污水管道的設(shè)計(jì)1、確定排水區(qū)界及劃分排水流域排水區(qū)界是污水排水系統(tǒng)設(shè)置的界限。凡是采用完善衛(wèi)生設(shè)備的建筑區(qū)都應(yīng)設(shè)置污水管道。它是根據(jù)城鎮(zhèn)總體規(guī)劃的設(shè)計(jì)規(guī)模決定的。在排水區(qū)界內(nèi)，根據(jù)地形及城鎮(zhèn)的豎向規(guī)劃，劃分排水流域。一般在丘陵及地形起伏的地區(qū)，可按等高線劃出分水線，通常分水線與流域分界線基本一致。在地形平坦無顯著分水線的地區(qū)，可依據(jù)面積的大小劃分，使各相鄰流域的管道系統(tǒng)能合理分擔(dān)排水面積，使干管在合理埋深情況下，流域內(nèi)絕大部分污水能以自流方式接入。每個(gè)排水流域往往有1個(gè)或1個(gè)以上的干管，根據(jù)流域地勢(shì)標(biāo)明水流方向和污水需要抽升的地區(qū)。城市排水流域劃分情況如圖：城市排水管網(wǎng)平面布置圖。2、排水管道的定線3、排水管道定線原則[2]在城鎮(zhèn)（地區(qū)）總平面圖上確定污水管道的位置和走向，稱污水管道系統(tǒng)的定線。正確的定線是合理的、經(jīng)濟(jì)的設(shè)計(jì)污水管道系統(tǒng)的先決條件，是污水管道系統(tǒng)設(shè)計(jì)的重要環(huán)節(jié)。管道定線一般按主干管、干管、支管順序依次進(jìn)行。定線應(yīng)遵循的主要原則是：應(yīng)盡可能地在管線較短和埋深較小的情況下，讓最大區(qū)域的污水能自流排出。4、定線的影響因素（1）地形和用地布局；（2）排水體制和線路數(shù)目；（3）污水廠和出水口位置；（4）水文地質(zhì)條件；（5）道路寬度，地下管線構(gòu)筑物的位置；（6）工業(yè)企業(yè)和產(chǎn)生大量污水的建筑物的分布情況。在一定的條件下，地形一般是影響管道定線的主要因素。定線時(shí)應(yīng)充分利用地形，使管道的走向符合地形趨勢(shì)，一般宜順坡排水。在整個(gè)排水區(qū)域較低的地方，例如集水線或河岸低處敷設(shè)主干管及干管，這樣便于支管的污水自流接入，而橫支管的坡度盡可能與地面坡度一致。在地形平坦地區(qū)，應(yīng)避免小流量的橫支管長距離平行于等高線敷設(shè)，讓其盡早接入干管。宜使干管與等高線垂直，主干管與等高線平行敷設(shè)。由于主干管管徑較大，保持最小流速所需要的坡度小，其走向與等高線平行是合理的。當(dāng)?shù)匦纹露群艽髸r(shí)，主干管與等高線垂直，干管與等高線平行。這種布置雖然主干管坡度較大，但是可設(shè)置為數(shù)不多的跌水井，使干管的水利條件得到改善。有時(shí)候，由于地形的原因還可以布置幾個(gè)獨(dú)立的排水系統(tǒng)。5、定線方案比較根據(jù)定線原則及影響因素，本設(shè)計(jì)有兩種不同的定線方案。方案一：干管與等高線垂直，主干管與等高線平行敷設(shè)。方案二：主干管與等高線垂直，干管與等高線平行布置。方案比較：兩種方案均充分利用了地形的原有坡度，污水都可依靠重力自流，在綜合考慮各種因素的條件下，采取干管與等高線垂直，主干管與等高線平行的方式。污水管道水力計(jì)算（1）、在小區(qū)平面圖上布置污水管道從城市小區(qū)平面圖和基本資料可知該城市地勢(shì)大至北高南低，城市南部有一條自西向東流的河流，城市位于河北岸，一條鐵路貫穿城區(qū)，鐵路把城市分成兩個(gè)區(qū)，該市區(qū)有兩座大型工廠，Ⅰ區(qū)有醫(yī)院，Ⅱ區(qū)有甲廠和乙廠，可劃分為兩個(gè)排水流域,排水體制為采用分流制。街道支管布置街區(qū)地勢(shì)較低一側(cè)的道路下，干管基本上與等高線垂直布置，Ⅰ區(qū)主干管沿小區(qū)南面布置，基本與等高線平行；Ⅱ區(qū)主干管也沿小區(qū)南面布置，基本與等高線平行。整個(gè)管道系統(tǒng)呈截流式形式布置，如吉林地區(qū)G縣排水管網(wǎng)平面布置圖中所示。（2）、街區(qū)編號(hào)并計(jì)算其面積將各街區(qū)編上號(hào)碼，并按各街區(qū)的平面范圍計(jì)算它們的面積，列入表7-1街區(qū)面積統(tǒng)計(jì)表中。用箭頭標(biāo)出各街區(qū)污水排出的方向。街區(qū)序號(hào)面積ha街區(qū)序號(hào)面積ha街區(qū)序號(hào)面積ha12.4136.5825326.12144.72261.2734.03151.43271.543.57163.38281.8554.2174.95291.4364.49182.71303.8573.78193.59317.382.72204.61328.193.84213.22338.51103.71222.78344.9112.15231.49354.68123.59245.13362.66371.35392.32411.85380.7401.16街區(qū)編號(hào)面積統(tǒng)計(jì)表（3）、劃分設(shè)計(jì)管段、計(jì)算設(shè)計(jì)流量根據(jù)設(shè)計(jì)管段的定義和劃分方法，將各干管和主干管中有本段流量進(jìn)入的點(diǎn)（一般定為街區(qū)兩端）、集中流量及旁側(cè)支管進(jìn)入的點(diǎn)，作為設(shè)計(jì)管段的起訖點(diǎn)的檢查井并編上號(hào)碼。