《鋼結(jié)構(gòu)安裝》課件-3.8.1 鋼網(wǎng)架結(jié)構(gòu)的準備工作

3.8.1鋼網(wǎng)架拼裝的準備工作

3.8.1Preparationforsteelgridassembly第一：鋼網(wǎng)架的結(jié)構(gòu)形式及選擇First:thestructuralformandselectionofsteelgridframe第二：鋼網(wǎng)架的技術(shù)尺寸及節(jié)點構(gòu)造Second:thetechnicalsizeandnodestructureofthesteelgridframe第三：鋼網(wǎng)架拼裝的準備工作Third:thepreparationofsteelgridassembly

一、鋼網(wǎng)架的結(jié)構(gòu)形式及選擇

First:thestructuralformandselectionofsteelgridframe

平板網(wǎng)架是一種新型的結(jié)構(gòu)形式，不僅具有跨度大、覆蓋面廣、結(jié)構(gòu)輕、省料經(jīng)濟等特點，還具有良好的穩(wěn)定性和安全性，多用于體育館、俱樂部、展覽館、影劇院、車站候車大廳等公共建筑，也可用于大型文化娛樂中心等。Flatgridframeisanewtypeofstructuralform,notonlyhasthecharacteristicsoflargespan,widecoverage,lightstructure,materialsavingeconomy,etc.,butalsohasgoodstabilityandsafety,mostlyusedingymnasiums,clubs,exhibitionhalls,theaters,stationwaitinghallsandotherpublicbuildings,canalsobeusedinlargeculturalandentertainmentcenters.網(wǎng)架結(jié)構(gòu)的類型Thetypeofgridstructure01由平面桁架組成的兩向正交正放網(wǎng)架、兩向反交斜放網(wǎng)架、兩向斜交斜放網(wǎng)架和單向折線形網(wǎng)架Two-wayorthogonalorthogonalgridframe,two-wayreversecross-the-slopegridframe,two-waydiagonaldiagonalgridframeandunidirectionalpolylinegridframecomposedofflattrusses03由三角錐體組成的三角錐網(wǎng)架、抽空三角錐網(wǎng)架和蜂窩形三角形網(wǎng)架Triangularconegrid,evacuationtriangularconegridandhoneycombtriangulargridconsistingoftriangularcones02由四角錐體組成的正放四角錐網(wǎng)架、正放抽空四角錐網(wǎng)架、棋盤形四角錐網(wǎng)架、斜放四角錐網(wǎng)架、星形四角錐網(wǎng)架Positivefour-cornerconegridframe,positivedischargeevacuationfour-cornerconegrid,checkerboard-shapedfour-cornerconegrid,obliquefour-cornerconegrid,star-shapedfour-cornerconegrid

兩向正交正放網(wǎng)架Two-wayorthogonalpositiveplacementgrid兩向正交斜放網(wǎng)架Two-wayorthogonaldiagonalgridframe兩向正交正放網(wǎng)架----適用于在矩形建筑平面中，網(wǎng)架的弦桿垂直于及平行于邊界Two-wayorthogonalgrid----suitableforrectangularbuildingplaneswherethechordofthegridisperpendiculartoandparalleltotheboundary兩向正交斜放網(wǎng)架----適用于兩個方向網(wǎng)格尺寸不同的情況Two-wayorthogonaldiagonalgridframe----suitablefordifferentgridsizesintwodirections

三向網(wǎng)架：三個方向的平面桁架相互交角60°。比兩向網(wǎng)架剛度大，適合大跨度，適用于正三角形，正六三角形平面。Three-waygrid:Theplanetrussesinthreedirectionsintersecteachotheratanangleof60°.Itisstifferthanthetwo-waygridframe,suitableforlargespans,suitableforregulartriangle,regularsixtriangleplane.三向網(wǎng)架Three-waygrid

正放四角錐網(wǎng)架：以倒四角錐體為組成單元，上、下弦桿均與相應(yīng)邊界平行。正放四角錐網(wǎng)架的上、下弦節(jié)點均分別連接八根桿件。

