ROTARY DRILLING RIG FOR CAST-IN-SITU TUBULAR PILE AND PILING METHOD THEREOF

摘要

A rotary drilling rig for cast-in-situ tubular pile comprises a first drilling rod (1) and a drilling bucket (6) arranged at the bottom of the first drilling rod. The first drilling rod is tubular; the drilling bucket is annular and includes a concentric inner annular wall (8) and an outer annular wall (7). An annular hole (9) is formed between the inner annular wall (8) and the outer annular wall (7). The first drilling rod is concentric with the inner and outer annular wall. The inside diameter of the first drilling rod is more than or equal to that of the inner annular wall and the outside diameter of the first drilling rod is less than or equal to that of the outer annular wall. A piling method includes the following steps: piling with the rotary drilling rig for cast-in-situ tubular pile; forming an annular hole in the ground; repeating rotary drilling until the depth of the annular hole reaches the predetermined depth; casting concrete into the annular hole; forming the tubular pile finally. A joint comprises an upper end surface for connecting with a power head and a lower end surface for connecting with an assembled rod, and the upper, lower end surface are connected with a frusto-cone. The drilling rig can forms an annular hole through rotary drilling, and has the advantages of high construction speed, large diameter of the construction cylinder, deep construction depth, good economy and high bearing capacity.