毕业设计（论文）-某县城市给排水管网工程设计【全套图纸】 46页

目录摘要4ABSTRACT5前言6第一章设计资料6第二章给水管网设计说明与计算82.1给水管网的设计82.1.1给水系统的类型82.1.2给水管网布置的影响因素82.1.3管网系统布置原则92.1.4配水管网布置92.2给水管网设计计算102.2.1设计用水量的组成102.2.2设计用水量的计算102.2.3管网水力计算112.3二级泵站的设计292.3.1水泵选型的原则292.3.2二级泵站流量计算292.3.3二级泵站扬程的确定292.3.4水泵校核302.3.5水泵的选择39第三章排水管网设计说明与计算403.1排水系统的体制及其选择403.2排水系统的布置形式403.3污水管网的布置413.4污水管道系统的设计413.4.1污水管道的定线413.4.2控制点的确定413.4.3污水管道系统设计参数423.4.4污水管道上的主要构筑物433.5污水管道系统水力计算4347\n3.5.1污水流量的计算433.5.2集中流量计算443.5.3污水干管设计流量计算443.5.4污水管道水力计算443.6雨水管渠的设计与计算443.6.1雨水管渠系统的设计步骤443.6.2雨水管道构筑物45结论46总结与体会46谢辞46参考文献47附录47\n摘要本设计是关于四川省某县管网的设计，它包括给水系统，污水排水系统和雨水排水系统三部分。给水系统是通过地形地貌、已知水文条件结合给水管网布置的原则进行设计计算的，并应用管网平差软件来解决计算过程中的难点，最后绘制干管的纵断面图。污水排水系统的设计内容包括排水系统的体制选择、划分排水区域、结合设计要点和自然因素将主干管连入已知污水厂；计算污水设计流量；确定设计参数；绘制管道总平面图和纵断面图。雨水排水系统的设计内容包括划分排水面积，进行雨水管渠定线，定出水口的位置；进行雨水管渠水力计算，确定设计参数；确定管渠总平面图和纵断面图。关键词：给水系统，污水排水系统，雨水排水系统，总平面图，纵断面图全套图纸，加AbstractThedesignisaboutpipelinenetworkofShanyinCounty,SichuanProvince,thepipelinenetworkincludingwatersupplysystem,seweragesystemandrainwaterdischargesystem.Thewatersupplysystemisdesignedandcalculatedundertheprincipleofconsideringterrains47\nandlandforms,knownhydrologicconditionsandlayoutofthepipelinenetworkofwatersupplysystem,withproblemsincalculationsolvedbytheapplicationofpipelinenetworkadjustmentsoftware,andatlast,verticalsectiondrawingofthemainismade.Thedesignoftheseweragesystemincludesselectingdrainagesystems,dividingdrainagearea,connectingthemainintoknownsewageplantwiththeconsiderationofmaindesignpointsandnaturalfactors,computingsewagedesigneddischarge,determiningdesignparameters;andmakingthegeneralplanandverticalsectiondrawingofthepipeline.Thedesignofrainwaterdischargesystemincludesdivisionofdrainagearea,alignmentofrainwaterpipeline,positioningoftheoutlet,hydrauliccalculationofrainwaterpipeline,determinationofdesignparameters,anddeterminationofthegeneralplanandverticalsectiondrawingofthepipeline.Keywords:watersupplysystem,seweragesystem,rainwaterdischargesystem,generalplan,verticalsectiondrawing前言城市给水对人民的生活有着极其重要的影响，它关乎的人们的身体健康，城市排水对受纳水体的水量水质有较大的影响，城市给排水系统已经成为现代城市不可缺少的重要市政基础设施，是城市文明、经济发展和现代化水平的重要标志。给排水管网的主要任务是输送满足人们生活要求的饮用水，供给工厂所需要的水，收集输送人们在生产生活中所排放的污水废水以及城市雨水、冰雪融水，避免排入江河造成水体的污染。在面临全球水资源极其缺乏的今天，给排水管网的作用显得尤为重要。由于城市给排水系统在新的时期赋予了新的内涵，与人们的生产和生活息息相关。看似平凡的规划设计却有着不平凡的现实意义，在满足规范和其它技术要求的条件下，根据城市的具体情况，科学规划设计城市给排水管网系统是一个非常重要的课题。47\n第一章设计资料（1）某县地形平面图一张。（2）该县城位于四川省境内，东部环山，B江在县城中央穿过将其分为南北两部分，总体地形较为平坦，县城总人口20万，设计用水的最小服务水头20m,设计生活用水量定额为300L/cap·d。（3）该县城集中用水单位有6个：化工区24L/s、火车站15L/s、皮毛厂18L/s、针织厂12L/s、棉纺厂12L/s、食品厂12.1L/s。（4）城市自然状况该地区全年温差不大，年平均气温15℃，最高气温32℃，最低气温2℃，夏季主导风向位西北风，土质为黏性土壤。（5）水文资料B江最高洪水位为254m，枯水位为240m，常水位为246m，设计暴雨强度公式：。（6）雨水管网设计计算时生活用水量定额按给水的70%进行计算，集中流量也按照给水集中流量的70%计算。47\n第二章给水管网设计说明与计算2.1给水管网的设计2.1.1给水系统的类型按照城市规划，水源情况，城市地形，用户对水量、水质和水压要求等方面的不同情况，给水系统可有多种布置方式。（1）统一给水系统按照生活饮用水水质标准，有统一管网供给生活、生产和消防用水。（2）分质给水系统对个别用量大，水质要求较低或特殊的工业用水，可单独设置管网供应。（3）分压给水系统根据给水区压力的不同，可采用分压给水系统。（4）分区给水系统地形条件对给水系统的布置很有影响。将给水管网系统划分为多个区域，各区域管网具有独立的供水泵站，供水具有不同的水压。分区给水管网系统可以降低平均供水压力，避免局部水压过高的现象，减少爆管的概率和泵站能量的浪费。（5）工业给水系统47\n综上所述，结合实际情况，该县城有一条水量充沛的河流穿城而过，其水质良好，可以作为生活饮用水水源，该县城地形较为平坦，街区分布比较均匀，各工业企业对水质无特殊要求，因而采用统一给水管网系统。2.1.2给水管网布置的影响因素城市给水管网的布置取决于城市的平面布置、水源、调节构筑物的位置、大用户的分布。考虑的要点有下：（1）城市规划的影响：给水系统的设置，应密切配合城市和工业区的建设规划，做到统盘考虑分期建设，既能及时供应生产生活和消防用水，又能适应今后发展的需要（2）水源的影响：本设计采用地表水并从河流上游取水。2.1.3管网系统布置原则给水管网包括输水管渠和配水管网两大部分。要求能够供给用户所需水量，保证不间断供水，同时要保证配水管网足够的水压。（1）按照城市总体规划，确定给水系统服务范围和建设规模，结合当地实际情况布置给水管网，压进行多方案技术经济比较。（2）分清主次，先进行输水管渠与主干管布置，然后布置一般管线与设施。（3）尽量缩短管线长度，尽量减少拆迁，少占农田，节约工程投资与运行管理费用。（4）协调好与其它管道、电缆和道路等工程的关系。（5）保证供水具有安全可靠性。（6）管渠的施工、运行和维护方便。（7）远近期结合，留有发展余地，考虑分期实施的可能性。2.1.4配水管网布置给水管网遍布整个给水区，根据管道的功能，可划分为干管、分配管、接户管三类。干管的主要作用是输水至城市各用水地区，同时也为沿线用户配水，起管径一般在100mm以上，分配管的主要作用是把干管输送来的谁配给接户管和消火栓，起管径一般不予计算，均由消防流量来确定。干管和分配管的管径并无明确的界限，应视规模确定。干管通常遵循下列原则进行布置：47\n（1）干管布置的主要方向应按供水主要流向眼神，而供水的流向则取决于最大用水户或水塔等调节构筑物的位置。（2）为了保证过供水可靠，通常按照主要流向布置几条平行的干管，其间用连接管连接，这些管线在道路下以最短的距离到达用水量大的主要用户。（3）干管一般按规划道路布置，尽量避免在高级路面或重要道路下敷设。管线在道路下的平面位置和高程应符合城市地下管线综合设计的要求。（4）干管的高处应布置排气阀，低处应设泄水阀，干管上应为安装消火栓预留直观，消火栓的兼具不应大于120m。（5）干管的布置应考虑发展和分期建设的要求，并留有余地。配水管网的布置形式，根据城市规划、用户分布以及用户对用水的安全可靠性的要求程度等，分成树状网和环状网。在本设计中采用的是环状网，当任意一段管线损坏时，闸阀可以将它与其余管线隔开进行检修，不影响其余管线的供水，使供水的地区大为缩小，同时，环状网还可以大大减轻因水锤现象所产生的危害。2.2给水管网设计计算2.2.1设计用水量的组成（1）综合生活用水，包括居民生活用水和公共建筑及设施用水；（2）工业且也生产用水和工作人员生活用水；（3）消防用水；（4）浇洒道路和绿地用水；（5）未预计水量及管网漏失水量。2.2.2设计用水量的计算（1）最高日用水量计算该城镇为中小城市，城市人口20万人，设计生活用水量定额为300L/cap·d,自来水用水普及率为100%。①综合生活用水量式中q——最高日生活用水量定额m³/(d·cap)N——设计年限内计划人口数f——自来水普及率，%。47\n则①工业生产用水量②浇洒道路和绿地用水③管网漏失水量⑤最高日用水量（2）最高日平均时用水量（3）最高日最高时用水量（4）清水池容积计算式中：W1——调节容积，m³；按最高日用水量的20%估算W2——消防贮水量，m³，按2～3h火灾延续时间计算，本设计采用2h一次用水量45L/sW3——水厂冲洗滤池和沉淀池排泥等生产用水，m³，等于最高日用水量的5%～10%W4——安全储量，m³，为避免清水池抽空，清水池可保留一定水深（0.5m）作为安全储量则47\n2.2.3管网水力计算（1）比流量计算城镇供水区总面积∑A=305.7ha，其中水厂到节点1管段两侧无用户。