Positivefour-cornerconegrid:withtheinvertedfour-cornerconeasthecompositionunit,theupperandlowerchordsareparalleltothecorrespondingboundary.Theupperandlowerchordnodesoftheuprightfour-cornerconegridframeareconnectedtoeightmembersrespectively.斜放四角錐網(wǎng)架：上弦網(wǎng)格呈正交斜放，下弦網(wǎng)格為正交正放。網(wǎng)架上弦桿短，下弦桿長，受力合理。由錐底構(gòu)成的上弦桿與邊界成45°夾角，而連接各錐頂?shù)南孪覘U則與相應(yīng)邊界平行。斜放四角錐網(wǎng)架上弦桿長度比下弦桿長度小，在周邊支承的情況下，通常是上弦桿受壓，下弦桿受拉，因而桿件受力合理。此外，節(jié)點處匯交的桿件（上弦節(jié)點六根，下弦節(jié)點八根）相對較少，用鋼量較省。Diagonalfour-cornerconegrid:theupperchordgridisorthogonalandoblique,andthelowerchordgridisorthogonal.Theupperchordofthegridframeisshort,thelowerchordislong,andtheforceisreasonable.Theupperchordconsistingofthebottomoftheconeisatanangleof45°totheboundary,whilethelowerchordconnectingthetopofeachconeisparalleltothecorrespondingboundary.Thelengthoftheupperchordoftheobliquefour-cornerconegridframeissmallerthanthelengthofthelowerchord,andinthecaseofperipheralsupport,itisusuallytheupperchordthatispressedandthelowerchordispulled,sothememberisreasonablystressed.Inaddition,themembers(sixupperchordnodesandeightlowerchordnodes)intersectatthenodesarerelativelysmall,andtheamountofsteelusedisrelativelysmall.左圖：正放四角錐網(wǎng)架Left:Four-cornerconegridframeisplacedupright右圖：斜放四角錐網(wǎng)架Right:Diagonallyplacedfour-cornerconegrid正放四角錐網(wǎng)架Placethefour-cornerconegridframeupright三角錐網(wǎng)架Triangularconegrid星形四角錐網(wǎng)架Starquadrangularconegrid棋盤四角錐網(wǎng)架Checkerboardquadrangularconegridframe網(wǎng)架結(jié)構(gòu)的選擇Choiceofgridstructure

選擇網(wǎng)架結(jié)構(gòu)的形式時，應(yīng)根據(jù)建筑物的平面形狀和尺寸、支承情況、荷載大小、屋面構(gòu)造、建筑要求、制造和安裝方法，以及材料供應(yīng)情況等因素綜合考慮。Whenchoosingtheformofgridstructure,itshouldbeconsideredaccordingtofactorssuchastheplaneshapeandsizeofthebuilding,thesupportingsituation,thesizeoftheload,theroofstructure,thebuildingrequirements,themanufacturingandinstallationmethods,andthesupplyofmaterials.(1)當(dāng)平面接近正方形時，以斜放四角錐網(wǎng)架最經(jīng)濟，其次是正放四角錐網(wǎng)架和兩向正交網(wǎng)架(正放或斜放)。(1)Whentheplaneisclosetothesquare,itismosteconomicaltoputtheobliquefour-cornerconegrid,followedbytheorthogonalfour-cornerconegridframeandthetwo-wayorthogonalgridframe(orthogonaloroblique).(2)當(dāng)跨度及荷載均較大時，采用三向網(wǎng)架較經(jīng)濟合理，而且剛度也較大。(2)Whenthespanandloadarelarge,itismoreeconomicalandreasonabletouseathree-waygridframe,andthestiffnessisalsolarger.(3)當(dāng)平面為矩形時，則以兩向正交斜放網(wǎng)架和斜放四角錐網(wǎng)架最為經(jīng)濟合理。(3)Whentheplaneisrectangular,thetwo-wayorthogonaldiagonalgridframeandobliquefour-cornerconegridframearethemosteconomicalandreasonable.二、鋼網(wǎng)架的技術(shù)尺寸及節(jié)點構(gòu)造Second:thetechnicalsizeandnodestructureofthesteelgridframe鋼網(wǎng)架的高度Theheightofthesteelgridframe網(wǎng)架的高度與跨度之比Theratiooftheheightofthegridtothespan(1)在確定網(wǎng)架高度時，不僅要考慮上下弦桿內(nèi)力的大小，還需充分發(fā)揮腹桿的受力作用，一般應(yīng)使腹桿與弦桿的夾角為

