-2-某水電站工程的截流設(shè)計(jì)計(jì)算案例目錄TOC\o"1-3"\h\u22070某水電站工程的截流設(shè)計(jì)計(jì)算案例 -1-267801.1截流資料 -1-169431.2截流時(shí)段 -1-129491.3截流標(biāo)準(zhǔn) -2-70891.4截流戧堤高度 -2-236501.5戧堤頂寬與邊坡 -2-259651.6計(jì)算步驟 -3-274921.7繪制泄流曲線和龍口泄水曲線 -3-120131.7.1上游水位與隧洞泄流量關(guān)系 -3-312281.8龍口流量演算 -4-220171.8.1計(jì)算原理 -4-204251.8.2龍口流量演算起始條件 -7-103921.8.3龍口流量演算過(guò)程 -7-155241.8.4數(shù)值牛頓法求交點(diǎn) -12-46771.9截流材料及龍口分區(qū) -13-216401.9.1確定不同流速下的拋塊粒徑 -13-69081.9.2拋投料的區(qū)段劃分 -14-235091.10用料量計(jì)算 -16-1.1截流資料河道截流的方法有多種，如平堵法、立堵法、和在泄水道中預(yù)先修建閘墩,最后采用下閘的方式截?cái)嗨鞯?。本次設(shè)計(jì)采用單戧立堵進(jìn)占，理由如下:(1)立堵截流工作比較簡(jiǎn)易，而且成本更經(jīng)濟(jì)；(2)立堵截流法在我國(guó)歷史悠久，技術(shù)較為成熟；1.2截流時(shí)段根據(jù)當(dāng)?shù)厮馁Y料及施工總進(jìn)度安排，截流時(shí)刻初選在第二年11月末或12月，綜合考慮工程截流流量不大、截流落差和河床覆蓋層厚的特色，以及工期、天氣等要素，選擇截流時(shí)段應(yīng)選在枯水期，故選定11月末開(kāi)始截流。1.3截流標(biāo)準(zhǔn)本次設(shè)計(jì)采用月平均流量10年重現(xiàn)期洪水作為截流流量標(biāo)準(zhǔn)。根據(jù)水文資料可知,流量Q=l32.0m3/s并根據(jù)當(dāng)時(shí)實(shí)際情況和水文氣象預(yù)報(bào)加以修正,按修正后的流量進(jìn)行各項(xiàng)截流的準(zhǔn)備工作。1.4截流戧堤高度截流設(shè)計(jì)流量為Q0=132.0m3/s，查壩區(qū)水位流量關(guān)系表得，當(dāng)Q0=132.0m3/s時(shí)，通過(guò)插值法，求得下游天然水位H下=481.68m。但截流戧堤是將來(lái)形成圍堰的一部分，而且施工是連續(xù)進(jìn)行的，所以，直接設(shè)下游水位H下=487.89m為下游圍堰高程,得下游水深Hd=1.89m。隨著龍口的束窄，上游水位壅高，龍口合龍閉氣后上游水位達(dá)到最高，流速也達(dá)到最高，由上游導(dǎo)流隧洞泄流曲線查得截流設(shè)計(jì)流量時(shí)的上游水位Z上=491.70m，故表4-1可知，V級(jí)圍堰安全超高取0.5m，加上安全超高0.5m，得戧堤高程為492.20m。戧堤底板高程為488m，戧堤高度為1.2m，取整為HB=5m。表4-1不過(guò)水圍堰堰頂安全超高下限值圍堰型式圍堰級(jí)別ⅢⅣ~(yú)Ⅴ土石圍堰0.70.5混凝土圍堰、漿砌石圍堰0.40.31.5戧堤頂寬與邊坡同時(shí)根據(jù)國(guó)內(nèi)外工程實(shí)例，綜合施工現(xiàn)場(chǎng)布置、施工運(yùn)輸因素和施工條件，為滿足施工布置及并行三輛大型卡車運(yùn)輸要求，將戧堤寬度設(shè)為20m。根據(jù)基本資料，戧堤端部邊坡系數(shù)n=1,截流戧堤兩側(cè)邊坡比m=1:1.4。根據(jù)《水利水電工程施工組織設(shè)計(jì)規(guī)范》規(guī)定,當(dāng)河床的寬度小于80m時(shí)，可不安排預(yù)進(jìn)占和龍口。根據(jù)工程資料，壩址處河段河谷窄，河谷底寬30~40m，此時(shí)河床底寬度取為30m，將戧堤長(zhǎng)度設(shè)為30+5*1.4*2=44m,故不需設(shè)置兩岸戧堤，可直接進(jìn)行截流。根據(jù)實(shí)際工程截流案例以及截流的實(shí)際情況，龍口寬度與截流戧堤長(zhǎng)度相同，故取龍口寬度為B=44m。又因右岸需要開(kāi)挖隧洞，左岸有棄渣廠，故兩岸均有道路，截流設(shè)為雙向進(jìn)占，因此本工程設(shè)計(jì)采用單戧立堵進(jìn)占截流。1.6計(jì)算步驟當(dāng)可不考慮上游河床調(diào)蓄流量和戧堤滲流量時(shí)，截流水力計(jì)算圖解法可按照下面的步驟進(jìn)行：（1）繪制分流曲線Qd?Z（2）繪制龍口泄水曲線Qg（3）按照?qǐng)D解法求出幾組相應(yīng)的B，?H，Qg和Qd值，并繪制曲線簇；（4）判斷流態(tài)，求水深；（5）按照υ=Q（6）列表計(jì)算截流過(guò)程中水力參數(shù)，如上下游落差Z，龍口平均流速v等。1.7繪制泄流曲線和龍口泄水曲線1.7.1上游水位與隧洞泄流量關(guān)系根據(jù)計(jì)算公式Q0=Qg+根據(jù)圖4-1上游水位導(dǎo)流隧洞泄流量關(guān)系曲線，通過(guò)插值法，可得到上游水位與導(dǎo)流隧洞泄流量和龍口流量的關(guān)系。表4-2上游水位與導(dǎo)流隧洞泄流量和龍口流量的關(guān)系泄流量（Q0m3/s)上游下游落差Z(m)龍口流量Q（m3/s)水位H上（m)水深(m)水位H下（m)水深(m)04880487.891.890.1113220489.051.05487.891.891.1611240489.641.64487.891.891.759260490.182.18487.891.892.297280490.692.69487.891.892.852100491.083.08487.891.893.1932120491.463.46487.891.893.5712132491.73.7487.891.893.810圖4-1泄流量和龍口流量與落差的關(guān)系曲線1.8龍口流量演算1.8.1計(jì)算原理龍口泄水能力計(jì)算按照寬頂堰公式計(jì)算：Q=m其中：B——龍口平均過(guò)水寬度（m）；H0m——流量系數(shù)，按下式計(jì)算：當(dāng)ZH0≤當(dāng)ZH0>由連續(xù)方程可得龍口流速計(jì)算公式為：υ=其中：v——龍口計(jì)算斷面平均流速（m/s）；?