根据工程实例 ,通过钻头和钻进工艺的对比试验 ,得出了利用大直径滚刀钻头 ,在致密卵漂石地层施工大口径桩孔 ,能大幅度提高钻进效率。 According to the engineering example, through the comparative test between drill bit and drilling technology, it is concluded that the use of large diameter hob bit to construct large diameter pile hole in the dense pebble stratum can greatly improve the drilling efficiency.