本設(shè)計(jì)中的有四條干管，根據(jù)地形的情況，可分別劃分6-5-4-3-2；13-12-11-10-9-8-14；29-29-27-26-25-24-30-17；33-23-22-32-21-20-19-18；主干管：31-2-1-7-14-15-16-17-18a.計(jì)算比流量居住區(qū)人口密度為500cap/ha，居民生活污水定額為160L/(cap﹒d),則每ha街區(qū)面積的生活污水平均流量（比流量）為：其中：q0——單位面積的本段平均流量N——居民區(qū)生活污水定額（L/(s.ha)）P——人口密度（cap/ha）工業(yè)區(qū)人口密度為250cap/ha，居民生活污水定額為100L/(cap﹒d),則每ha街區(qū)面積的生活污水平均流量（比流量）為：其中：q0——單位面積的本段平均流量N——居民區(qū)生活污水定額（L/(s.ha)）P——人口密度（cap/ha）本設(shè)計(jì)中有4個(gè)集中流量根據(jù)本縣引進(jìn)外資的，建立各種輕工業(yè)廠區(qū)，比較大的有以下幾個(gè)：絲織廠：污水量為1800m3/d，k總＝2.5Q==52.1L/s塑料廠：污水量為3000m3/d,k總＝2.1Q==72.9L/s印染廠：污水量為2400m3/d,k總＝2.3Q==63.9L/s原有的縣醫(yī)院擴(kuò)建至一定規(guī)模，其污水量約為2000m2/d,k總＝1.9Q==39.4L/sb.計(jì)算出各管段流量如下管段編號(hào)居民生活污水量集中流量本段流量轉(zhuǎn)輸流量合計(jì)平均流量總變化系數(shù)生活污水設(shè)計(jì)流量本段轉(zhuǎn)輸設(shè)計(jì)流量街坊編號(hào)街坊面積比流量流量31-2354.680.743.470.003.472.358.150.000.008.155-60.690.692.811.941.945-41.481.482.593.833.833-41.481.482.593.833.832-37.787.782.1516.7316.731-232,3512.780.0017.2417.241.9733.9633.961-7317.305.4117.2422.651.9243.4943.4912-130.980.982.712.662.6611-122.902.902.406.966.9610-113.333.332.377.897.899-104.684.682.2810.6710.678-98.718.712.1318.5518.5514-812.8312.832.0426.1726.177-14303.850.742.8522.6525.501.8948.2048.2014-15174.950.743.6638.3341.991.7975.1775.1715-16163.380.742.5041.9944.491.7879.1979.1916-17144.720.743.4944.4947.981.7684.4584.4528-290.550.552.881.581.5827-280.551.992.504.984.9826-271.993.42.368.0272.980.9225-263.405.182.2511.66116.0072.90200.5624-255.186.502.2014.30188.90203.2030-246.508.292.1417.7439.40188.90246.0417-308.2913.162.0326.71228.30255.0117-1882.720.742.0161.1463.151.71107.99228.30336.2923-330.270.273.120.840.8422-230.270.782.772.162.1632-220.780.942.722.562.5621-320.941.252.633.293.2920-211.251.862.524.694.6919-201.865.182.2511.6611.6618-195.187.982.1517.1617.16（4）、水力計(jì)算確定起始管段的管徑以及設(shè)計(jì)流速v，設(shè)計(jì)坡度I，設(shè)計(jì)充滿度h/D：根據(jù)所求得的流量和管徑長度確定管徑的大小和流速、水力坡度、充滿度等?！笆彝馀潘O(shè)計(jì)規(guī)范”規(guī)定城市街道下污水管道最小管徑300mm，它的設(shè)計(jì)最小設(shè)計(jì)流速和最大設(shè)計(jì)充滿度條件下的設(shè)計(jì)流速為26L/s。所以小于此值得流量都取300mm管，與最小設(shè)計(jì)管徑相應(yīng)的最小流速0.6m/s，最小設(shè)計(jì)坡度0.003.設(shè)計(jì)充滿度0.5.