旋挖成孔灌注桩在松散高填方地基中的应用

Application of Rotary Drilling Cast-in-place Pile in the Soft High Embankment

分析了重庆市松散高填方块石地基的工程特性,结合一工程案例,对目前该类地基常用的几种处理方案——灌浆法、强夯法、钻孔及冲孔成桩法进行了对比分析,探讨了各自的特点,针对高填方地基的特殊性,提出了旋挖成孔灌注工艺。介绍了旋挖成孔方法、特点及在重庆的应用现状,讨论了该工法在工程案例中采用干法和湿法的成桩效果,以及在破岩能力、钻进速度、泥浆护壁效果等方面的优缺点,提出了干作业施工中处理塌孔的技术措施,对山区建筑中类似填方工程有一定的借鉴意义。

This article analysed the engineering characteristic of soft high embankment in Chongqing,and a comparative analysis was carried out for several common foundation treatment plans—grouting,compaction,drilling and punching into the pile by a project case and their properties were discussed respectively.This paper proposed a technology of rotary drilling cast-in-place pile for the special nature of the high embankment,in further,introduced its drilling mode and feature and application status in Chongqing,probed into construction quality by dry and wet drilling methods and the advantages and disadvantages in terms of rock breaking,drilling speed,effect of slurry wall.In the end,a technical measure is proposed for treatment of hole collapse during the construction by dry drilling.It had a certain reference value for similar project.