（2）沿线流量计算各管段沿线流量见表2.1。表2.1管段沿线流量管段编号街区面积（ha)比流量（l/s.ha）沿线流量（l/s）1--20.564.152.321--61.764.157.301--201.574.156.522--30.864.153.573--40.944.153.903--61.124.154.654--50.84.153.324--71.24.154.985--80.644.152.666--72.284.159.466--192.274.159.427--82.94.1512.048--90.724.152.998--172.64.1510.799--101.14.154.579--163.144.1513.0310--110.064.150.2510--152.934.1512.1611--141.574.156.5213--141.44.155.8113--280.724.152.9914--151.664.156.8914--271.444.155.9815--161.064.154.4015--261.444.155.9816--170.744.153.0747\n16--251.444.155.9817--180.744.153.0717--241.444.155.9818--190.974.154.0318--231.444.155.9819--200.894.153.69续表119--221.444.155.9820--210.724.152.9921--221.794.157.4321--371.284.155.3122--231.944.158.0522--361.584.156.5623--241.54.156.2323--352.34.159.5524--251.464.156.0624--342.54.1510.3825--262.164.158.9625--331.554.156.4326--273.544.1514.6926--322.64.1510.7927--282.964.1512.2827--312.54.1510.3828--301.334.155.5229--301.434.155.9329--462.14.158.7230--312.84.1511.6230--453.94.1516.1931--323.464.1514.3631--443.744.1515.5232--332.24.159.1332--433.794.1515.7333--341.444.155.9833--423.54.1514.5334--351.254.155.1934--413.584.1514.8635--362.154.158.9235--403.134.1512.9936--371.84.157.4736--393.274.1513.5737--381.84.157.4738--390.874.153.6139--400.824.153.4047\n40--410.674.152.7841--420.724.152.99续表242--431.14.154.5743--441.964.158.1344--451.44.155.8145--461.44.155.8147--4814.154.1547--680.724.152.9948--491.24.154.9848--671.444.155.9849--500.814.153.3649--661.444.155.9850--511.064.154.4050--651.444.155.9851--521.24.154.9851--641.444.155.9852--531.94.157.8952--631.444.155.9853--542.064.158.5553--621.444.155.9854--551.84.157.4754--611.444.155.9855--561.154.154.7755--601.444.155.9856--570.984.154.0756--591.254.155.1957--580.044.150.1757--811.064.154.4058--591.934.158.0158--791.264.155.2359--602.34.159.5559--781.444.155.9860--613.64.1514.9460--771.444.155.9861--624.124.1517.1061--761.444.155.9862--633.84.1515.7762--751.444.155.9863--642.44.159.9663--741.444.155.9847\n续表364--652.124.158.8064--731.444.155.9865--661.624.156.7265--721.444.155.9866--672.44.159.9666--711.444.155.9867--6824.158.3067--701.444.155.9868--690.724.152.9969--7024.158.3069--930.724.152.9970--712.44.159.9670--921.444.155.9871--721.624.156.7271--911.444.155.9872--732.124.158.8072--901.444.155.9873--742.44.159.9673--891.444.155.9874--753.84.1515.7774--881.444.155.9875--764.124.1517.1075--871.444.155.9876--773.64.1514.9476--861.444.155.9877--782.34.159.5577--851.444.155.9878--792.34.159.5578--841.444.155.9879--802.094.158.6779--831.444.155.9880--810.064.150.2580--820.724.152.9982--832.464.1510.2182--1051.444.155.9883--842.34.159.5583--1041.444.155.9884--852.34.159.55续表447\n84--1031.444.155.9885--863.64.1514.9485--1021.444.155.9886--874.124.1517.1086--1011.444.155.9887--883.84.1515.7787--1001.444.155.9888--892.44.159.9688--991.444.155.9889--902.124.158.8089--981.444.155.9890--911.624.156.7290--971.444.155.9891--922.44.159.9691--961.444.155.9892--9324.158.3092--951.444.155.9893--940.724.152.9994--9514.154.1595--961.24.154.9896--970.814.153.3697--981.064.154.4098--991.24.154.9899--1001.94.157.89100--1012.064.158.55101--1021.84.157.47102--1031.154.154.77103--1041.154.154.77104--1051.234.155.10（1）节点流量计算，其中节点2，9，11，12，13，29有集中流量，分别为24L/s、15L/s、12.1L/s、12L/s、12L/s、18L/s。各节点流量见表2.2。表2.2节点流量节点节点流量L/s集中流量L/s最终节点流量L/s18.07　8.0747\n22.9452426.9536.06　6.0646.1　6.1052.99　2.99615.415　15.42713.24　13.24814.24　14.24910.2951525.30108.49　8.49113.38512.115.491201212.00134.41216.401412.6　12.601514.715　14.721613.24　13.241711.455　11.46186.54　6.541911.56　11.56204.755　4.76217.865　7.872214.01　14.012314.905　14.912414.325　14.332513.715　13.722620.21　20.212721.665　21.672810.395　10.40297.3251825.33续表13019.63　19.633125.94　25.943225.005　25.013318.035　18.043418.205　18.2147\n3518.325　18.333618.26　18.263710.125　10.13385.54　5.543910.29　10.29409.585　9.594110.315　10.324211.045　11.054314.215　14.224414.73　14.734513.905　13.91467.265　7.27473.57　3.57487.555　7.56497.16　7.16506.87　6.87517.68　7.68529.425　9.435311.21　11.215411　11.00559.11　9.11567.015　7.02574.32　4.32586.705　6.715911.77　11.77续表26018.225　18.236122　22.006222.415　22.426318.845　18.856415.36　15.366513.74　13.746614.32　14.326713.12　13.1247\n687.14　7.14694.485　4.497015.11　15.117114.32　14.327213.74　13.747315.36　15.367418.845　18.857522.415　22.427623.345　23.357718.225　18.237815.53　15.537914.715　14.72805.955　5.96812.325　2.33829.59　9.598315.86　15.868415.53　15.538518.225　18.238622　22.008722.415　22.428818.845　18.858915.36　15.36续表39013.74　13.749114.32　14.329215.11　15.11939.795　9.80943.57　3.57957.555　7.56967.16　7.16976.87　6.87987.68　7.68999.425　9.4310011.21　11.2147\n10111　11.001029.11　9.111037.76　7.761047.925　7.931055.54　5.54（1）管网平差管网平差的步骤：①选取海曾-威廉公式，阻力系数取110；②节点数据输入地面标高，已知水压，已知流量；③管段数据输入管径，起始终止节点，长度，阻力系数；其后进行管网平差，使得数据处于经济流速范围内。