硬切削咬合桩施工工艺研究

Study on Hard Cutting Secant Pile Construction Technology

为解决地下存在卵石层、风化岩、砂层时,止水方法选择和施工难度大的问题,运用了硬切削咬合桩施工工艺。施工时,先进行素混凝土桩的施工,等素混凝土有一定强度后,再进行钢筋混凝土桩的施工。采用常规的旋挖钻机钻进,泥浆护壁措施,不需要全套管跟进。采用钻头直接对素桩进行切割,在素桩上形成圆弧形凹槽,从而实现素混凝土桩与钢筋混凝土桩的咬合,形成混凝土帷幕以达到止水、挡水的目的。现场施工表明,咬合桩的咬合效果和止水效果良好,工作效率得到了很大提高,该工艺可以推广到适合旋挖钻机施工的所有地层。

To solve problems of water sealing method option in subterranean pebble bed,weathered rock and sand layer as well as difficulties in construction,the hard cutting secant pile construction technology has been selected. During the construction,plain concrete pile is firstly proceeded; until the plain concrete achieved certain strength,and then carried out reinforced concrete pile construction.Using conventional rotary rig in drilling,mud slurry wall protection,need not full casing follow up,cut the plain concrete pile through drilling bit directly will form a circular arc groove,thus has realized plain concrete pile and reinforced concrete pile holding-on; finally can form a concrete curtain and achieve water sealing and resisting. The site construction has shown that the holding-on and water sealing results are excellent; work efficiency has been greatly improved. The technology can be popularized to all strata propitious to rotary drilling rig operation.