——龍口計(jì)算斷面水深（m），若龍口有護(hù)底，應(yīng)從護(hù)底頂部算起；在立堵截流中，常常規(guī)定：（1）出現(xiàn)淹沒(méi)流時(shí)，h=hs（（2）出現(xiàn)非淹沒(méi)流時(shí)，h=hc（在進(jìn)展過(guò)程中，斷面形狀會(huì)發(fā)生變化，由最初的梯形斷面逐漸變?yōu)槿切螖嗝妗楹?jiǎn)化計(jì)算，在梯形斷面中，采用矩形斷面臨界水深代替梯形斷面臨界水深。當(dāng)斷面形狀為梯形時(shí)，梯形斷面龍口計(jì)算圖如圖4-2，此時(shí)：H0圖4-2梯形斷面龍口計(jì)算圖（1）淹沒(méi)流：h=hs，由于進(jìn)占過(guò)程中，龍口底部高程不變，故?B=B?2（2）非淹沒(méi)流：h=hα其中：n——戧堤端部邊坡系數(shù)，此處取n=1.3；α——計(jì)算斷面動(dòng)能修正系數(shù)，常取α=1.0。通過(guò)試算，將流量代入，得到計(jì)算簡(jiǎn)式：?故進(jìn)一步求出非淹沒(méi)流情況下龍口平均過(guò)水寬度B，即：B當(dāng)斷面形狀為三角時(shí)，斷面龍口計(jì)算如圖4-3，此時(shí)：H圖4-3三角形斷面龍口計(jì)算圖（1）淹沒(méi)流時(shí)：h=hs=（2）非淹沒(méi)流時(shí)：h=hc=1.8.2龍口流量演算起始條件（1）根據(jù)上述數(shù)據(jù)，確定龍口初始寬度為B=44m；（2）由幾何關(guān)系知，梯形變?yōu)槿切蔚呐R界寬度B1）當(dāng)龍口寬度B＞B2）當(dāng)龍口寬度B＜B（3）根據(jù)設(shè)計(jì)要求，進(jìn)展起始龍口寬度為44m，進(jìn)占寬度為4m。1.8.3龍口流量演算過(guò)程根據(jù)龍口流量演算起始條件，將龍口寬度B分為若干段，并考慮臨界值B臨界當(dāng)龍口寬度B=44m時(shí)，龍口流量與落差的關(guān)系如表4-3所示：表4-3龍口流量與落差表（B=44m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量41.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0030.0000.0041.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2631.26011.2241.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5931.59349.5141.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9331.92797.5641.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2635.260156.1641.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5935.594221.1641.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9335.927300.8541.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2636.260385.7641.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4736.467442.38當(dāng)龍口寬度B=40m時(shí)，龍口流量與落差的關(guān)系如表4-4所示：表4-4龍口流量與落差表（B=40m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量40.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0030.0000.0040.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2630.26012.5640.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5930.59343.7840.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9330.92786.3940.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2631.260138.4440.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5931.594198.9740.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9331.927267.3640.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2632.260343.2140.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4732.467393.85當(dāng)龍口寬度B=36m時(shí)，龍口流量與落差的關(guān)系如表4-5所示：表4-5龍口流量與落差表（B=36m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量36.