经济流速见表2.3。表2.3给水经济流速管径（mm）D=100～400D≥400平均经济流速（m/s）0.6～0.90.9～1.4④导出管网平差结果，见表2.4和表2.5。表2.4管网平差节点水压编号地面标高已知水压已知流量节点水压自由水头节点流量1254.8285　28530.2-1349.112254.9　26.95284.496929.596926.953254.7　6.06283.043428.34346.064254.7　6.1282.409327.70936.15254.5　2.99282.303727.80372.996254.8　15.42284.130629.330615.427254.6　13.24283.491228.891213.248253.9　14.24282.55128.65114.249252.9　25.3281.986829.086825.310252.5　8.49280.878928.37898.4911252.4　15.49280.393327.993315.4912251.5　12273.127421.62741247\n13251　16.4275.692224.692216.414251　12.6278.44427.44412.615252.3　14.72278.246625.946614.7216253　13.24278.921325.921313.2417253.6　11.46280.079726.479711.4618254.9　6.54281.398926.49896.5419254.6　11.56282.519627.919611.5620254.7　4.76284.692529.99254.7621254.8　7.87284.490729.69077.8722254.5　14.01284.272229.772214.0123255.2　14.91284.046728.846714.9124253.2　14.33282.091428.891414.3325253　13.72281.090228.090213.7226253　20.21279.873926.873920.2127250.7　21.67279.489628.789621.6728252　10.4277.785225.785210.429256　25.33278.821722.821725.33续表130252.8　19.63279.449626.649619.6331250.4　25.94280.254529.854525.9432252　25.01281.261829.261825.0133253.2　18.04282.070428.870418.0434254　18.21282.983628.983618.2135254.7　18.33283.440528.740518.3336254.7　18.26281.30226.60218.2637254.6　10.13283.428728.828710.1338254　5.54281.432827.43285.5439253　10.29281.503528.503510.2940252.2　9.59282.879130.67919.5941252.8　10.32281.488828.688810.3242253　11.05278.842825.842811.0543253　14.22278.729525.729514.2244253　14.73278.177425.177414.7345252　13.91277.283225.283213.9147\n46254.9　7.27277.19822.2987.2747250.5　3.57275.669625.16963.5748251　7.56278.100827.10087.5649250.7　7.16279.753629.05367.1650250.8　6.87280.474929.67496.8751250　7.68281.173731.17377.6852249.5　9.43282.09332.5939.4353249.7　11.21280.857131.157111.2154250.4　11280.002929.60291155250.8　9.11278.703227.90329.1156250　7.02277.944927.94497.0257251.1　4.32276.942425.84244.3258251.4　6.71276.798525.39856.7159252.2　11.77276.080923.880911.77续表260252.6　18.23278.040625.440618.2361252.3　22279.376427.07642262251.9　22.42280.024328.124322.4263252.1　18.85281.169229.069218.8564252.2　15.36279.656927.456915.3665251.6　13.74279.937528.337513.7466251.3　14.32279.226527.926514.3267251　13.12278.135227.135213.1268250.6　7.14275.209224.60927.1469249.7　4.49274.911225.21124.4970249.7　15.11277.919828.219815.1171250.8　14.32278.772827.972814.3272251.7　13.74279.32727.62713.7473252.6　15.36278.393925.793915.3674253.1　18.85280.585927.485918.8575253　22.42278.068325.068322.4276253.1　23.35278.647425.547423.3577253.2　18.23277.385824.185818.2378252.5　15.53275.099222.599215.5347\n79252.2　14.72276.372724.172714.7280251.3　5.96273.275121.97515.9681251.1　2.33273.677222.57722.3382251.6　9.59272.1920.599.5983252.2　15.86275.411523.211515.8684252.7　15.53273.477920.777915.5385253.3　18.23275.708822.408818.2386254.2　22278.276424.07642287254.8　22.42278.014223.214222.4288252.8　18.85279.907127.107118.8589252.1　15.36278.761626.661615.36续表390250.9　13.74278.664227.764213.7491250.2　14.32277.839627.639614.3292250.1　15.11276.26526.16515.1193249.7　9.8273.652223.95229.894249.6　3.57273.592523.99253.5795249.7　7.56274.138824.43887.5696249.7　7.16275.688725.98877.1697249.9　6.87277.647527.74756.8798250.6　7.68277.709127.10917.6899252.4　9.43279.321826.92189.43100254.7　11.21276.91622.21611.21101254.7　11277.704923.004911102253.7　9.11276.603122.90319.11103252.9　7.76273.491820.59187.76104252.1　7.93273.853121.75317.93105251.6　5.54272.12420.5245.54表2.5管网平差管段编号管径长度阻力系数起始节点终止节点流量流速水力坡度水头损失10.25200.21101231.57510.64322.5130.503120.423411016134.2071.0683.71530.869431.2309.51101201183.3281.04630.99350.307547\n40.1234110234.62510.58896.21131.453550.1247.6110342.86660.3652.5610.634160.1200.211036-4.30150.54775.4305-1.087270.1261.8110451.05660.13450.40330.105680.1200.211047-4.290.54625.4038-1.081890.1200.211058-1.93340.24621.235-0.2472100.4247.611067110.28130.87762.58260.6395110.1309.51106194.20420.53535.20521.611续表1120.35261.81107892.75130.9643.59130.9402130.35255.81108971.28110.74092.20540.5641140.1309.51108175.29680.67447.98472.4713150.25284.111091040.03070.81553.89981.1079160.1309.51109165.95050.75769.90493.0656170.293110101126.06020.82955.2210.4856180.1309.511010155.48050.69788.50512.6323190.1415.611011143