查出相應(yīng)的h/D和I的值，若h/D和I值符合設(shè)計(jì)規(guī)范的要求，說明水力計(jì)算合理，將計(jì)算結(jié)果填入污水主干管水力計(jì)算表中相應(yīng)的項(xiàng)中。在水利計(jì)算中，由于Q、v、h/D、I、D各水力因素之間存在相互制約的關(guān)系，因此在查水力計(jì)算圖或表時(shí)實(shí)際存在一個(gè)試算的過程。管段編號(hào)管段長度設(shè)計(jì)流量管段直徑設(shè)計(jì)坡度涉及流速設(shè)計(jì)充滿度降落量h/Dh/m31-2175.008.15300.000.00300.600.500.150.535-6220.001.94300.000.00300.600.500.150.665-4215.003.83300.000.00300.600.500.150.653-4285.003.83300.000.00300.600.500.150.862-3250.0016.73300.000.00300.600.500.150.751-2355.0033.96300.000.00300.750.600.181.071-7230.0043.49350.000.00300.800.550.190.6912-13225.002.66300.000.00300.600.500.150.6811-12100.006.96300.000.00300.600.500.150.3010-11260.007.89300.000.00300.600.500.150.789-10225.0010.67300.000.00300.600.500.150.688-9170.0018.55300.000.00300.600.500.150.5114-8410.0026.17300.000.00300.710.540.161.237-14110.0048.20350.000.00300.820.580.200.3314-15110.0075.17400.000.00320.850.600.240.3515-16295.0079.19400.000.00361.000.600.241.0616-17390.0084.45450.000.00300.970.550.251.1728-29175.001.58300.000.00300.600.500.150.5327-2850.004.98300.000.00300.600.500.150.1526-27160.0080.92450.000.00300.950.530.240.4825-26140.00200.56600.000.00301.150.570.340.4224-25200.00203.20600.000.00301.140.560.340.6030-24330.00246.04700.000.00301.230.520.360.9917-30165.00255.01700.000.00301.240.530.370.5017-18325.00336.29700.000.00341.380.600.421.1123-33100.000.84300.000.00300.600.500.150.3022-23175.002.16300.000.00300.600.500.150.5332-2290.002.56300.000.00300.600.500.150.2721-32140.003.29300.000.00300.600.500.150.4220-21215.004.69300.000.00300.600.500.150.6519-20150.0011.66300.000.00300.600.500.150.4518-1990.0017.16300.000.00300.600.500.150.276、計(jì)算各管段上端、下端的水面、管低標(biāo)高及其埋設(shè)深度：確定管網(wǎng)的控制點(diǎn)?？刂泣c(diǎn)為6、29、33。各節(jié)點(diǎn)標(biāo)高節(jié)點(diǎn)標(biāo)號(hào)節(jié)點(diǎn)高程節(jié)點(diǎn)標(biāo)號(hào)節(jié)點(diǎn)高程節(jié)點(diǎn)標(biāo)號(hào)節(jié)點(diǎn)高程15.00115.40215.1025.20125.41225.5535.70135.58235.9845.80145.08245.5955.85155.10255.6366.10165.33265.6574.98175.24276.1085.07185.03286.1295.40195.05296.20105.60205.08305.30315.80325.35336.30求設(shè)計(jì)管段上、下段的管內(nèi)底標(biāo)高，水面標(biāo)高及埋設(shè)深度。