Application of long spiral drilled press-grouting super-fluid concrete foundation pile;

The industrial test, including three kinds of drilling technological methods, continuous flight auger boring, ramming and displacing drilling, pneumatic percussive rotary drilling, proved that it s all technical parameters have been strictly examined, the rigs designing quality requirements had been fulfilled and it can suit the needs of our country s anchor con.

The paper discussed the reasons of bored hole collapsing in sandy aquifer construction with long-spiral driller and the technological principle of wall protection with grouting under-borehole with an engineering case;and also introduced the application and effect of this technology in long-spiral bored cast-in-situ pile,the application limit for long-spiral bored hole pile was broadened.