.97430.5064.69051.9494200.1606.211011126.59590.839811.9867.2659210.1309.51101213-5.40410.68818.2869-2.5648220.15328.81101314-15.77920.89298.369-2.7517230.1206.51101328-6.02490.767110.1356-2.093240.1370.411014151.22810.15640.53290.1974250.2206.51101427-25.6330.81595.0636-1.0456260.1284.11101516-2.75210.35042.3748-0.6747270.1206.51101526-5.25940.66967.8805-1.6273280.1255.81101617-3.89970.49654.5287-1.1584290.1206.51101625-6.14190.78210.5031-2.1689300.1257.81101718-4.16560.53045.117-1.3192310.1206.51101724-5.89730.75099.7418-2.0117320.1251.61101819-3.8650.49214.4544-1.1207330.1206.51101823-6.84050.87112.8223-2.6478340.12341101920-5.74670.73179.2859-2.1729350.1206.51101922-5.47420.6978.487-1.752647\n361.2206.511020211172.8211.0370.97720.2018371.223411021221144.5051.0120.9340.2185380.2318.8110213720.44590.65083.33131.062391.2251.611022231119.2640.98960.89620.2255400.1318.811022365.7570.7339.31672.9702410.25257.8110232457.32971.16797.58461.9553续表2421318.811023351040.1841.32441.90140.6062430.25255.8110242540.10960.81713.91411.0012440.1318.81102434-3.00730.38292.7987-0.8922450.2284.1110252623.41170.74524.28111.2163460.1318.81102533-3.16390.40283.0747-0.9802470.1370.411026271.75990.22411.03750.3843480.1318.81102632-3.81750.48614.3536-1.3879490.1328.811027284.19470.53415.18361.7044500.3318.81102731-49.73780.70362.3992-0.7649510.15318.81102830-12.23020.69215.2209-1.6644520.25283.81102930-29.47660.60052.2125-0.6279530.132011029464.14670.5285.07411.6237540.35328.81103031-75.40910.78382.4477-0.8048550.15320110304514.07240.79636.77012.1664560.45328.81103132-164.8431.03653.0637-1.0074570.15320110314413.7560.77846.49092.0771580.5284.11103233-208.981.06432.846-0.8085590.15320110324315.30960.86637.91362.5323600.5255.81103334-236.1931.20293.5702-0.9133610.132011033426.0090.765110.08613.2275620.6257.81103435-261.3760.92441.7724-0.4569630.132011034413.96550.50494.67121.4948640.1251.611035365.47860.69768.49972.1385650.93201103540754.9991.18681.75460.5615660.12341103637-5.68040.72339.0885-2.1267670.13201103639-1.3440.17110.6297-0.2015680.132011037384.63550.59026.23741.99647\n690.12341103839-0.90450.11520.3024-0.0708700.15251.61103940-12.53840.70955.4672-1.3755710.15257.8110404112.44590.70435.39281.3903续表3720.9488.61104052720.42471.13241.60870.786730.1255.811041426.09150.775610.3442.646740.1284.111042431.05050.13370.3990.1134750.1370.411043442.14010.27251.49050.5521760.1328.811044452.9610.3772.71940.8941770.1488.61104455-1.79490.22851.0761-0.5258780.128.3811045463.12330.39773.00210.0852790.1237.21104748-6.06150.771810.2498-2.4313800.1233.111047682.49150.31721.97520.4604810.15282.41104849-13.00830.73615.8527-1.6528820.1233.11104867-0.61310.07810.1472-0.0343830.4228.81104950-122.8180.97743.1526-0.7213840.4233.11104966102.64980.81692.26140.5271850.5259.81105051-202.71.03232.6896-0.6988860.35233.1110506573.01240.75892.30560.5374870.5283.71105152-224.1551.14163.2405-0.9193880.15233.1110516413.77480.77956.50731.5169890.6410.71105253347.86711.23033.00941.236900.4233.11105263138.9721.10593.96330.9238910.6376.91105354298.47741.05562.26630.8542920.25233.1110536238.17990.77783.57250.8328930.45380.61105455174.79231.0993.4151.2997940.4233.11105461112.68510.89672.68790.6265950.4298.11105556109.38190.87042.54380.7583960.3233.1110556054.50560.77112.84240.6626970.35314.5110565786.96610.90393.18751.0025980.15233.1110565915.39590.87127.99631.8639990.3557110575876.67260.79692.52420.14391000.1327.311057815.97350.76069.97623.26521010.1267.111058592.94160.37452.68660.717647\n续表41020.35216.4110587967.0210.69661.96750.42581030.1298.11105960-4.76890.60726.5739-1.95971040.15216.4110597811.33650.64154.53640.98171050.1380.61106061-3.39820.43273.5097-1.33581060.25216.4110607734.90490.71113.02580.65481070.1376.91106162-2.31150.29431.7192-0.6481080.35216.4110617689.59840.93133.36850.72891090.1410.71106263-3.00080.38212.7877-1.14491100.15216.4110627516.44920.93089.0391.9561110.1283.711063644.25870.54225.33081.51241120.4216.41106374112.86250.89812.69570.58341130.1259.81106465-1.79860.2291.0803-0.28071140.1216.411064734.47210.56945.83611.26291150.1228.211065663.18670.40573.11580.7111160.3216.4110657254.28710.7682.82140.61051170.2282.4110666722.15270.70513.86451.09131180.35216.4110667169.36370.7212.09680.45371190.1237.211067686.6990.852912.33552.9261200.1216.411067701.72060.21910.9950.21531210.1216.411068692.05050.26111.37710.2981220.1237.21106970-6.80060.865912.6841-3.00871230.122611069934.36110.55535.57081.2591240.25282.41107071-34.87070.71043.0203-0.85291250.15226110709214.68070.83087.3221.65481260.1228.21107172