《钢结构安装》课件-1.3.2 支座节点

1.3.2支座节点

Supportnode第一：压力支座节点First:pressuresupportnode第二：拉力支座节点Second:tensilesupportnode钢结构中的支座节点一般采用铰节点，尽量采用传力可靠、连接简单的构造形式。Thesupportnodesinthesteelstructuregenerallyadopthingenodes,andtrytoadoptthestructuralformofreliableforcetransmissionandsimpleconnection.

一、压力支座节点

First:pressuresupportnode

常用的压力支座节点有以下几种构造形式：Commonlyusedpressuresupportnodeshavethefollowingconstructionforms1.平板支座节点：通过十字节点板和底板将支座反力传给下部结构。Platesupportnodes:Thesupportreactionforceistransmittedtothesubstructurethroughthecrossgussetplateandthebaseplate.优点：节点构造简单，加工方便，用钢量省。Advantages:simplenodestructure,convenientprocessing,andeconomicalamountofsteel.缺点：节点处不能转动，受力后会产生一定的弯矩，与计算假定相差较大，可用于较小跨度的网架中。Disadvantages:Thenodecannotrotate,andacertainbendingmomentwilloccuraftertheforce,whichisdifferentfromthecalculationassumptionandcanbeusedinthegridframewithasmallerspan.焊接空心球压力支座Weldhollowballpressuresupports焊接钢板压力支座Weldedsteelplatepressuresupport柱头上的预埋螺栓仅起定位作用，安装就位后应将底板与下部支承面板焊牢Theembeddedboltsonthecolumnheadonlyplayapositioningrole,andthebottomplateshouldbeweldedfirmlytothelowersupportpanelafterinstallationinplace2.单面弧形压力支座节点Single-sidedarcpressuresupportnode在平板压力支座的基础上，在节点底板和下部支承面板间设一弧形垫块而成。适用于中、小跨度网架。Onthebasisoftheplatepressuresupport,anarc-shapedpadisprovidedbetweenthenodebottomplateandthelowersupportpanel.Suitableformediumandsmallspangrids.这种支座节点在压力的作用下，支座底板沿垫块弧面可以转动，下部支承面板上的压力比较均匀，但摩擦力仍然较大。为了保证支座节点的转动，柱头上预埋螺栓应设在弧形垫块中心线上，支座底板上的螺栓孔可做成椭圆形，使支座节点有微量的平移。Undertheactionofpressure,thesupportbottomplatecanrotatealongthearcsurfaceofthepad,andthepressureonthelowersupportpanelisrelativelyuniform,butthefrictionisstilllarge.Inordertoensuretherotationofthesupportnode,theembeddedboltonthecolumnheadshouldbesetonthecenterlineofthearcwasher,andtheboltholeonthesupportbottomplatecanbemadeintoanovalshape,sothatthesupportnodehasasmallamountoftranslation.3.双面弧形压力支座节点（摇摆支座节点）Double-sidedarcpressuresupportnode(swingsupportnode)

当网架的跨度较大、温度应力影响显著、周边约束较强时，需要选择一种既能自由伸缩又能自由转动的支座节点形式。Whenthespanofthegridframeislarge,theinfluenceoftemperaturestressissignificant,andtheperipheralconstraintisstrong,itisnecessarytochooseasupportnodeformthatcanbothfreelyexpandandrotate.缺点：节点构造复杂，施工麻烦、造价较高。对抗震不利，在我国应用较少。Disadvantages:Thenodestructureiscomplex,theconstructionistroublesome,andthecostishigh.ItisnotgoodforearthquakeresistanceandislessusedinChina.3.双面弧形压力支座节点（摇摆支座节点）Double-sidedarcpressuresupportnode(swingsupportnode)构造：在支座底板和柱顶面板间设一块上下均为弧形的铸钢板，然后用螺栓将支座上、下支承托板和双面弧形铸钢板三者练成整体。支座上、下支承板开有椭圆孔，使支座节点在荷载和温度变化的作用下既可以转动又可以作一定的侧移。Structure:Acaststeelplatewitharc-shapedupperandlowerlevelsissetbetweenthesupportbottomplateandthecolumntoppanel,andthentheupperandlowersupportplatesandthedouble-sidedarccaststeelplatearetrainedintoawholebybolts.Theupperandlowerbearingplatesofthesupportareopenedwithellipticalholes,sothatthesupportnodescanrotateandmakecertainlateralshiftsundertheactionofloadandtemperaturechanges.4.球铰压力支座节点Ballhingepressuresupportnode

对于多支点大跨度网架，为了能使支座节点适应各个方向的自由转动，需使支座与柱顶铰接而不产生弯矩，常做成球铰压力支座。Forthemulti-fulcrumlong-spangrid,inordertoadaptthesupportnodetothefreerotationinalldirections,itisnecessarytohingethesupportwiththetopofthecolumnwithoutgeneratingbendingmoment,anditisoftenmadeintoaballhingepressuresupport.构造：由置于柱顶面板上的一个半圆球与一个连于节点底板上凹形半球的铸钢块相互嵌合，用4个螺栓固定，并在螺帽下设置弹簧垫圈而组成。利于抗震。Structure:Itconsistsofasemi-circularballplacedonthetoppanelofthecolumnandacaststeelblockconnectedtoaconcavehemisphereonthebaseplateofthenode,fixedwith4bolts,andaspringwasherisprovidedunderthenut.Goodforearthquakeresistance.5.板式橡胶支座节点Platerubbersupportnode在柱顶面板与节点板间设置一块橡胶垫板组成，适用于大、中跨度网架。目前在国内应用较广。Arubberpadissetbetweenthecolumntoppanelandthegussetplate,whichissuitableforlargeandmediumspangridframes.Atpresent,itiswidelyusedinChina优点：构造简单、安装方便、节省钢材、造价较低。Advantages:simplestructure,easyinstallation,savingsteel,lowcost.构造：橡胶垫板由多层橡胶片和薄钢板粘合、压制而成，节点底板和下部支承用螺栓连接。橡胶垫板具有良好的弹性，也可产生较大的剪切变形，因而既可以满足网架支座节点的转动要求，又可以在外界水平力的作用下产生一定的侧向位移。Structure:Therubbergasketisbondedandpressedbymulti-layerrubbersheetandthinsteelplate,andthebottomplateandthelowersupportofthenodeareconnectedbybolts.Therubbergaskethasgoodelasticityandcanalsoproducelargesheardeformation,soitcannotonlymeettherotationrequirementsofthegridsupportnode,butalsoproduceacertainlateraldisplacementundertheactionofexternalhorizontalforce.二、拉力支座节点Second:tensilesupportnode

网架的支座节点一般均传递压力，但周边简支的正交斜放类网架在角隅处往往会产生拉力，因此在设计时应根据支承点的受力特点设计拉力支座节点。

Thesupportnodesofthegridframegenerallytransmitpressure,buttheorthogonalobliquegridframeofthesurroundingsimplesupportoftengeneratestensileforceatthecorner,sothetensionsupportnodeshouldbedesignedaccordingtotheforcecharacteristicsofthesupportpointwhendesigning.1.平板拉力支座节点：对于小跨度网架，支座处拉力一般较小，可用平板拉力支座节点。Flatplatetensionsupportnode:Forsmallspangridframe,thetensionatthesupportisgenerallysmall,andtheflatpullsupportnodecanbeused.该节点利用锚固螺栓承受拉力。拉