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一、前言目前我国城市煤气输配工程主要使用铸铁管材。铸铁管材具有价格低,使用寿命长等优点。但我国目前所生产的铸铁管口型为承插式接口。该式接日是1785年为给排水而设计的,属刚性接口,一般允许折角0.5～1°;允许轴向拉伸值为0.06毫米。另外接口施工操作麻烦,劳动强度大。而且受操作水平限制,稍有不慎,往往造成验收不合格,需反复检漏,重新开挖,修补接口等。此外,这种接口对路面荷
I. Preface At present, China’s urban gas distribution project mainly uses cast iron pipe. Cast iron pipe has the advantages of low price and long service life. However, the cast iron nozzles currently produced in China are socket-type connectors. The formula is designed for water supply and drainage in 1785. It is a rigid interface and generally allows for a camber angle of 0.5 to 1°; the allowable axial extension is 0.06 mm. In addition, the interface construction operation is troublesome and labor intensity is great. Moreover, due to the limitation of the operation level, a slight carelessness often leads to unacceptable inspections, repeated leak detection, re-excavation, and repair of interfaces. In addition, this interface is used to load the pavement