高水压作用下的球墨铸铁管道弯头支撑设计

Design on Pipe Bend Support of Ductile Iron under High Water Pressure

在高水压的作用下,球墨铸铁管道弯头处需设置支撑,一般均采用混凝土支墩的形式,尺寸非常大,需要占用较大的空间,而施工现场往往无法容纳较大尺寸的支墩。为满足现场使用条件,必须因地制宜地设计管道弯头支撑。研究采用了多种形式的支墩和接头形式,保证了管道安全:通过在支墩后背底部设置底坎,可增强支墩的稳定性,减小支墩混凝土方量;通过设置拉锚式支墩或桩锚式支墩,可将弯头压力传递至锚固支墩或桩基;采用TF自锚式接口、Xanchor自锚式接口或锯齿形橡胶圈,使管节之间既能保持柔性连接,又具备刚性连接的特点,通过管道与周围土体之间的摩阻力抵抗弯头处的水压外推力,避免设置支墩。

Brace must be set at bend of ductile iron pipes under high water pressure. Concrete buttress which has large size and occupy large space is widely used to support the pipeline. While site construction conditions is unable to accommodate larger size buttress, and the brace must be designed according to local conditions. Various types of buttress and joint were designed to ensure pipeline safety. The stability of buttress was enhanced and the volume was reduced by setting bottom sill at the back. Anchorage buttress or pile-anchorage buttress could transfer bend force to anchorage or pile foundation. TF self-anchored joint, X-anchor joint, jagged rubber ring were adopted to maintain flexible connection with characteristics of rigid connection, while the hydraulic bend force was resisted by friction between pipe and surrounding soil to avoid installation of buttress.