On May 13, the development of pilot hole of 3# inclined shaft at Qingyuan Project constructed by JCHX Raise Boring Division was successfully completed, with a deviation of merely 0.07%, hitting the record low.
The 299m-deep 3# inclined shaft is designed to be developed by TR3000 boring machine, with reaming hole being Φ2.4m and inclined angle being 55°. The project team consists of young talents with college degree and averaging at 25. After years of practice, they become more experienced and skilled, which makes the remarkable achievement at Qingyuan project possible.
As the 3rd inclined shaft with a depth of 299m constructed by the Raise Boring Division at Qingyuan pumped-storage power station, it was developed in a stable and organized manner. Advance preparations were done by the crew, including the preparation of workfaces, inclination measuring tools and other accessories, which laid a solid foundation for subsequent works.
During construction, various measures were taken by the crew to guarantee work precision, including equipment commissioning, boring machine installation data analysis, properly placing of drill rod stabilizer, suitable selection of drill rod and accessories, strict implementation of inclination measuring plan and appropriate adjustment of rod stabilizer. Besides, diverse factors have been taken into consideration, such as actual rock conditions, existing inclination measuring data and construction experience accumulated during the development of previous two inclined shafts.
Inclination was measured for 4 times with rod stabilizer adjusted twice. Actually the deviation has already met the Client’s requirement after the first adjustment, but the crew applied a second adjustment to further improve precision. Finally, the pilot hole of the 3# inclined shaft was developed with a record-breaking deviation of merely 0.07%.
JCHX Raise Boring Division has always endeavored to enhance work quality and to develop raises with high precision. An excellent raise development team has been organized to deliver first-class services with superb technologies and efficiencies.