。1)Whendeterminingtheheightofthegridframe,notonlythesizeoftheinternalforceoftheupperandlowerchordsshouldbeconsidered,butalsotheforceeffectofthewebrodshouldbefullyexerted,andtheanglebetweenthewebrodandthechordshouldgenerallybe.(2)根據(jù)國內(nèi)工程實踐的經(jīng)驗綜合分析，網(wǎng)架的高度與跨度之比應(yīng)符合下表的規(guī)定。(2)Accordingtothecomprehensiveanalysisoftheexperienceofdomesticengineeringpractice,theratiooftheheightofthegridframetothespanshouldcomplywiththeprovisionsofthefollowingtableShortedgespanofthegridGridheight(3)在不同的屋面體系中，對于周邊支承的各類網(wǎng)架，其網(wǎng)格數(shù)及跨高比可按下表選用。該表是按經(jīng)濟和剛度要求制定的，當(dāng)符合表中規(guī)定時，一般可不驗算網(wǎng)架的撓度。(3)Indifferentroofingsystems,forvarioustypesofgridframessupportedbytheperimeter,thenumberofgridsandspanheightratiocanbeselectedaccordingtothefollowingtable.Thetableisformulatedaccordingtoeconomicandstiffnessrequirements,andwhenthetableismet,thedeflectionofthegridframecangenerallynotbecalculated.(4)當(dāng)屋面荷載較大時，為滿足網(wǎng)架相對剛度的要求(控制撓度)，網(wǎng)架高度應(yīng)適當(dāng)提高一些；當(dāng)屋面采用輕型材料時，網(wǎng)架高度可適當(dāng)降低一些；當(dāng)網(wǎng)架上設(shè)有懸掛的起重機或有吊重時，應(yīng)滿足懸掛起重機軌道對撓度的要求，在這種情況下，網(wǎng)架的高度就應(yīng)適當(dāng)?shù)厝「咭恍?4)Whentheroofloadislarge,inordertomeettherequirementsoftherelativestiffnessofthegridframe(controldeflection),theheightofthegridshouldbeappropriatelyincreased;Whentheroofismadeoflightmaterial,theheightofthegridframecanbeappropriatelyreduced;Whenthereisasuspendedcraneorliftingweightonthegridframe,thedeflectionrequirementsofthesuspensioncranetrackshouldbemet,inthiscase,theheightofthegridframeshouldbeappropriatelyhigher.鋼網(wǎng)架的高度TheheightofthesteelgridframeGridformNumberofmeshesStraddleheightratio1.平板網(wǎng)架網(wǎng)格的大小與屋面板的種類及材料有關(guān)，因此，網(wǎng)格的尺寸應(yīng)符合下列規(guī)定：1.Thesizeoftheflatgridgridisrelatedtothetypeandmaterialoftheroofpanel,therefore,thesizeofthegridshouldcomplywiththefollowingregulations:(1)當(dāng)選用鋼筋混凝土屋面板時，板的尺寸不宜過大，一般不超過3m見方為宜，否則會帶來吊裝的困難。(1)Whenthereinforcedconcreteroofpanelisselected,thesizeoftheslabshouldnotbetoolarge,generallynotmorethan3msquare,otherwiseitwillbringdifficultiesinhoisting.(2)若采用輕型屋面板材，如壓型鋼板、太空網(wǎng)架板時，一般需加設(shè)檁條，此時檁距不宜小于1.5m，網(wǎng)格尺寸應(yīng)為檁距的倍數(shù)。(2)Iflightroofpanelmaterialsareused,suchasprofiledsteelplatesandspacegridplates,purlinsaregenerallyrequired,andthepurlindistanceshouldnotbelessthan1.5m,andthegridsizeshouldbeamultipleofthepurlindistance.鋼網(wǎng)格的尺寸Thedimensionsofthesteelgrid2.為減少或避免出現(xiàn)過多的構(gòu)造桿件，網(wǎng)格的尺寸應(yīng)盡可能大一些。網(wǎng)格尺寸a與網(wǎng)架短向跨度之間的關(guān)系如下:2.Inordertoreduceoravoidexcessiveconstructionmembers,thesizeofthegridshouldbeaslargeaspossible.Therelationshipbetweengridsizeaandgridshortspanisasfollows:(1)當(dāng)網(wǎng)架短向跨度

<30m時，網(wǎng)格尺寸a=(1/6～1/12)。Whentheshortspanofthegridframeis<30m,thegridsizea=(1/6~1/12).(2)當(dāng)網(wǎng)架短向跨度30m≤

≤60m時，a=(1/10～1/16)。(2)Whentheshortspanofthegridframeis30m≤≤60m,a=(1/10~1/16).(3)當(dāng)網(wǎng)架短向跨度