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0026.0000.0036.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2626.26010.9036.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5926.59338.0636.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9326.92775.2136.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2627.260120.7336.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5927.594173.7836.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9327.927233.8636.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2628.260300.6536.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4728.467345.33當(dāng)龍口寬度B=32m時(shí)，龍口流量與落差的關(guān)系如表4-6所示：表4-6龍口流量與落差表（B=32m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量32.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0022.0000.0032.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2622.2609.2432.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5922.59332.3332.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9322.92761.0432.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2623.260103.0132.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5923.594148.5932.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9323.927200.3732.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2621.260258.1032.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4721.467296.81當(dāng)龍口寬度B=28m時(shí)，龍口流量與落差的關(guān)系如表4-7所示：表4-7龍口流量與落差表（B=28m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量28.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0018.0000.0028.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2618.2607.5828.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5918.59326.6128.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9318.92752.8728.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2619.26085.3028.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5919.594123.4028.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9319.927166.8728.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2620.260215.5428.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4720.467248.28當(dāng)龍口寬度B=24m時(shí)，龍口流量與落差的關(guān)系如表4-8所示：表4-8龍口流量與落差表（B=24m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量21.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0011.0000.0021.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2611.2605.9221.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5911.59320.8821.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9311.92741.6921.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2615.26067.5821.