-2.78560.35472.4286-0.55421270.2226110719122.95860.73084.12890.93311280.1259.811072733.44070.43813.59140.9331290.25226110729034.32080.69922.93270.66281300.1283.71107374-5.20350.66257.7263-2.19191310.12261107389-2.24360.28571.6269-0.3677续表51320.1410.711074754.59230.58476.12992.51761330.35226110748884.21670.87533.00340.678847\n1340.1376.91107576-2.17550.2771.5366-0.57911350.122611075870.7970.10150.23930.05411360.1380.611076773.2950.41953.31481.26161370.35226110768660.77780.63171.64160.3711380.1298.111077785.18320.65997.67052.28661390.15226110778514.78670.83687.42031.6771400.1267.11107879-4.00960.51054.7679-1.27351410.122611078844.99930.63657.1741.62131420.127811079806.34110.807411.14283.09771430.25226110798341.95020.85464.25320.96121440.1100.71108081-3.64350.46393.9933-0.40211450.122611080824.02470.51244.80111.08511460.12781108283-6.47670.824611.5882-3.22151470.1215.3110821050.91140.1160.30670.0661480.1267.111083845.02380.63977.23931.93361490.15215.31108310414.58970.82567.23821.55841500.1298.11108485-5.11470.65127.4837-2.23091510.1215.311084103-0.39220.04990.0643-0.01391520.1380.61108586-4.83610.61576.7462-2.56761530.1215.311085102-3.72190.47394.1537-0.89431540.1376.911086871.41820.18060.69570.26221550.25215.31108610132.52360.66262.65460.57151560.2410.71108788-24.36320.77554.6089-1.89291570.1215.3110871004.15840.52955.10071.09821580.2283.7110888922.68340.7224.03781.14551590.2215.3110889918.32010.58312.71840.58531600.1259.811089901.01580.12930.3750.09741610.1215.311089984.0640.51754.88851.0525续表61620.15228.8110909110.01180.56663.60380.82461630.15215.3110909711.58480.65564.72211.01671640.15282.4110919212.67220.71715.57571.57461650.1215.311091965.97820.76129.99052.1511660.1237.211092936.30190.802411.01552.612947\n1670.1215.311092955.9410.75649.87562.12621680.1215.311093940.8630.10990.27730.05971690.1237.21109495-2.7070.34472.3033-0.54631700.1282.41109596-4.3260.55085.4881-1.54981710.1228.21109697-5.50790.70138.5839-1.95881720.1259.81109798-0.79310.1010.2371-0.06161730.1283.71109899-4.4090.56145.6847-1.61271740.1410.7110991004.4810.57055.85782.40581750.1376.9110100101-2.57060.32732.093-0.78881760.2380.611010110218.9530.60332.89481.10181770.1298.11101021036.12110.779410.43733.11131780.1267.1110103104-2.03110.25861.353-0.36141790.12781101041054.62860.58936.221.72922.3二级泵站的设计2.3.1水泵选型的原则水泵选型是根据所需设计流量与设计扬程选泵，所选水泵应满足以下要求：（1）在满足设计流量与设计扬程的情况下，应适应工况变化，即工况变化时，扬程浪费较小；（2）在长期运行中平均工作效率高，既是选用效率较高的泵，运行时能使工况点落在高效段；（3）水泵汽蚀性能良好，即选用允许吸上真空高度HS较大，必须汽蚀余量[NPSH]r较小的泵；（4）所配电动机总装机容量小，避免“小马拉大车”；（5）结构合理，便于安装、维护和管理；（6）泵站投资小。2.3.2二级泵站流量计算47\n二级泵站的计算流量与管网只能够是否设置水塔或高地水池有关。当管网内不设水塔时，任何小时的二级泵站供水量应等于用水量，这事二级泵站应满足最高日最高时的水量要求，否则就会存在不同程度的供水不足的现象。因为用水量每日每小时都在变化。故在本设计题目中流量为1362.76L/s。2.3.3二级泵站扬程的确定在本设计中没有水塔，水泵的净扬程等于管网控制点的水压标高与清水池最低水位之间的高程差，管网控制点88在该县城北面，其地面标高为253m，清水池最低水面标高为252.8m，最小服务水头为20m，水损取1—20—21—23—35—40—52—63—74—88，安全水头取2m，吸水管和泵房内的水头损失为2m，清水池水深取5m。从泵站到节点1的输水管有2条，每条输水管的长度为321.6m每条输水管输送水的流量为,选择800mm管径，其水头损失为:。则水泵扬程：2.3.4水泵校核消防时的管网校核，是以最高时确定管径来进行的，按照最高用水时另外增加消防设施时的流量进行流量分配，在节点88（控制点）和节点9各加45L/s的消防用水，算出各管段消防时的流量和水头损失。消防时控制点88的服务水头为10m，水损取1—20—21—23—35—40—52—63—74—88，吸水管和泵房内的水头损失为2m，则消防时的水泵扬程为：所以满足要求,故不需要设置消防泵。消防校核后各节点的自由水头和各管段的水头损失见表2.6和表2.7。表2.6消防校核自由水头47\n编号地面标高已知水压已知流量节点水压自由水头节点流量1254.8285　28530.2-1439.112254.9　26.95284.470429.570426.953254.7　6.06282.459327.75936.064254.7　6.1281.309426.60946.15254.5　2.99280.797226.29722.996254.8　15.42283.641928.841915.427254.6　13.24282.553227.953213.248253.9　14.24280.818326.918314.249252.9　70.3279.553326.653370.310252.5　8.49278.659426.15948.4911252.4　15.49278.264325.864315.4912251.5　12272.017520.51751213251　16.4275.05524.05516.414251　12.6277.839326.839312.615252.3　14.72277.295224.995214.7216253　13.24277.878824.878813.2417253.6　11.46279.261625.661611.4618254.9　6.54281.008126.10816.5419254.6　11.56282.272727.672711.5620254.7　4.76284.666729.96674.7621254.8　7.87284.44829.6487.8722254.5　14.01284.210729.710714.01续表123255.2　14.91283.965528.765514.9124253.2　14.33281.86428.66414.3325253　13.72280.790627.790613.7226253　20.21279.508326.508320.2127250.7　21.67279.141528.441521.6728252　10.4277.423625.423610.429256　25.33278.561822.561825.3330252.8　19.63279.189826.389819.6331250.4　25.94280.002629.602625.9432252　25.01281.052729.052725.0147\n33253.2　18.04281.890228.690218.0434254　18.21282.83428.83418.2135254.7　18.33283.305428.605418.3336254.7　18.26281.182126.482118.2637254.6　10.13283.368328.768310.1338254　5.54281.293227.29325.5439253　10.29281.350428.350410.2940252.2　9.59282.68130.4819.5941252.8　10.32281.29828.49810.3242253　11.05278.632925.632911.0543253　14.22278.508625.508614.2244253　