>60m時，a=(1/12～1/20)。(3)Whentheshortspanofthegridframeis>60m,a=(1/12~1/20).3.由于網(wǎng)格的大小與桿件材料有關(guān):當(dāng)網(wǎng)架桿件采用鋼管時，由于鋼管截面性能好，桿件可以長一些，即網(wǎng)格尺寸可以大一些;當(dāng)網(wǎng)架桿件采用角鋼時，桿件截面可能要由長細比控制，故桿件不宜太長，即網(wǎng)格尺寸不宜過大。3.Becausethesizeofthegridisrelatedtothemembermaterial:whenthegridmemberadoptsasteelpipe,themembercanbelongerduetothegoodcross-sectionalperformanceofthesteelpipe,thatis,thegridsizecanbelarger;Whenthegridmemberadoptsanglesteel,themembersectionmaybecontrolledbythelengthandslendernessratio,sothemembershouldnotbetoolong,thatis,thegridsizeshouldnotbetoolarge.鋼網(wǎng)格的尺寸Thedimensionsofthesteelgrid

三、鋼網(wǎng)架拼裝的準備工作

Third:thepreparationofsteelgridassembly1.技術(shù)準備1.Technicalpreparation

(3)所有焊工必須有相應(yīng)焊接形式的上崗證書。(3)Allweldersmusthavethecorrespondingweldingformofthecertificate.

(4)對焊接節(jié)點(空心球節(jié)點、鋼板節(jié)點等)的網(wǎng)架結(jié)構(gòu)應(yīng)選擇合理的焊接工藝及順序，以減少焊接應(yīng)力與變形。(4)Thegridstructureofweldednodes(hollowballnodes,steelplatenodes,etc.)shouldbeselectedwithareasonableweldingprocessandsequencetoreduceweldingstressanddeformation.

(5)對小拼、中拼、大拼等工序，在正式拼裝前宜先進行試拼，檢查無誤后，再正式拼裝。(5)Forsmallassembly,mediumfighting,largeassemblyandotherprocesses,itisadvisabletoconducttrialassemblybeforeformalassembly,andthenformallyassembleaftercheckingthatitiscorrect.

三、鋼網(wǎng)架拼裝的準備工作

Third:thepreparationofsteelgridassembly1.技術(shù)準備1.Technicalpreparation

(1)編制拼裝工程施工組織設(shè)計或施工方案，并嚴格按此執(zhí)行，以確保網(wǎng)架焊接與拼裝質(zhì)量。(1)Preparetheconstructionorganizationdesignorconstructionplanoftheassemblyproject,andstrictlyimplementittoensurethequalityofgridweldingandassembly.

(2)拼裝過程所用計量器具如鋼直尺、經(jīng)緯儀、水平儀等，必須經(jīng)計量檢驗合格，且在檢定有效期內(nèi)使用。(2)Themeasuringinstrumentsusedintheassemblyprocess,suchassteelrulers,theodolitemeters,levels,etc.,mustpassthemeasurementinspectionandbeusedwithinthevalidityperiodoftheverification.2.材料準備2.Materialpreparation(1)零部件(1)Parts網(wǎng)架結(jié)構(gòu)所用鋼材材質(zhì)以及桿件、連接件、焊接球、螺栓球等的制作質(zhì)量必須符合設(shè)計要求，且有出廠合格證等相關(guān)質(zhì)量保證資料，并按現(xiàn)行國家標(biāo)準《鋼結(jié)構(gòu)工程施工質(zhì)量驗收視范》(GB50205-2001)的規(guī)定進行力學(xué)性能試驗和化學(xué)分析，經(jīng)檢測符合規(guī)范標(biāo)準和設(shè)計要求后方可使用。Theproductionqualityofsteelmaterialsusedingridstructureandmembers,connectors,weldingballs,boltballs,etc.mustmeetthedesignrequirements,andhaverelevantqualityassurancematerialssuchasfactorycertificates,andcarryoutmechanicalpropertytestsandchemicalanalysisinaccordancewiththecurrentnationalstandard"SteelStructureEngineeringConstructionQualityAcceptanceSpecification"(GB50205-2001),andcanonlybeusedaftertestingtomeetthespecificationstandardsanddesignrequirements.