干管埋設(shè)深度如圖：管段編號(hào)管段長度管段直徑降落量標(biāo)高埋設(shè)深度地面水面管內(nèi)底上端下端上端下端上端下端上端下端31-21753000.535.85.24.453.934.33.781.51.435-62203000.666.15.854.754.094.63.941.51.915-42153000.655.855.84.093.453.943.31.912.514-32853000.865.85.73.452.63.32.452.53.263-22503000.755.75.22.61.852.451.73.253.513-122253000.685.585.414.233.564.083.411.52.0111-121003000.35.415.43.563.263.413.1122.2910-112603000.785.45.63.262.483.112.332.293.279-102253000.685.65.42.481.812.331.663.273.758-91703000.515.45.071.811.31.661.153.743.928-144103001.235.075.081.30.071.15-0.083.925.1628-291753000.536.26.124.854.334.74.181.51.9527-28503000.156.126.14.334.184.184.031.942.0726-271604500.486.15.654.183.74.033.552.072.125-261406000.425.655.633.73.283.553.132.12.524-252006000.65.635.593.282.683.132.532.53.0630-243307000.995.595.32.61.612.531.543.063.7617-301657000.55.35.241.611.121.541.053.764.223-331003000.36.35.984.954.654.84.51.51.4822-231753000.535.985.554.654.134.53.981.481.5832-22903000.275.555.354.133.863.983.711.571.6421-321403000.425.355.13.863.443.713.291.641.8120-212153000.655.15.083.442.83.292.651.812.4419-201503000.455.085.052.82.352.652.22.432.8518-19903000.275.055.032.352.082.21.932.853.1主干管的埋設(shè)深度如下圖管段編號(hào)管段長度管段直徑降落量標(biāo)高埋設(shè)深度地面水面管內(nèi)底上端下端上端下端上端下端上端下端7-141103500.335.084.980.09-0.24-0.1-0.435.185.4114-151104000.355.15.08-0.24-0.59-0.48-0.835.585.9115-162954001.065.335.1-0.59-1.65-0.83-1.896.166.9916-173904501.175.245.33-1.6925-2.86-1.94-3.117.188.4417-183257001.115.035.24-1.77-2.88-2.19-3.37.228.547、進(jìn)行管道水力計(jì)算應(yīng)注意的問題：（1）必須細(xì)致研究管道系統(tǒng)的控制點(diǎn)。（2）必須細(xì)致研究管道敷設(shè)坡度與管線經(jīng)過地段的地面坡度之間的關(guān)系。（3）水力計(jì)算自上游依次向下游管段進(jìn)行。（4）地面坡度太大地區(qū)，為減小管內(nèi)水流速度，防止管壁被沖刷，管道坡度往往小于地面坡度。（5）水流經(jīng)過檢查井時(shí)，常引起局部水頭損失。為了盡量降低這項(xiàng)損失，檢查井底部在直線管道上要嚴(yán)格采用直線，在管道轉(zhuǎn)彎處要采用勻稱的曲線。雨水管網(wǎng)設(shè)計(jì)內(nèi)容1、雨水管渠設(shè)計(jì)流量的確定a.雨水管渠設(shè)計(jì)流量計(jì)算公式：式中Q——雨水設(shè)計(jì)流量（L/s）——徑流系數(shù)，其數(shù)值小于1F——匯水面積（ha）q——設(shè)計(jì)暴雨強(qiáng)度（L/（s.ha））b．徑流系數(shù)的確定根據(jù)該地的情況，取徑流系數(shù)=0.60c．設(shè)計(jì)重現(xiàn)期P的確定。假設(shè)取重現(xiàn)期P=1d．集水時(shí)間t的確定式中——地面集水時(shí)間，取=10minm——折減系數(shù)，m=2——管內(nèi)雨水流行時(shí)間=L/v式中L——各管段的長度（m）v——各管段滿流時(shí)的水流速度（m/s）2、雨水管渠水力計(jì)算（1）設(shè)計(jì)充滿度h/D=1（2）設(shè)計(jì)流速雨水管渠的最小設(shè)計(jì)流速應(yīng)大于污水管道，滿流時(shí)管道內(nèi)最小設(shè)計(jì)流速為0.75m/s，金屬管最大流速為10m/s，非金屬管最大流速為5m/s（3）最小管徑和最小設(shè)計(jì)坡度雨水管道的最小管徑為300mm,相應(yīng)的最小坡度為0.003，雨水口連接管徑為200mm,最小坡度為0.01（4）最小埋深與最大埋深具體規(guī)定同污水管道3、雨水管渠的系統(tǒng)的設(shè)計(jì)步驟（1）劃分排水流域和管道定線雨水干管基本垂直于等高線，布置在排水流域地勢(shì)較低的一側(cè)，這樣雨水能以最短距離靠重力流分散就近排入水體。（2）劃分設(shè)計(jì)管段把兩個(gè)檢查井之間流量沒有變化且淤積管徑和坡度也沒有變化的管段定為設(shè)計(jì)管段。（3）劃分并計(jì)算各設(shè)計(jì)管段的匯水面積

