预应力管桩空腔+锚索组合抗拔桩施工技术应用

Application of Construction Technology of Prestressed Pipe Pile Cavity and Anchor Cable Combined Uplift Pile

针对桩基抗拔问题,考虑到抗拔结构在实际工程中的需要,并结合预应力管桩的特点,提出了一种引孔植入内置压力分散型锚索预应力组合抗拔管桩的施工技术。在预应力管桩沉桩过程中同步安装无粘结压力分散型预应力锚索,通过细石混凝土灌芯将拉拔力分散传递给管桩不同深度处,进而由管桩侧摩阻力承担,并且极限侧摩阻力通过管桩外侧及底部的高压注浆及高压旋喷得以提高。通过将该技术应用于实际抗浮桩基施工中,取得了较好的技术经济效益,降低了对周围地层的扰动影响,同时降低沉桩阻力,提高施工速度。

In order to solve the problem of pile foundation pull-out resistance,considering the need of pull-out resistance structure in actual engineering and combining the characteristics of prestressed piles,a construction technique of inserting built-in pressure-dispersion anchor cables in the pilot hole and installing non-bonded pressure-dispersion prestressing anchor cables synchronously during the pile settlement process is proposed,and the pull-out force is transferred to different depths of the pile through fine stone concrete cores.In turn,the lateral frictional resistance of the pile is borne by the pile,and the ultimate lateral frictional resistance is improved by high-pressure grouting and high-pressure spinning on the outside and bottom of the pile.By applying this technology to the actual anti-floating pile foundation construction,good technical and economic benefits are achieved,reducing the disturbance effect on the surrounding stratum,while reducing the resistance to pile sinking and increasing the construction speed.