14.73277.911824.911814.7345252　13.91277.021825.021813.9146254.9　7.27276.936722.03677.2747250.5　3.57275.232424.73243.5748251　7.56277.682126.68217.5649250.7　7.16279.351828.65187.1650250.8　6.87280.091829.29186.8751250　7.68280.829630.82967.6852249.5　9.43281.801932.30199.43续表253249.7　11.21280.532930.832911.2154250.4　11279.662629.26261155250.8　9.11278.360127.56019.1156250　7.02277.600527.60057.0257251.1　4.32276.596325.49634.3258251.4　6.71276.452125.05216.7159252.2　11.77275.732323.532311.7760252.6　18.23277.691925.091918.2361252.3　22279.006826.70682262251.9　22.42279.618127.718122.4263252.1　18.85280.431728.331718.8564252.2　15.36279.134726.934715.3665251.6　13.74279.49427.89413.7447\n66251.3　14.32278.808927.508914.3267251　13.12277.711726.711713.1268250.6　7.14274.763524.16357.1469249.7　4.49274.451324.75134.4970249.7　15.11277.476627.776615.1171250.8　14.32278.336727.536714.3272251.7　13.74278.794627.094613.7473252.6　15.36277.440724.840715.3674253.1　18.85279.48426.38418.8575253　22.42277.306324.306322.4276253.1　23.35278.235625.135623.3577253.2　18.23277.029423.829418.2378252.5　15.53274.746822.246815.5379252.2　14.72276.025423.825414.7280251.3　5.96272.925821.62585.9681251.1　2.33273.328422.22842.3382251.6　9.59271.838320.23839.59续表383252.2　15.86275.061522.861515.8684252.7　15.53273.108820.408815.5385253.3　18.23275.321322.021318.2386254.2　22277.839223.63922287254.8　22.42276.810422.010422.4288252.8　63.85278.20525.40563.8589252.1　15.36277.508825.408815.3690250.9　13.74277.99627.09613.7491250.2　14.32277.320427.120414.3292250.1　15.11275.775625.675615.1193249.7　9.8273.153223.45329.894249.6　3.57273.082123.48213.5795249.7　7.56273.597123.89717.5696249.7　7.16275.040425.34047.1697249.9　6.87276.772326.87236.8798250.6　7.68276.712426.11247.6847\n99252.4　9.43277.710925.31099.43100254.7　11.21275.861721.161711.21101254.7　11277.244122.544111102253.7　9.11276.163122.46319.11103252.9　7.76273.120720.22077.76104252.1　7.93273.496121.39617.93105251.6　5.54271.771420.17145.54表2.7管段水头损失编号管径长度阻力系数起始节点终止节点流量流速水力坡度水头损失10.25200.21101232.46160.66132.64530.529620.423411016170.7571.35885.80381.358131.2309.51101201235.8911.09281.07680.333340.1234110235.51160.70188.59462.0111续表150.1247.6110343.9530.50334.6441.149860.1200.211036-4.50140.57315.9072-1.182670.1261.8110452.47870.31561.95650.512280.1200.211047-4.62570.5896.2129-1.243890.1200.211058-0.51130.06510.1052-0.0211100.4247.611067146.98491.16974.39681.0887110.1309.51106193.85060.49034.42381.3692120.35261.811078129.11911.3426.62711.735130.35255.811089110.24091.14584.94531.265140.1309.51108174.1270.52555.02961.5567150.25284.111091035.64820.72623.14620.8938160.1309.51109164.29280.54665.41031.6745170.293110101123.31510.74214.24850.3951180.1309.511010153.84310.48934.40771.3642190.1415.611011141.74610.22231.02260.425200.1606.211011126.0790.77410.30486.2468210.1309.51101213-5.92090.75399.8141-3.0375220.15328.81101314-15.87990.89868.4682-2.784347\n230.1206.51101328-6.44110.820111.4702-2.3686240.1370.411014152.12330.27031.46890.5441250.2206.51101427-28.85710.91866.306-1.3022260.1284.11101516-2.54460.3242.0539-0.5835270.1206.51101526-6.2090.790610.7168-2.213280.1255.81101617-4.29090.54635.4059-1.3828290.1206.51101625-7.20080.916814.1011-2.9119300.1257.81101718-4.8470.61716.7746-1.7465310.1206.51101724-6.77690.862912.6025-2.6024320.1251.61101819-4.12560.52535.0265-1.2647330.1206.51101823-7.26140.924614.3217-2.9574340.12341101920-6.05540.77110.2307-2.394续表2350.1206.51101922-5.77960.73599.3846-1.9379361.2206.511020211225.0751.08321.05940.2188371.223411021221196.5761.0581.01420.2373380.2318.8110213720.62940.65673.38681.0797391.2251.611022231170.9691.03540.97440.2451400.1318.811022365.81780.74079.49973.0285410.25257.8110232459.60581.21438.15172.1015421318.811023351089.1921.38682.07060.6601430.25255.8110242541.6450.84844.19611.0734440.1318.81102434-3.14610.40063.0427-0.97450.2284.1110252624.09060.76684.51391.2824460.1318.81102533-3.36640.42863.449-1.0995470.1370.411026271.71590.21850.99010.3667480.1318.81102632-4.04430.51494.8446-1.5445490.1328.811027284.21270.53645.22481.7179500.3318.81102731-53.02390.75012.701-0.8611510.15318.81102830-12.62830.71465.54-1.7662520.25283.81102930-29.47850.60052.2128-0.628530.132011029464.14860.52825.07841.6251540.35328.81103031-75.81470.7882.4721-0.8128550.15320110304514.07780.79666.7752.16847\n560.45328.81103132-168.5831.063.1937-1.0501570.15320110314413.80490.78126.53372.0908580.5284.11103233-212.9861.08472.9478-0.8375590.15320110324315.3480.86857.95032.5441600.5255.81103334-240.4311.22453.6897-0.9438610.132011033426.03880.768910.17