三弦式转换桁架施工技术

Construction Technology of Three-string Transfer Truss

双弦式转换结构弦杆的梁截面与梁式和板式转换结构相比,具有截面小、自重轻、节省建筑立面空间等优点。详细介绍了一种新型桁架系统——三弦式转换桁架,这种桁架比双弦式转换桁架更先进,能使上部结构荷载由上、中、下3根弦杆及两层斜腹杆共同转换承担;且下弦杆采用预应力梁,使整个结构体系的杆件截面更小、更节省建筑空间。介绍了该转换桁架施工技术,主要包括模板工程、钢筋工程、混凝土工程、预应力工程等方面,与普通转换大梁相比施工更加复杂,需要综合多工种共同配合。

Compared with beam and plate transfer structure, the beam section of double-string transfer structure has advantages such as small section,light weight and saving building space. A new type of truss system named three-string transfer is introduced in this paper,which is more advanced than double-string ones.The three chords and two tilted belly poles of this system can bear upper loads.Besides,prestressed beams are adopted in below string bars,which can make section area smaller and make building space saved.The construction technologies are outlined including formwork engineering,steel bar engineering,concrete engineering,and prestressed engineering.Compared with common transfer beam,this system is more complex with help of comprehensive jobs together.