But some kind of defects such ad gapping, broaching, break, separation were usually found in bored cast-in-place piles, which maybe reduces bearing value of pile and does harm to the superstructure.

• 但是许多机械成孔的灌注桩常出现缩颈、扩颈、断裂、离析等缺陷，影响桩基承载力及上部结构的安全，严重者甚至使桩失去承载力。