According to the results of six in-situ pile load tests of boring cast-in-situ piles after grouting at the piles tips and the tress distributions of three of those piles,theirQ-scurves,tress transferring of piles,pile side frictions and pile tip resistances affected by grouting,were analyzed in details.

Based on the results of statical load test of pile and the plate loading test of deep layer,the paper has analysed the tip resistace of an artificial digging hole pile taking gravel sand layer as bearing bed and discussed potentialities of its ground and then the eigenvalue of pile tip resistance is put forward.

By static loading test and field test of loading transmission the influence of slime at pile botton to ultimate bearing capacity, pile tip resistance, side friction of pile are analyzed and effective measures are also proposed.

Mobilization of toe resistance of piles with local displacement in sand;

These factors,which include slurry s preparation,circulation,depuration and so on,would influence drilling speed,bore quality,exertion of pile shaft resistance and base resistance.