Constructionlayout主講人：LiSimengThislessoncontains2parts：TheyareTheknowledgeoftheConstructionlayout,andthesentenceanalysis.01ConstructionLayoutCONTENTS目錄PARTONEConstructionLayout01ConstructionLayoutConstructioncontrolThefirston-sitejobfortheconstructionsurveyoristorelocatethehorizontalandverticalcontrolusedinthepreliminarysurvey.Generallyspeaking,thehorizontalandverticalcontrolusedinthepreliminarysurveymaynotbeusedagaininconstructionsurveying,Dependingonthesizeandcomplexityoftheprojectaswellastheprecisionrequirements,itmaybenecessarytoreestablishthehorizontalandverticalcontrolintheareasofproposedconstruction.Forexample,theconstructionsurveyorwillestablishoneormorebenchmarksinthegeneralvicinityoftheproject.Thesebenchmarksareplacedawayfromtheimmediatevicinityofthebuildingssotheywillnotbedestroyedbytheconstructionoperations,andareusedtoprovideverticalcontrolfortheproject.Oncetheseareset,thesurveyorwillthenestablishagoodmanylesspermanentbutmoreaccessiblebenchmarksquiteclosetotheproject.Thelocationoftheselesspermanentpointsshouldbecarefullyselectedsothatturningpointswillideallynotbeneededwhenelevationshavetobesetattheproject."Suchcarefulselectionofthepointsmayresultincriticaltimesavingwhichissoimportantonconstructionproject.ConstructionLayoutLayoutItisobviouslycriticalforaconstructionjobthatthevariouspartsofthestructurebeplacedatthedesiredelevation.Toaccomplishthisgoaltheconstructionsurveyorwillestablishthereferencelinesorbaselinesbeforetheactuallayoutmeasurementsbegins.Forlargeconstructionprojects,theusualprocedureistosetamainbaselinedownthecenterlineofthestructure,suchasthecenterlineofthebridge.Themonumentsaresetalongthecenterlineateachendbeyondtheareaoftheconstructionwork,Themonumentsalongtheendsofthelinemaybeoccupiedbythesurveyorandwillenablehimtocheckandresetpointswithintheconstructionareas.Thestakesandpointssetduringtheprocessofconstructionsurveyingarenotusuallysetattheactualconstructionpoint,butusuallyonsomesortofoffset.Thisisdonesothatthesurveystakeisnotdisturbedbyexcavationorotheractivitiesthatwilltakeplaceattheactualpointofconstruction.Thestakesaremarkedwithan“offset”anda“grade"whichprovidestheconstructioncrewwiththespecialrelationshipoftheconstructionstaketotheactualpointofconstruction.The“offset”isthedistancefromthesurveystaketothehorizontalpositionoftheactualpointofconstruction,andwouldtypicallybethreefeetforcurbandguttertotenfeetforundergroundpipes.ConstructionLayoutTechniquesofLayoutInconstructionlayoutmeasurement,thedatanecessarytoestablishthedirectionanddistancefromacontrolpointtolocateaconstructionpointcanbeenteredintotheinstrumentviathekeyboardordirectlyfromanofficecomputer.Thenthesurveyorguidesthepersonholdingtheprismalongthelineofcomputeddirectionuntilthedistancetothepointtobelocatedagreeswiththecomputeddistance.Varioustechniquesmaybeappliedtoaccomplishthisgoal.Averypopulartechniquecalledfreestationpermitsthesurveyortosetupthetotalstationatanyconvenientpositionandthentodeterminethecoordinatesandelevationofthatinstrumentpositiobysightingpreviouslycoordinatedreferencestations."Aftertheinstrumenthasbeensetupoverthisinstrumentposition(acontrolpoint)andproperlyoriented,anglesorazimuthsfromthecontrolpointanddistancestoeachlayoutpointmaybeindicated.Nowmanytotalstationshavesuchfunctionsthatthecoordinatesandelevationsofthelayoutpointsmaybeuploadedintothetotalstation,theinstrument'sdisplayshowstheleft/right,forward/back,andup/downmovementsneededtoplacetheprismineachofthedesiredpositions.ConstructionLayoutAs-builtsurveysWhentheconstructionsurveyinghasbeencompleted,afinalsurveyisperformed,Thefinalsurveyincludescrosssectionsandlocationsthatareusedforfinalpaymentstothecontractorandforthecompletionofanas-builtdrawing.Thesearetheas-builtsurveysandtheyareusedtocheckthecontractor'sworkandshowlocationsofstructuresandtheircomponents(waterline,sewer,etc.),whichwillbeneededforfuturemaintenance,changes,andnewconstruction.ConstructionLayoutTheSentenceAnalysisTheengineers,architectsorbuildingcontractorsneedtoknowinformationaboutoverallsitegradeandelevationstodetermineplacementofsitestructures,orestimatethevolumeofdirttobemoved,andthentosettherequiredhorizontalandverticalpositionsforthestructures.工程師、建筑師或建筑承包商需要了解整個工地的坡度和高程來進行施工現場建筑物的布置,或估算需要開挖的土方量,然后放樣建筑物的水平位置和高程。ConstructionLayoutTheSentenceAnalysisThesebenchmarksareplacedawayfromtheimmediatevicinityofthebuildingssotheywillnotbedestroyedbytheconstructionoperations,andareusedtoprovideverticalcontrolfortheproject.Oncetheseareset,thesurveyorwillthenestablishagoodmanylesspermanentbutmoreaccessiblebenchmarksquiteclosetotheproject.Thelocationoftheselesspermanentpointsshouldbecarefullyselectedsothatturningpointswillideallynotbeneededwhenelevationshavetobesetattheproject."ConstructionLayoutTheSentenceAnalysis本句話so為并列連詞，連接兩個獨立的句子，用來表示因果關系，第一句的主要框架為Thesebenchmarksare......，andareusedto...。第三個句子，sothat引導了目的狀語從句。這些基準點應埋設在遠離建筑物的地方,以免在施工過程中被損毀,并為工程提供高程控制。一旦這些基準建立之后,測量員就可以在緊鄰工程施工處外建立大量便于使用的非永久性基準點。這些非永久性基準點的位置需要細心地選擇,以便在理想條件下工程施工放樣中不需要設置轉點就可以放樣高程。ConstructionLayoutTheSentenceAnalysisThestakesaremarkedwithan“offset”anda“grade"whichprovidestheconstructioncrewwiththespecialrelationshipoftheconstructionstaketotheactualpointofconstruction.本句中which引導的定語從句修飾限定an“offs