Secondary shaft completion construction method based on raise boring process

A secondary shaft completion construction method based on a raise boring process, comprising the following steps:

• Step 1, carrying out construction of a directional boring hole (8):
• excavating a tunnel (1) in an underground rock body in advance, arranging and installing a directional boring machine (3) on the ground corresponding to the tunnel (1), installing a composite boring rod (5) and a directional boring bit (4) on the directional boring machine (3), drilling into the stratum along a design direction of a vertical/inclined shaft and penetrating through the stratum, communicating with the tunnel (1) to complete the construction of directional boring hole (8), and then withdrawing the composite boring rod (5);
• Step 2, measuring a deviation of the directional boring hole (8):
• measuring a maximum deviation distance δ between an axis of the directional boring hole (8) and a designed central axis of a vertical/inclined shaft (6);
• Step 3, carrying out construction of a pilot hole (12):
• disassembling the directional boring machine (3), installing a raise boring machine (9), connecting a small raise boring rod (10) with a reamer bit (11), carrying out secondary hole brushing by drilling the reamer bit (11) from top to bottom along a directional boring hole (8) to form a pilot hole (12), and ensuring that the small raise boring rod (10) is not withdrawn;
• Step 4, carrying out construction of a pilot shaft (14):
• selecting a small raise boring bit (13) with a radius of r, in which r>δ is ensured, disassembling the reamer bit (11), replacing the reamer bit and installing the small raise boring bit (13) at an end of the small raise boring rod (10), withdrawing the small raise boring rod (10) to drive the small raise boring bit (13) to reversely excavate the stratum, and excavating along the direction of the pilot hole (12) to form a pilot shaft (14);
• Step 5, carrying out construction of the vertical/inclined shaft (17):
• disassembling the small raise boring bit (13) and the small raise boring rod (10), lowering a large raise boring rod (15) to the tunnel (1) along the design direction of the vertical/inclined shaft, installing a large raise boring bit (16) on the head of the large raise boring rod (15), withdrawing the large raise boring rod (15) by the raise boring machine (9), driving the large raise boring bit (16) to reversely excavate the stratum along the designed central axis of the vertical/inclined shaft (6), and forming the vertical/inclined shaft (17) at one time according to a designed excavation line of a vertical/inclined shaft (7).