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5915.59498.2021.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9315.927133.3721.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2616.260172.9921.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4716.467199.76當(dāng)龍口寬度B=20m時(shí)，龍口流量與落差的關(guān)系如表4-9所示：表4-9龍口流量與落差表（B=20m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量20.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.0010.0000.0020.000.50488.390.391.28梯形非淹沒(méi)流0.3850.2610.2601.2620.001.00488.890.891.12梯形非淹沒(méi)流0.3850.5910.59315.1620.001.50489.391.391.08梯形非淹沒(méi)流0.3850.9310.92730.5220.002.00489.891.891.06梯形非淹沒(méi)流0.3851.2611.26049.8720.002.50490.392.391.05梯形非淹沒(méi)流0.3851.5911.59473.0120.003.00490.892.891.04梯形非淹沒(méi)流0.3851.9311.92799.8820.003.50491.393.391.03梯形非淹沒(méi)流0.3852.2612.260130.4320.003.81491.703.701.03梯形非淹沒(méi)流0.3852.4712.467151.24當(dāng)龍口寬度B=16m時(shí)，龍口流量與落差的關(guān)系如表4-10所示：表4-10龍口流量與落差表（B=16m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量16.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.006.0000.0016.000.50488.390.391.28梯形非淹沒(méi)流0.3850.266.2602.6016.001.00488.890.891.12梯形非淹沒(méi)流0.3850.596.5939.4416.001.50489.391.391.08梯形非淹沒(méi)流0.3850.936.92719.3516.002.00489.891.891.06梯形非淹沒(méi)流0.3851.267.26032.1516.002.50490.392.391.05梯形非淹沒(méi)流0.3851.597.59447.8216.003.00490.892.891.04梯形非淹沒(méi)流0.3851.937.92766.3816.003.50491.393.391.03梯形非淹沒(méi)流0.3852.268.26087.8816.003.81491.703.701.03梯形非淹沒(méi)流0.3852.478.467102.71當(dāng)龍口寬度B=13m時(shí)，龍口流量與落差的關(guān)系如表4-11所示：表4-11龍口流量與落差表（B=13m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量13.000.11488.000.00####梯形非淹沒(méi)流0.385hc0.003.0000.0013.000.50488.390.391.28梯形非淹沒(méi)流0.3850.263.2601.3513.001.00488.890.891.12梯形非淹沒(méi)流0.3850.593.5935.1413.001.50489.391.391.08梯形非淹沒(méi)流0.3850.933.92710.9713.002.00489.891.891.06梯形非淹沒(méi)流0.3851.261.26018.8713.002.50490.392.391.05梯形非淹沒(méi)流0.3851.591.59428.9313.003.00490.892.891.04梯形非淹沒(méi)流0.3851.931.92741.2613.003.50491.393.391.03梯形非淹沒(méi)流0.3852.265.26055.9613.003.81491.703.701.03梯形非淹沒(méi)流0.3852.475.46766.32當(dāng)龍口寬度B=10m時(shí)，龍口流量與落差的關(guān)系如表4-12所示：表4-12龍口流量與落差表（B=10m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量10.000.11488.000.00####三角形非淹沒(méi)流0.385hc0.000.0000.0010.000.50488.390.391.28三角形非淹沒(méi)流0.3850.330.3280.1410.001.00488.890.891.12三角形非淹沒(méi)流0.3850.750.7481.0710.001.50489.391.391.08三角形非淹沒(méi)流0.3851.171.1683.2610.002.00489.891.891.06三角形非淹沒(méi)流0.3851.591.5887.0310.002.50490.392.391.05三角形非淹沒(méi)流0.3852.012.00812.6410.003.00490.892.891.04三角形非淹沒(méi)流0.3852.432.