简介:本文介绍了茅岭江特大桥钢壁双围堰的施工工艺。该工艺立足国内现有的施工技术、施工方法、机械设备和工程材料,进行施工技术的综合研究,全面优化。从钢壁双围堰的设计考虑承台的施工,施工中充分利用潮位涨落进行钢围堰的下水浮运,通过调节壁内水位高低控制钢围堰的下沉,便于上部钢围堰的拼接。最大的优点是减少了船舶的使用。在双壁钢围堰定位过程中,利用栈桥平台和钢围堰四周的4根钢管桩作为油葫芦受力点进行钢围堰精确定位,避免了使用锚索,确保了航道内船只的畅通。并且在施工中未搭设水中拼装平台,节约了成本,减少了征地,加快施工进度、节约工程成本的成功施工经验。
简介:Mostoftheinvestigationsregardingfrictionstirwelding(FSW)ofaluminumalloyplateshavebeenlimitedtoabout5to6mmthickplates.InpriorworkconductedthevariousaspectsconcerningtheprocessparametersandtheFSWtoolgeometrywerestudiedutilizingfrictionstirweldingof12mmthickcommercialgradealuminumalloy.Twodifferentsimple-tomanufacturetoolgeometrieswereused.TheeffectofvaryingweldingparametersanddwelltimeofFSWtoolonmechanicalpropertiesandweldqualitywasexamined.Itwasobservedthatinordertoachieveadefectfreeweldingonsuchthickaluminumalloyplates,toolhavingtrapezoidalpingeometrywassuitable.Adequatetensilestrengthandductilitycanbeachievedutilizingacombinationofhightoolrotationalspeedofabout2000r/minandlowspeedofweldingaround28mm/min.Atverylowandhighdwelltimetheductilityofweldedjointsarereducedsignificantly.