沉管法在合浦县西山倒虹吸工程中的运用

Application of immersed tube method in Xishan inverted siphon project of Hepu County

合浦县西山倒虹吸为总江水闸灌区南域支渠跨南流江的渠系建筑物,倒虹吸输水涵管跨江处基础为砾砂层,层厚3~4 m,砾砂层以下为砂卵砾石层,基础透水率大,采用土石围堰分期导流施工时基础处理投资较大且工期较长。经充分论证及参考已有工程经验,本工程采用沉管法对中央河床段的输水涵管进行施工,介绍了沉管法的施工工序及施工工艺。

Xishan inverted siphon project of Hepu County is one of the components of the sub-channel across Nanliu River, in the southern area of Zongjiang Gate Irrigation Zone. The foundation of the inverted siphon culvert across river is gravel layer of 3~4 m thick and sandy gravel layer below with large water permeability. The construction scheme of earth-rock cofferdam and staged diversion will render high foundation treatment cost and long construction period. Based on ample discussion and with reference to experience of similar projects, the culvert in the middle of river bed was constructed by immersed tube method. An introduction was made on the construction procedures and technique.