Successful Breakthrough of Outgoing Shaft at Wendeng Pumped-Storage Power Plant
Time£º2019/11/4 11:17:00 518 Browse
On 7 Oct 2019, successful breakthrough of outgoing shaft was achieved by JCHX Raising Boring Branch at Wendeng Pumped-Storage Power Plant.
The shaft is designed with 278m depth, 3.1m net diameter at 90° angle. The unique rock formation poses big challenges to the works, especially with maximum compressive strength of 28mpa; pilot drilling and reaming were both threatened under the circumstances of hard rock, faults and sand beds, not to mention challenge from big size of the hole.
JCHX utilized CX-6C fiber optic gyroscope inclinometer for survey at first 20m and then at 30m intervals, to keep the centerline of the completed shaft within tolerance limit; the final deviation was merely 20cm compared to the designed centerline.
Hard rock hob was utilized to cope with the challenges in reaming, and technical management was strengthened to reduce abrasion of hob, owing to which the hob was changed only twice during the whole reaming process and breakthrough was achieved successfully.