913.2573620.6257.81103435-265.8110.94011.8285-0.4714630.132011034414.02420.51244.80021.5361640.1251.611035365.45750.69498.4392.1233续表3650.93201103540799.59281.25691.95130.6244660.12341103637-5.76550.73419.3423-2.1861670.13201103639-1.21920.15520.5258-0.1683680.132011037384.73380.60276.48452.075690.12341103839-0.80620.10260.2444-0.0572700.15251.61103940-12.31540.69695.2884-1.3306710.15257.8110404112.41090.70235.36471.383720.9488.61104052765.27661.20291.79910.879730.1255.811041426.11510.778610.41862.6651740.1284.111042431.1040.14060.43750.1243750.1370.411043442.2320.28421.61120.5968760.1328.811044452.95360.37612.70690.89770.1488.61104455-1.64680.20970.9174-0.4483780.128.3811045463.12140.39742.99870.0851790.1237.21104748-6.08620.774910.3275-2.4497800.1233.111047682.51620.32042.01180.4689810.15282.41104849-13.07990.74025.9125-1.6697820.1233.11104867-0.56630.07210.1271-0.0296830.4228.81104950-124.530.9913.2344-0.74840.4233.11104966104.29020.82992.32880.5429850.5259.81105051-208.7351.06312.8398-0.7378860.35233.1110506577.33530.80382.56480.5978870.5283.71105152-231.0411.17673.4273-0.9723880.15233.1110516414.62560.82767.27121.694947\n890.6410.71105253352.86861.2483.09011.2691900.4233.11105263171.93671.36825.87831.3702910.6376.91105354301.49211.06632.30890.8702920.25233.1110536240.16660.81833.92440.9148930.45380.61105455174.99571.10033.42241.3025940.4233.11105461115.49640.91912.81340.6558续表4950.4298.11105556109.48340.87122.54810.7596960.3233.1110556054.75570.77462.86660.6682970.35314.5110565787.04860.90483.19311.0042980.15233.1110565915.41480.87238.01461.8682990.3557110575876.75250.79772.52910.14421000.1327.311057815.97610.76099.98423.26781010.1267.111058592.94650.37522.69490.71981020.35216.4110587967.0960.69741.97160.42661030.1298.11105960-4.76880.60726.5736-1.95961040.15216.4110597811.36020.64294.5540.98551050.1380.61106061-3.36950.4293.455-1.3151060.25216.4110607735.12640.71563.06150.66251070.1376.91106162-2.23980.28521.6218-0.61121080.35216.4110617692.36670.963.56370.77121090.1410.71106263-2.49540.31771.9811-0.81361100.15216.4110627518.00221.018710.68282.31171110.1283.711063643.91970.49914.57171.2971120.4216.41106374146.67161.16724.37950.94771130.1259.81106465-2.05520.26171.3829-0.35931140.1216.411064735.24050.66727.82811.6941150.1228.211065663.12330.39773.00190.6851160.3216.4110657258.41680.82643.23170.69931170.2282.4110666722.21690.70723.88531.09721180.35216.4110667170.87650.73672.18220.47221190.1237.211067686.72650.856412.42942.94831200.1216.411067701.80410.22971.08640.23511210.1216.411068692.10280.26771.44270.312247\n1220.1237.21106970-6.82090.868512.7545-3.02541230.122611069934.43370.56455.74381.29811240.25282.41107071-35.02780.71363.0456-0.8601续表51250.15226110709214.9010.84327.52691.70111260.1228.21107172-2.51290.31992.0068-0.45791270.2226110719124.04150.76534.49681.01631280.1259.811072734.20690.53565.21151.3541290.25226110729037.9570.77333.5340.79871300.1283.71107374-5.00990.63797.2023-2.04331310.12261107389-0.90270.11490.3013-0.06811320.1410.711074754.24630.54075.30232.17771330.352261107488118.56531.23235.6591.27891340.1376.91107576-2.80840.35762.4657-0.92931350.122611075872.6370.33582.19420.49591360.1380.611076773.21620.40953.16941.20631370.35226110768662.99210.65471.75410.39641380.1298.111077785.17830.65937.65712.28261390.15226110778514.93420.84517.5581.70811400.1267.11107879-4.01840.51164.7872-1.27871410.122611078845.0270.64017.24771.6381420.127811079806.34330.807711.14993.09971430.25226110798342.01430.85594.26530.9641440.1100.71108081-3.64610.46423.9985-0.40261450.122611080824.02940.5134.81171.08741460.12781108283-6.47850.824911.5941-3.22321470.1215.3110821050.9180.11690.31080.06691480.1267.111083845.05050.64317.31071.95271490.15215.31108310414.62530.82767.27091.56541500.1298.11108485-5.09180.64837.4219-2.21251510.1215.311084103-0.36070.04590.0551-0.01191520.1380.61108586-4.78530.60936.6157-2.51791530.1215.311085102-3.60230.45873.9099-0.84181540.1376.911086872.96690.37782.72961.028847\n续表61550.25215.31108610133.23980.67722.76390.59511560.2410.71108788-20.65850.65763.3957-1.39461570.1215.3110871003.84250.48924.40640.94871580.2283.7110888917.33610.55182.45420.69621590.2215.3110889916.72080.53222.29530.49421600.1259.81108990-2.42250.30841.8752-0.48721610.1215.311089983.4960.44513.69890.79641620.15228.811090918.99020.50872.95260.67561630.15215.3110909712.80420.72465.68381.22371640.15282.4110919212.54250.70985.47051.54491650.1215.311091966.16930.785510.592.281660.1237.211092936.31430.80411.05562.62241670.1215.311092956.01920.766410.1182.17841680.1215.311093940.9480.12070.32990.0711690.1237.21109495-2.6220.33382.1712-0.5151700.1282.41109596-4.16280.535.1107-1.44321710.1228.21109697-5.15350.65627.5892-1.73191720.1259.811097980.78070.09940.23030.05981730.1283.71109899-3.40330.43333.5194-0.99841740.1410.7110991003.88740.4954.50241.84911750.1376.9110100101-3.48010.44313.6678-1.38241760.2380.611010110218.75970.59712.84041.08111770.1298.11101021036.04750.7710.2063.04241780.1267.1110103104-2.07320.2641.4054-0.37541790.12781101041054.6220.58856.20371.724647\n2.3.5水泵的选择根据流量Q=1362.76L/s，故选择5台单级双吸式20SH-13A泵，4用1备，其工作参数见表2.8。