Abstract:

The deflection accuracy of inclined shaft in intermediate coarse granite construction by raiseboring method is low. Hence, a new type of TDX1500 special drilling machine for oblique guide hole is developed by trajectorycontrol technology with highprecision, drilling machine combination and slurry protection technology for oblique guide hole; and a set of rapid, highefficient and accurate directional control technology for borehole of oblique guide hole with large dig angle constructed by raiseboring method is developed as well. The TDX1500 special drilling machine for oblique guide hole, newtype of 7LZ120 short screw drilling tool and SMWD76 wireless inclinometer are used in oblique section of #1 highpressure water diversion pipe of Fengning Pumpedstorage Hydropower Station; the shaft wall is protected by slurry; and a 302 mlong guide hole with dig angle of 53° and deflection of 0.42% is constructed; and the drilling real trajectory is highly fitted with the design trajectory, and the trajectory of oblique guide hole presents smoothly within the target area, and the technical parameters can fully meet the requirement of raiseboring construction.

Key words: pumpedstorage hydropower station, raiseboring method, inclined shaft with large dip angle, oblique guide hole, directional drilling