42820.3310.003.50491.393.391.03三角形非淹沒(méi)流0.3852.852.84830.3010.003.81491.703.701.03三角形非淹沒(méi)流0.3853.113.10837.71當(dāng)龍口寬度B=7m時(shí)，龍口流量與落差的關(guān)系如表4-13所示：表4-13龍口流量與落差表（B=7m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量7.000.11488.00(1.50)(0.07)三角形非淹沒(méi)流0.385hc###(1.260)#NUM!7.000.50488.39(1.11)(0.45)三角形非淹沒(méi)流0.385###(0.933)#NUM!7.001.00488.89(0.61)(1.64)三角形非淹沒(méi)流0.385###(0.512)#NUM!7.001.50489.39(0.11)####三角形非淹沒(méi)流0.385###(0.092)#NUM!7.002.00489.890.395.13三角形非淹沒(méi)流0.3850.330.3280.147.002.50490.390.892.81三角形非淹沒(méi)流0.3850.750.7481.077.003.00490.891.392.16三角形非淹沒(méi)流0.3851.171.1683.267.003.50491.391.891.85三角形非淹沒(méi)流0.3851.591.5887.037.003.81491.702.201.73三角形非淹沒(méi)流0.3851.851.84810.28當(dāng)龍口寬度B=7m時(shí)，龍口流量與落差的關(guān)系如表4-14所示：表4-14龍口流量與落差表（B=7m）龍口寬度B落差Z上游水位H龍口上游水深H0Z/H0流態(tài)流量系數(shù)h平均寬度流量1.000.11488.00(3.00)(0.04)三角形非淹沒(méi)流0.385hc###(2.520)#NUM!1.000.50488.39(2.61)(0.19)三角形非淹沒(méi)流0.385###(2.193)#NUM!1.001.00488.89(2.11)(0.47)三角形非淹沒(méi)流0.385###(1.773)#NUM!1.001.50489.39(1.61)(0.93)三角形非淹沒(méi)流0.385###(1.353)#NUM!1.002.00489.89(1.11)(1.80)三角形非淹沒(méi)流0.385###(0.933)#NUM!1.002.50490.39(0.61)(1.10)三角形非淹沒(méi)流0.385###(0.512)#NUM!1.003.00490.89(0.11)####三角形非淹沒(méi)流0.385###(0.092)#NUM!1.003.50491.390.398.97三角形非淹沒(méi)流0.3850.330.3280.141.003.81491.700.705.44三角形非淹沒(méi)流0.3850.590.5880.59根據(jù)表4-3至4-14，繪制出不同寬度下落差和龍口流量的關(guān)系，并將落差與泄流量和龍口流量的關(guān)系曲線繪制在同一坐標(biāo)系中，如圖4-4所示：圖4-4不同寬度下落差與龍口流量和泄流量的曲線簇1.8.4數(shù)值牛頓法求交點(diǎn)由計(jì)算原理可知，在每一個(gè)特定的寬度B下，平均寬度B是關(guān)于H0變化的，流量系數(shù)也是根據(jù)H表4-15數(shù)值牛頓法計(jì)算結(jié)果龍口寬度B(m）龍口流量Qd(m3/s)高差Z(m)龍口平均寬度B（m）水深h（m）流速v（m/s）44100.11.5135.40.933.044097.261.631.480.993.123693.831.727.571.053.243289.661.8123.691.133.352881.521.9519.841.223.492478.122.1316.011.343.642069.812.3512.231.483.861658.222.638.011.681.331346.182.915.791.861.291010.663.692.071.82.8672.693.811.21.012.22得到龍口寬度B與斷面平均流速v關(guān)系曲線如圖所示：圖4-5龍口寬度B與斷面平均流速V關(guān)系曲線由圖和表可得，在截流中，最大流速為1.33m/s，發(fā)生在龍口寬度為16m處。1.9截流材料及龍口分區(qū)1.9.1確定不同流速下的拋塊粒徑截流拋投材料的穩(wěn)定計(jì)算，國(guó)內(nèi)外廣泛應(yīng)用的是伊茲巴什公式，即:v式中v——拋投材料的穩(wěn)定流速d——塊石折算成球體的化引直徑γ、γb——水的容重r=9.8KN/m3和塊石的容重γb=28KN/m3k——拋投材料的綜合穩(wěn)定系數(shù),對(duì)立堵截流,當(dāng)拋投材料為塊石時(shí)。此處k=0.9，根據(jù)上述公式，可以推導(dǎo)出粒徑計(jì)算公式為:d故各個(gè)流速對(duì)應(yīng)的拋投物料的粒徑，計(jì)算結(jié)果如表4-16所示:表4-16不同流速下粒徑計(jì)算成果表龍口寬度B（m）流速v（m/s)粒徑δ(m)443.040.31403.120.33363.240.36323.350.38283.490.41243.640.45203.860.5161.330.63131.290.62102.860.2872.220.171.9.2拋投料的區(qū)段劃分無(wú)論是平堵或立堵截流,大體都是按水力參數(shù)代入公式計(jì)算出所需材料的粒徑和數(shù)量,采用的方法是將合龍過(guò)程劃分為若干區(qū)段，按分區(qū)計(jì)算出最大的流速所需材料粒徑和相應(yīng)的數(shù)量。其實(shí)在實(shí)際截流過(guò)程中，每