各設(shè)計(jì)管段匯水面積的劃分應(yīng)集合地形坡度、匯水面積的大小以及雨水管道布置等情況而劃定。雨水管道布置分五條主管道36-10-2-1,35-1,37-1,9-8-7-6-5-4-3-2-1;39-17-16-15-14-13-12-11-1;40-18,23-22-21-20-19-18;38-34-33-28,32-31-30-29-28;27-26-25-24；雨水管道分布圖見圖紙（4）確定各排水流域的平均徑流系數(shù)值。（5）確定設(shè)計(jì)重現(xiàn)期P、地面集水時(shí)間,則=（6）列表進(jìn)行雨水干管的設(shè)計(jì)流量和水力計(jì)算。（7）繪制雨水管道平面圖雨水管網(wǎng)設(shè)計(jì)計(jì)算4、檢查井標(biāo)高表檢查井編號(hào)地面標(biāo)高檢查井編號(hào)地面標(biāo)高檢查井編號(hào)地面標(biāo)高15.07145.39276.2125.00155.55285.2035.14165.65295.2845.94175.45305.7056.00185.03316.0165.60195.09326.0275.78205.10335.6086.10215.11346.5096.36225.12355.06105.10235.13366.80115.07245.14375.90125.15255.15387.00135.25265.16395.98405.745、每一設(shè)計(jì)管段所承擔(dān)的匯水面積可按就近排入附近雨水管道的原則劃分，然后將每塊匯水面積編號(hào)，計(jì)算數(shù)值。雨水流向標(biāo)注在圖中匯水面積計(jì)算表面積編號(hào)面積面積編號(hào)面積面積編號(hào)面積面積編號(hào)面積面積編號(hào)面積面積編號(hào)面積10.128300.108600.098900.0701200.0691500.05320.137310.036610.105910.0971210.0901510.06530.060320.037620.108920.0831220.1601520.04740.111330.053630.067930.1051230.1161530.13350.195340.038640.030940.1121240.1071540.11460.132350.070650.058950.0901250.0981550.10570.043360.066660.069960.0581260.0931560.11980.129370.066670.097970.0521270.1001570.22090.039380.090680.112980.0541280.0411580.215100.181390.029690.121990.0501290.0361590.233110.108400.021700.0921000.1901300.0501600.202120.128410.025710.1981010.1131310.0561610.138130.103420.034720.1841020.1181320.0891620.137140.140430.043730.1881030.1291330.0451630.146150.108440.044740.0781040.1281340.0431640.172160.088450.041750.0911050.1131350.0471650.210170.088460.047760.1461060.1051360.1551660.043180.116470.087770.1891070.1291370.1471670.078190.139480.086780.1321080.0831380.2231680.083200.114490.089790.0411090.0831390.1441690.116210.113500.079800.0381100.0931400.4221700.090220.125510.093810.0531110.0971410.2561710.072230.145520.076820.0611120.1381420.2721720.068240.109530.116830.1221130.1881430.4261730.055250.120540.108840.0581140.0951450.0581740.050260.154550.099850.0751150.1021460.060260.154560.103860.0901160.0811470.039270.119570.150870.0861170.0861480.061280.125580.134880.0971