钻孔灌注桩在富水砂性土层中的应用

Application of bored pile in water-rich sandy soil

钻孔灌注桩是一种常用的地基加固方法,如何有效控制灌注桩成孔后的稳定性,对于保证灌注桩整体成桩质量至关重要。以沿海地区某项目为例,针对长螺旋钻孔灌注桩在富水砂性土层施工中遇到的成孔效率低、孔底涌土等问题,提出了采用钻孔成孔后同步进行孔底注水的施工方法,并进行试桩验证。结果表明:孔底注水能有效地解决成孔后孔底涌土的问题。使用长螺旋钻孔灌注桩孔底注水技术既能降低工程造价,又能保证施工质量、发挥长螺旋钻机施工效率高的特点,具有良好的实用性。

Bored pile technology is a common method of foundation reinforcement.How to effectively control the stability of bored piles after drilling is very important to ensure the integral quality of bored piles.Taking a project in coastal area as an example,aiming at the problems of low hole-forming efficiency and soil gushing at the bottom of the hole encountered in the construction of long spiral bored pile in water-rich sandy soil layer,the construction method of synchronous water-filling at the bottom of the hole after drilling is put forward and is verified by pile test.The result shows that water injection at the bottom of the hole can effectively solve the problem of soil gushing at the bottom of the hole after drilling.Using the bottom water injection technology of long screw bored pile can not only reduce the cost of construction,but also ensure the quality of construction and give full play to the characteristics of high construction efficiency of long screw drilling rig,therefore have good practicability.