Successful Completion of Reaming at Changlongshan Project

Time£º2019/11/4 11:15:00    144  Browse

On 2 Sept 2019, a letter of congratulation was sent by Changlongshan Construction Unit of China Gezhouba Group Three Gorges Construction Engineering Co (hereinafter referred to as CGGC) appreciating the successful reaming of No.3 water diversion inclined shaft at Changlongshan Power Station, which is the third inclined shaft that JCHX Raise Boring Branch completed there, the total depth/length of three shafts was 1705m.
        Located at Tianhuangping Town, Anji County of Zhejiang Province, Changlongshan pumped-storage power plant is designed with 2100MW capacity consisting of six 350MW generators, and scheduled to be commissioned on 30 June 2021. The scope of works includes three water diversion inclined shafts, smoke shaft for power house, smoke shaft for main substation, air exhaust shaft etc; the key works and biggest challenge lie in three inclined shafts, each with an oblique length of 406m. Priority was given to No.1 inclined shaft for it’s on the critical path and having direct impact on the timelines of commissioning the first generating unit.
        Water delivery system, underground power house and reservoir were constructed by CGGC. Being aware of JCHX’s possession of TR-3000 raise boring machine and its successful completion of raises at Huanggou Hydropower Station, CGGC reached out to JCHX and chose JCHX among several competitors as the contractor for Changlongshan Project. In view of the complex geological condition, JCHX proposed to use directional drilling (pilot hole) plus raise boring method.
        Each of the three inclined shafts was designed with 415m depth at a gradient of 58°, and surrounded by hard rock with maximum compressive strength of 28mpa. Despite of big challenges, tight schedule, heavy work quantity, and requirement on high precision, all members demonstrated the spirit of fearlessness and spared no efforts to complete the tasks through the application of TR3000 raise boring machine, two sets of CY-120VD raise boring machines, and FDP-68 pilot drilling machine.