180.8211490.044290.099590.108890.0491190.1026、雨水干管水力計(jì)算管道編號(hào)管段長度匯水面積管內(nèi)雨水流行時(shí)間t1+t2+5.848單位面積徑流量Qo設(shè)計(jì)流量管徑總t2=L/vt2=L/v12334455636-10425.0000.2840.0008.04910.848200.45556.929300.00010-2490.0000.7328.0509.28026.948107.18578.460350.0009-8250.0000.5250.0004.73510.848200.455105.239400.0007-8200.0001.0504.7353.08620.318130.171136.680400.0006-7180.0001.6267.8212.63226.491108.454176.306450.0005-6270.0002.60610.4534.32731.75495.741249.514500.0004-5230.0003.16414.7803.65140.40881.113256.620500.0003-4380.0003.65618.4315.06747.70972.353264.514500.0003-37195.0000.7510.0002.64210.848200.455150.466400.0002-3165.0004.60923.4972.72357.84363.374292.098600.0001-2250.0005.66626.2203.33363.28859.570337.493600.0001-35260.0000.4550.0004.56110.848200.45591.207350.00039-17130.0000.6090.0002.00610.848200.455122.127400.00016-17100.0001.1082.0061.51514.860161.429178.903400.00015-16120.0001.3863.5211.85217.891142.079196.957500.00014-15175.0001.4895.3732.33321.594124.828185.806400.00013-14125.0001.6647.7071.69426.261109.106181.540400.00012-13380.0002.6279.4005.06729.649100.369263.619500.00011-1295.0003.04414.4671.50839.78281.989249.594500.0001-1195.0003.45515.9751.23742.79877.969269.352500.00038-34170.0000.2270.0003.14810.848200.45545.503250.00033-34200.0000.3243.1483.33317.144146.30647.458250.00028-33250.0000.4106.4814.16723.811116.71247.823250.00031-32185.0000.8160.0002.93710.848200.455163.646450.00030-31195.0001.9202.9372.51916.721148.844285.800500.00029-30175.0002.4615.4562.77821.760124.174305.530600.00028-29190.0004.0858.2342.63927.315106.191433.739700.00022-23160.0000.5640.0002.89910.848200.455113.132400.00021-22165.0000.8752.8992.64416.645149.311130.628400.00020-21200.0001.0835.5433.14521.934123.496133.746400.00019-20215.0001.9758.6873.25828.223103.830205.026500.00018-19240.0002.58411.9453.92234.73890.004232.537500.00040-18190.0000.3050.0003.44210.848200.45561.189300.00027-26220.0000.7200.0003.86010.848200.455144.327450.00025-26275.0001.0953.8603.88418.567138.496151.653450.00024-25190.0001.3487.7443.16726.336108.894146.789450.000流速坡降設(shè)計(jì)地面標(biāo)高設(shè)計(jì)管內(nèi)底標(biāo)高埋深起點(diǎn)終點(diǎn)起點(diǎn)終點(diǎn)起點(diǎn)終點(diǎn)77889910100.881.626.805.105.353.741.451.370.881.475.105.003.742.271.372.740.880.656.366.104.914.26