線由雙圓弧曲線組成，其相關(guān)參數(shù)如下：R1=0.68Hd=2.278，R2=0.21Hd=0.7035，a=0.139Hd=0.4657，b=0.273Hd=0.9146反弧段半徑r=（0.25～0.5）（Hd+zmax），取8m。3.5泄流能力計(jì)算：開敞式WES型實(shí)用堰的泄流能力可按公式-溢洪道設(shè)計(jì)規(guī)范（中國(guó)電力出版社P45）計(jì)算：（3.2）式中Q—流量，m3/sB—溢流堰總凈寬度，定義B=nb=26m；b—單孔寬度，13.5m；n—閘孔數(shù)目,2;H0—計(jì)入行近流速的堰上總水頭，4.42m;g—重力加速度,9.81;m—實(shí)用堰流量系數(shù)經(jīng)下表取值,計(jì)算后取0.507;c—上游堰坡影響系數(shù),經(jīng)下表取值，取為0.997；ε—閘墩側(cè)收縮系數(shù)；表3.1流量系數(shù)m值H0/HdP1/Hd0.20.40.61.01.330.40.4250.4300.4310.4330.4360.50.4380.4420.4450.4480.4510.60.4500.4550.4580.4600.4640.70.4850.4630.4680.4720.4760.80.4670.4740.4770.4820.4860.90.4730.4800.4850.4910.4941.00.4790.4860.4910.4960.5011.10.4820.4910.4960.5020.5071.20.4850.4950.4990.5060.5101.30.4960.5000.5000.5080.513表3.2上游面坡度影響修正系數(shù)C值上游壩面坡度（）P1/Hd0.30.40.60.81.01.21.33:10.0091.0071.0041.0021.0000.9980.9973:20.0151.0111.0061.0020.9990.9960.9933:31.0211.0151.0071.0020.9980.9960.988（3.3）上式適用于H0/b≤1.0,當(dāng)H0/b＞1.0，H0/b,仍取值1.0。式中ε0—中墩形狀系數(shù)；ζk—邊墩形狀系數(shù)；σs—淹沒系數(shù)。得：ε=0.977故可計(jì)算得Q=426.66m3/s＞390.295m3/s，可以滿足最大洪峰下泄流量。（詳見計(jì)算書）3.6泄槽的水力計(jì)算1.臨界水深和臨界底坡計(jì)算泄槽采用矩形斷面其臨界水深和臨界底坡可按公式-溢洪道設(shè)計(jì)規(guī)范（中國(guó)電力出版社P51）計(jì)算：（3.4）（3.5）式中Q——最大下泄流量m3/s；n——泄槽槽身糙率系數(shù)，0.014；Rk——水力半徑，m；Bk——泄槽寬度，m。經(jīng)計(jì)算hk=3.22，ik=0.00182.水面線計(jì)算（1）起始斷面水深計(jì)算根據(jù)《溢洪道設(shè)計(jì)規(guī)范P53》可知，泄槽上游接實(shí)用堰時(shí)，起始計(jì)算斷面定在堰下收縮斷面處，泄槽起始斷面水深小于,可按下式計(jì)算：(3.6)式中Q——計(jì)算斷面單寬流量，；——起始計(jì)算斷面渠底以上總水頭，取3.95m，——泄槽底坡坡角，——起始計(jì)算斷面流速系數(shù)，取為0.95；（2）采用逐段試算法進(jìn)行水面線計(jì)算具體做法是把河流分為若干段，然后對(duì)每一段△s應(yīng)用以下公式進(jìn)行計(jì)算（3.7）式中——流段的兩端斷面上斷面比能差值；Esd——流段下游斷面比能；Esu——流段上游斷面比能；J——流段平均水力坡度；J=,以上公式中，K=，A=（b+mh）h，R=,經(jīng)計(jì)算得最終結(jié)果見下表表8.3水面線計(jì)算表H(m)A(m2)v（m/s）v2/2gmEs（m）ΔEsmRJi-J△sS(m)1.5634.3211.376.598.151.370.0181.4030.8012.678.189.581.432.761.240.207.157.151.2026.4014.7811.1412.342.761.080.040.1914.5321.681.0022.0017.7416.0417.044.701.080.0690.11628.4050.080.8017.6022.1825.0625.868.820.750.140.1176.86126.943.邊墻高度泄槽兩側(cè)的邊墻高由泄槽的水面曲線加上超高來確定，由于泄槽采用同一坡度，則其邊墻高度一致，本次設(shè)計(jì)取3m。3.7挑流消能計(jì)算1.水舌挑距：水舌挑距按水舌外緣計(jì)算，按-溢洪道設(shè)計(jì)規(guī)范（中國(guó)電力出版社P59）公式計(jì)算：（3.8）式中L——自挑坎坎頂算起的挑流水舌與下游面交點(diǎn)的水平距離。m；——坎頂水面流速，，可按鼻坎處平均流速V的1.1倍計(jì)；挑射角，取30；鼻坎鉛直方向水深，m；；（h為坎頂法向平均水深），3.8m；坎頂?shù)较掠嗡娴母卟?，m；21.77m。鼻坎處平均流速：0.946=25.26代入數(shù)據(jù)得：L=92.1m2.沖坑深度：沖坑最大水墊深度按-按溢洪道設(shè)計(jì)規(guī)范（中國(guó)電力出版社P60）公式計(jì)算：（3.9）式中：t——自下游水面至坑底的最大水墊深度，m當(dāng)t<H2時(shí)，采用H2；K——沖刷系數(shù)，查規(guī)范取0.8；——坎頂單寬流量，14.05——上，下游水位差，為60.94m;代入數(shù)據(jù)計(jì)算得：3.校核情況挑距所以滿足要求。（詳見計(jì)算書）第四章導(dǎo)流隧洞計(jì)算4.1洞型尺寸在設(shè)計(jì)通過16m3/s的一定流量時(shí),對(duì)于無壓隧洞,要用明渠均勻流公式，先假定斷面尺寸，進(jìn)行試算，一直算到和設(shè)計(jì)規(guī)定的流量相等的方式來確定隧洞的斷面尺寸，根據(jù)教學(xué)安排，指定本人進(jìn)行3m洞徑的輸水隧洞設(shè)計(jì)，斷面尺寸的高寬比為1:1.2。在隧洞的進(jìn)口之后用拋物線段、斜坡段及反弧段與導(dǎo)流洞的洞身相接。表孔進(jìn)口后的拋物線段底板應(yīng)符合射流曲線并有一定的安全值，以便閘門在不同開度時(shí)均能保持一定的正壓。由于本設(shè)計(jì)的起始流速為水平，所以拋物線方程為：（4.1）式中H工作閘門處孔口頂緣的最大設(shè)計(jì)水頭，38.6m；ψ修正流速及保持邊界正壓的系數(shù)，一般在1.18-1.30范圍內(nèi)，取1.20；x,y橫，縱坐標(biāo)表4-5拋物線底板曲線表y(m)0.501.002.003.004.005.006.007.00x(m)10.5414.9121.1025.8029.8033.3036.5039.50進(jìn)水口采用頂板和邊墻順?biāo)鞣较蛉媸湛s的平底矩形斷面，其體形應(yīng)符合孔口泄流的形態(tài)，避免產(chǎn)生不利的負(fù)壓和空蝕破壞，同時(shí)還應(yīng)盡量減少局部水頭損失，以提高輸水能力，本工程進(jìn)口段喇叭口的頂板和邊墻采用橢圓曲線，其方程為：（4.2）式中a橢圓長(zhǎng)半