(2)高強度螺栓

(2)High-strengthbolts

1)高強度螺拴的鋼材必須符合設(shè)計規(guī)定及相應(yīng)的技術(shù)標(biāo)準。鋼網(wǎng)架結(jié)構(gòu)用高強度螺栓必須采用國家標(biāo)準《鋼結(jié)構(gòu)用高強度大六角頭螺栓》(GB/T1228-2006)規(guī)定的性能等級8.8S或10.9S,并應(yīng)按相應(yīng)等級要求來檢查。1)High-strengthscrewedsteelmustmeetthedesignregulationsandcorrespondingtechnicalstandards.Thehigh-strengthboltsforsteelgridstructuremustadopttheperformancelevel8.8Sor10.9Sspecifiedinthenationalstandard"High-strengthHexHeadBoltsforSteelStructures"(GB/T1228-2006),andshouldbeinspectedaccordingtothecorrespondinggraderequirements.2.材料準備2.Materialpreparation2)高強度螺栓不允許存在任何淬火裂紋，表面要進行發(fā)黑處理。2)High-strengthboltsarenotallowedtohaveanyquenchingcracks,andthesurfaceshouldbeblackened.3)高強度螺栓抗拉極限承載力應(yīng)符合設(shè)計規(guī)定。3)Thetensileultimatebearingcapacityofhigh-strengthboltsshouldmeetthedesignregulations.4)網(wǎng)架拼裝前，應(yīng)對每個高強度螺栓進行表面硬度試驗，嚴禁有裂紋和損傷。高強度螺栓的允許偏差和檢驗方法應(yīng)滿足相關(guān)規(guī)范的規(guī)定。4)Beforethegridframeisassembled,thesurfacehardnesstestshouldbecarriedoutoneachhigh-strengthbolt,andcracksanddamagearestrictlyprohibited.Theallowabledeviationandinspectionmethodofhigh-strengthboltsshouldmeettheprovisionsofrelevantspecifications.(3)其他材料(3)Othermaterials拼裝過程中所用的連接材料，如焊條電弧焊的焊條、氣體保護焊實心焊絲等應(yīng)符合現(xiàn)行產(chǎn)品標(biāo)準和設(shè)計要求。Theconnectionmaterialsusedintheassemblyprocess,suchaselectrodesarcwelding,gasshieldedweldingsolidweldingwires,etc.,shouldmeetthecurrentproductstandardsanddesignrequirements.3.網(wǎng)架拼裝前的準備工作3.Preparationbeforegridassembly

(1)網(wǎng)架結(jié)構(gòu)應(yīng)在專門的胎架上進行小拼，以保證小拼單元的精度和互換性。(1)Thegridstructureshouldbesmallfightingonaspecialtireframetoensuretheaccuracyandinterchangeabilityofthesmallassemblyunit.

(2)胎架在使用前必須進行檢驗，合格后再拼裝。(2)Thetireframemustbeinspectedbeforeuse,andthenassembledafteritisqualified.

(3)在整個拼裝過程中，要隨時對胎具的位置和尺寸進行復(fù)核，如有變動，經(jīng)調(diào)整后方可重新拼裝。(3)Duringtheentireassemblyprocess,thepositionandsizeofthetireshouldbereviewedatanytime,andifthereisanychange,itcanbereassembledafteradjustment.

(4)網(wǎng)架的中拼裝片或條塊的拼裝應(yīng)在平整的剛性平臺上進行。拼裝前，必須在空心球表面用套模畫出桿件定位線，做好定位記錄，在平臺上按1：1大樣搭設(shè)立體模，以此來控制網(wǎng)架的外形尺寸和標(biāo)高，拼裝時應(yīng)設(shè)調(diào)節(jié)支點，以此來調(diào)節(jié)鋼管與球的同心度。(4)Theassemblyofthemiddleassemblysheetorstripofthegridframeshouldbecarriedoutonaflatrigidplatform.Beforeassembly,thepositioninglineofthemembermustbedrawnwithasetofmoldsonthesurfaceofthehollowball,apositioningrecordmustbemade,andabodymoldmustbesetupontheplatformaccordingtoa1:1sampletocontroltheexternalsizeandelevationofthegridframe,andanadjustmentfulcrumshouldbesetwhenassemblingtoadjusttheconcentricityofthesteelpipeandtheball.

3.網(wǎng)架拼裝前的準備工作3.Preparationbeforegridassembly(5)焊接球節(jié)點網(wǎng)架結(jié)構(gòu)在拼裝前應(yīng)考慮焊接收縮，其收縮量可通