表2.8水泵工作参数型号流量m³/h扬程m轴功率kw必须汽蚀余量m效率%20SH-13A14403418658547\n第三章排水管网设计说明与计算3.1排水系统的体制及其选择排水系统的体制，一般分为合流制和分流制两种类型：（1）合流制排水系统：将生活污水、工业废水、雨水混合在同一个管渠内排除的系统。现在常采用的是截流式合流制排水系统。这种系统是在临河岸边建造一条截流干管，同时在合流干管与截留干管相交前或相交处设置溢流井，并在截留干管下游设置污水厂。（2）分流制排水系统：是将生活污水、工业废水和雨水分别在两个或两个以上各自独立的管渠内排除的系统。排除生活污水、城市污水或工业废水的系统称为污水排水系统；排除雨水的系统称为雨水排水系统。在本设计中采用的是分流制排水系统。3.2排水系统的布置形式城市、居住区或工业企业的排水系统在平面上的布置，随着地形、竖向规划、污水厂的位置、土壤条件、河流情况，以及污水的种类和污染程度等因素而定。（1）正交式：地势向水体适当倾斜的地区，各排水流域的干管可以最短距离沿与水体垂直相交的方向布置，即为正交布置，但对水体污染较大。（2）截留式：在正交式的基础上，沿河岸再敷设主干管，并将个干管的污水截留送至污水厂，即为截留式布置。这种布置对减轻水体污染，改善和保护环境有重大作用。此外，还有平行式、分区式、分散式、环绕式布置，在此就不介绍了，在本设计中所采用的是截留式布置。3.3污水管网的布置污水管道平面布置，一般按确定主干管、干管、支管的顺序进行。在城市排水总体规划中，只决定污水主干管、干管的走向与平面布置，在详细规划中，还要决定污水支管的走向及位置。47\n3.4污水管道系统的设计污水管道系统的管线布置包括：确定排水区界，划分排水区域；选择污水厂出水口位置；拟定污水干管和主干管的路线；确定需要提升的排水区域和设置泵站的位置等。在施工图设计时，需要确定街道支管的路线及管道在街道上的位置等。3.4.1污水管道的定线应尽可能在管线较短，埋深较小的情况下，让最大区域的污水能自流排出，管道布置尽量顺直。定线时通常考虑的因素有地形和竖向规划、排水体制和其他管线的情况、污水厂和出水口的位置、水文地质条件、道路宽度、地下管线及构筑物的位置、工业企业和产生大量污水的建筑物的分布情况以及发展远景和修建顺序等。3.4.2控制点的确定在排水区域内，对管道系统的埋深起控制作用的地点称为控制点。各条管道的起点一般是这条管道的控制点，这些控制点中离出水口最远的一点，通常是整个系统的控制点。另外，具有相当深度的工厂污水排出口或默写低洼地区的管道起点，也可能是整个管道系统的控制点，这些控制点的管道埋深，影响整个管道系统的埋深。3.4.3污水管道系统设计参数（1）设计充满度污水管道应按照非满流设计，其最大设计充满度见表3.1。表3.1最大设计充满度管径D或渠道高度H/mm最大设计充满度管径D或渠道高度H/mm最大设计充满度200～3000.55500～9000.70350～4000.65≥10000.75（2）设计流速47\n污水的流速较小时，污水中所含杂质可能下沉，产生淤积；当污水中流速较大时，可能产生冲刷现象，甚至损坏管道，为了防止管道中产生淤积或冲刷，设计流速不宜过小或过大，应限制在最小和最大设计流速之间。根据规范，污水管道在设计充满度下最小设计流速为0.6m/s，金属管道的最大设计流速为10m/s，非金属管道的最大设计流速为5m/s。（3）最小管径污水管道管径过小，极易堵塞，造成养护费用增加，因此，长采用较大管径，较小管道坡度，减小埋深。（4）最小设计坡度在污水管道设计时，管道敷设坡度与设计地区的地面坡度基本保持一致，管道坡度造成的流速应等于或大于最小设计流速，以防止管道内沉淀。规范规定管径200mm的最小设计坡度为0.004；管径300mm的最小设计坡度为0.003。（1）污水管道的埋设深度污水管道的埋设深度是指管道的内壁地距地面的垂直距离，为了保证污水管道不受外界压力和冰冻的影响和破坏，管道的覆土厚度不应小于一定的最小限值，这一限值称为最小覆土厚度，应满足下述三个因素的要求：①防止管道中的污水冰冻和因土壤冰冻膨胀而损坏管道；②防止管道被车辆造成的动荷载压坏；③满足支管在衔接上的要求。（2）污水管道的衔接管道衔接有管顶平接和水面平接两种，水面平接主要用于地面比较平坦地区，在本设计中采用的是管顶平接。3.4.4污水管道上的主要构筑物为了排除污水，还需在管道上设置某些附属构筑物，包括检查井，跌水井，倒虹管。（1）检查井：便于对管渠系统做定期检查和清通，通常设在管渠交汇、转弯、管渠尺寸或坡度改变、跌水等处以及相隔一定距离的直线管段上，检查井在直线管渠段上的最大间距见表3.2。表3.2检查井的最大间距管径或暗渠净高（mm）最大间距（m）47\n污水管道雨水（合流）管道200～4003040500～7005060（2）跌水井：当检查井内衔接的上、下游管渠的管底标高跌落差大于1m，为消减水流速度，防止冲刷，在检查井内应有消能措施，这种检查井称为跌水井，有两种形式：竖管式和溢流堰式。（3）倒虹管：排水管渠遇到河流、山涧、洼地、铁路或地下构筑物等障碍时，不能按原有的坡度埋设，而是按下凹的折线方式从障碍物下通过，这种管道为倒虹管，在本设计中，因为要穿越铁路，所以也设置了倒虹管。3.5污水管道系统水力计算3.5.1污水流量的计算已知设计城镇总人口20万，街区面积305.7ha，居住区人口密度为654.2cap/ha。（1）综合生活污水定额按综合生活用水定额的70%计算，即：则污水平均日流量：查表可知，污水量总变化系数（2）居住区生活污水设计流量计算（3）比流量计算3.5.2集中流量计算按集中给水的70%计算，即：化工区16.8L/s、火车站10.5L/s、皮毛厂12.6L/s、针织厂8.4L/s、棉纺厂8.4L/s、食品厂8.47L/s。47\n3.5.3污水干管设计流量计算根据设计管段的定义和划分的方法，将各干管和主干管中有本段流量进入的点、集中流量及旁侧支管进入的点，作为设计管段的起止点的检查井并边上号码。计算附表1。3.5.4污水管道水力计算污水主干管、干管水力计算见附表2和附表3。3.6雨水管渠的设计与计算3.6.1雨水管渠系统的设计步骤雨水管渠系统设计的主要任务就是及时的汇集城镇或工业区汇水面积内的暴雨径流流量，并使雨水通畅的从城镇和工业区内排出，使生产和人们的生活不受到影响。（1）确定暴雨强度公式：式中P—暴雨强度的重现期，取1年；t—集水时间，，t1为地面集水时间，取5～15min，本设计取10min；t2为管渠内雨水流行时间，（min）则（2）确定径流系数由于此设计无详细资料，故采用区域综合径流系数。成都取0.6.（3）确定单位面积径流量q0（4）确定雨水设计流量Q47\n计算见附表4雨水干管水力计算表。3.6.2雨水管道构筑物（1）雨水口：雨水口的设置位置应能保证迅速有效地收集地面雨水。一般应在交叉路口、路测边沟的一定距离处以及没有道路边石的低洼地方设置，以防止雨水漫过道路或造成道路及低洼地区积水而妨碍交通。雨水口的形式和数量，通常应按汇水面积所产生的径流量和雨水口的泄水能力而确定。（2）溢流井：超过排水能力后直接排入水体。（3）出水口：为使雨水与水体水混合较好，管渠出水口一般采用淹没式，也可采用非淹没式，其底标高最好在水体最高水位之上，以免水体水倒灌。结论通过这次设计，我又一次巩固了书本上所学的知识，加强了理论与实践的结合，提高了我的动手能力，制图能力，思考能力。另外通过查阅资料也让我学到了课本以外的知识，增加了我的理论水平。同时通过不断的发现错误，分析错误，改正错误我也得到了很大的提高，也让我认识到了自己的不足，我会在以后的工作学习中不断地提高自己，争取更好地为社会服务。47\n总结与体会毕业设计是对我们大学四年所学知识的一次大规模的练兵，它让我对专业知识有了一个更加系统明了的认识，通过这次对某县城镇给排水管网的设计，让我认识到了作为一名即将毕业的给排水管网设计人员身上所担负的责任，为了这一责任，我还有很多要学习充实自己的地方。我会继续向前努力。谢辞这次毕业设计能够顺利的完成，首先我要感谢杨**老师的帮助，从始至终他都给予了我细致的指导，杨老师严谨的教学态度和广博的专业知识使我受益匪浅，另外我还要感谢李老师，王老师，宁老师在专业课上对我的教导，同时我也要感谢对我提供了帮助的同学，最后我要感谢养育我、培养我的父母和提供了良好学习环境的学校。再次向他们表示诚挚的谢意。参考文献[1]严煦世.给水工程.北京：中国建筑工业出版社，1999[2]汪翙.给水排水管网工程.北京：化学工业出版社，2005[3]张启海.城市给水工程.北京：中国水利水电出版社，2002[4]颜锦文.水泵及水泵站.北京：机械工业出版社，2006[5]孙慧修.排水工程.北京：中国建筑工业出版社，1999[6]中国市政工程西北设计研究院.给水排水设计手册（第11册）—常用设备.北京：中国建筑工业出版社，2002[7]于尔捷.给水排水工程快速设计手册(第2册)—排水工程.北京：中国建筑工业出版社，1996年[8]北京市市政设计研究总院.给水排水设计手册(第5册)—城镇排水，北京：47\n中国建筑工业出版社，2003[9]中华人民共和国水利部.泵站设计规范（GB/T50265-97）.北京：中华人民共和国建设部，1997[10]上海市政工程设计研究院.给水排水设计手册(第3册)一城镇给水，北京：中国建筑工业出版社，2003年47