搜索
DrainagesystemdesignreportDrainagesystemdesignreport1.IntroductionDrainageistypicallydefinedasthenaturalorartificialremovalofsurfacewaterfromanarea.AsstatedinWikipedia(2007),adrainagesystemisthepatternformedbythestreams,rivers,andlakesinaparticulardrainagebasin.Forcivilengineers,whoareresponsiblefordrainageinconstructionprojects,oftensetoutfromtheplansalltheroads,streetgutters,culvertsandsewersinvolvedinconstructionoperations.Therearetwomainlydrainagesystemswhicharefoulwaterdrainageandstormwaterdrainage.Foulwaterdrainagetransportsdomesticandindustrialwastewaterwithnoconcernofseverecontamination.However,itisrequiredtoconsiderstormwaterdrainageonlyinthisproject.Theothertypeisstormwaterdrainage,whichcanpreventfloodingmainlycausedbyrain,snow,sleetorotherkindsofprecipitation.AccordingtowiseGEEK(n.d.),stormwaterdrainageistheprocessofdrainingsurpluswaterfromstreets,sidewalks,roofs,buildings,andotherareas.Thesystemsusedtodrainstormwaterareoftenreferredtoasstormdrains,buttheyarealsocalledstormsewersanddrainagewells.Withoutproperdrainage,excesswatermaycollectandpresentdangerstobothpeopleandphysicalproperty.Therefore,aproperdrainagedesignisnecessaryandimportant.ThiscourseworkaimstodesignasurfacewaterdrainagesystemofpipestoremoveallrainwaterrunofffromamultiplotsitedevelopmentintheMerseysideareaanditsassociatedaccessroad/footwaysystem,andtodirectrainwatertooutfallintothenearbybrook.Wedeterminedtwoschemeswhicharebasedonahumanpointofviewandsavingpointofview.Thisreportwillmainlyintroducetheproject,wholeprocesswithdetailedexplanationandsomediscussionabouttheresultinthefollowing.2.Theproject2.1SitedescriptionItisobservedfromthemapthattherearemainlytworoads,onebrookandsomebuildingsinsite.ThefirstroadstartsfromYetownandgoesallthewayeasttoXeville.TheotheronegoesfromBarnoldswicktoDolchesteralongwiththebrook.Asthemarkindicates,waterlevelofthebrookis59.8mAOD.ThegroundleveloftheroadfromYetownisabout60.0mto62.6m.Thegroundlevelofthelandontherightsideofthebrookisintherangeofabout62.3mto65.8m.Besides,therearePrice’sFarm,ManeFarmand4buildingsneartheroadsandacarparkand5-storeyofficebuildinginthelowerrightcornerofthemap.2.2RainfallcharacteristicsThroughsearchingthepositionofMerseyside,itcanbefoundthelocationofthesiteinthemiddleofwestpartofUKwhichissignedintheappendix.Thesiteislocatedthehorizontalline4andverticalline3.5ofnationalgridforthefigure.Therefore,fromDrainagesystemdesignreportappendixA.1thevalueofM5-60minis20mm.AndfromappendixA.2,theratioofM5-60min/M5-2dayrainfalldepth-ris0.45.Theratiorindicatesthetypeofrainfall,wherelowvaluesofr(20)representrainthatmostlyfallsasdrizzle,whereasvaluesr(0.4)indicatetheprevalenceofmuchhigherintensitystorms.Therefore,fromappendixA.2wecandeducethattherainfallintensityofMerseysideishigher.ThegeneralrainfallintensitycharacteristicofUKissoutheastintensitystormshigherthannorthwest.3.Procedure3.1AnalysisofthemapanddeterminethedrainageschemesBeforewedesignthedrainagesystem,weneedtoanalyzethetopographyandthepositionofbuildings,brook,gatesandsoon.Fromthismap,wecanseethatthebuildingsareinthesoutheastandthebrookisontheleftsideofbuilding.TherearethreegatesA,BandCnearbythebuilding(seefigure3.1).Therefore,wedeterminedtousetwoofthemastheoutfall.Thenwestartedtodecidetheroadsandpavingareas.Therequirementaskedusthatatleast3sidesofeachdevelopmentplotmustbeservedbyroadaccessandthesewersmustrunalongandbeneaththefulllengthofallaccessroads.Therefore,wewanttofindtheshortestroute,whichcannotonlysavethetimefromhighwaytobuildingbutalsosavecostofthesewers.Wealsothoughtthattheroadsneednottocovertheoveralllengthofthreesidesofthebuilding,justhaveanaccesstothebuildingwhichispaving.Anotheroneisthesewerscannotsetmuchclosertothebuildingtoavoidsettlementofbuildingwhenexcavatingthesoil.Accordingtoabovedemandsweselectedtworoadschemesandwealsodeterminedthecatchmentareaswhichincludeallofbuildingsandroads.Figure3.1SitemapDrainagesystemdesignreportFortheplanone,wechosegate-Bastheoutfall.Inthisschemewestartfromahumanpointofview,peoplecanreachthecarparkfirstlyandthengototheofficebuilding.Wechoseside1,2and3forthecarparkservedbyroadaccessbecausetheyaremuchclosertotheoutfall.Fortheofficebuilding,weselectedside1,2,and4whichareclosertothecarparkandpeoplecanenterintothebuildingfromparkconveniently.Catchmentareaofplanone:A=22.1×29×500×500÷1000=16022.5×10−6𝑘𝑚2Fortheplantwo,wedeterminedtousegate-Aastheoutfallbecauseoftheshorterdistance.Savingisthebasicpointofviewinthisscheme.Wechoseside1,2and3ofcarparkandside1,2,and3ofofficebuilding.Wewantedtousetheleastresourcesandlabortoachievethisprojectandsatisfyrequirementaswell.Catchmentareaofplantwo:A=28.55×20.7×500×500÷1000=14774.625×10−6𝑘𝑚23.2SketchthedrainagesystemanddeterminethegroundlevelofmanholesThescaleis1:500inthemapsothataccordingtotherequirement(8mwidth)allthewidthoftheroadis1.6cm.Andwedeterminedthedistancebetweenroadwayandbuildingisnolessthan2mtoavoidsettlementofbuildingandthewidthisthesameastheroadsothatallkindsofvehiclescanaccesstothebuilding.Thefollowingtwofigureswillshowtheschemesforplanonea