Abstract
As the reserves of alluvial placers in river valleys are getting depleted, the importance of highland placers increases. In some cases, it is possible to use dredging for their development. Dredging is successfully applied to develop a highland placer of the Yakh- Suyskoye deposit located in northwestern Pamir at the altitude of 2000 m or more. A 380-liter dredge is used there. This deposit faces specific problems. They include steep slopes and narrowness of the valley, unevenness of the placer bedrock with lots of sharp bumps and dips, lots of boulders and dredging waste in the placer, adverse hydrogeological conditions that hamper the development and the maintenance of the water level. Due to this, the dredge operated in the semi-bank mode. Besides, the dredge aft was regularly displaced to dispel dredging wastes, which decreased the dredge performance while not being able to eliminate the bottom break hazard and the accumulation of dredging wastes in the pontoon. All of the above calls for the development of a new placer development technology that would prevent negative impacts. Based on the previous research, we developed and introduced a placer development technology stipulating the increase of the water level by 7 m. To this end, we constructed a dam on the waste piles below the dredge. The dam was 10 m high and 120 m wide. Since the permeability coefficient of the river Safet-Dora rocks is 75-80 m/day and that of the dredging waste piles is 500 m/day, the dam was equipped with polyethylene film sealing screens. This new dredging technology with a 7.5 m water level increase allowed us to process the site in one bank; eliminate the accumulation of dredging wastes at the pontoon aft and the risk of pontoon breakage on the bedrock bumps; increase the dredge operation time by 1.3 h/day; prevent river pollution; acquire significant economic benefits. Thus, we developed and introduced a relatively simple and efficient dredging technology for highland placers, which can be recommended for further use.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IOP Conference Series: Earth and Environmental Science
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
