某钻机队在海口海瑞大桥工地用SPJ３００型钻机进行钻孔施工，桩基为摩擦桩，设计孔径１．５m、孔深４６．５m。在钻进到４４m时，笼式钻头与钻杆脱落掉入孔中。打捞钻头还算顺利，可用于打捞钻头的“鱼尾器”（直径不足６０cm螺旋状半圆形钩构件）却落在孔底。由于该构件为半 A drilling rig construction site in Haikou, Haikou, with SPJ300-type drilling rig construction, pile friction pile, the design aperture of 1.5m, hole depth 46.5m. When drilling to 44m, the cage bit and the drill pipe fall off into the hole. The salvage bit went well and the “fishtail” (less than 60 cm diameter helical semicircular hook member) that could be used to retrieve the bit fell on the bottom of the hole. Because the member is half