نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران.
2 استاد گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران.
3 دانشیار گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه شهید مدنی آذربایجان، تبریز، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Tailings dams are structures used to store tailings from mineral and industrial processing. These dams play a vital role in controlling pollution and reducing the environmental impacts of mining activities. Generally, these dams are not built to their final level all at once and in one stage, but rather, as the extraction process progresses and the resulting tailings are produced, the height of these dams increases in stages. The Mazraeh copper mine tailings dam is a rockfill dam with a reservoir capacity of about 550,000 cubic meters, located in East-Azerbaijan province, 18 kilometers north of Ahar city and on the eastern side of the Shiver intrusive masses. The current level of the tailings dam after first construction and two stages of raising elevation is 2085 (meters above sea level) and about 50 meters above the bed, and the third stage of raising is currently being designed and is under construction to a height of 2095 meters. This dam is built on granite bedrock and the weathering of the rock mass at the surface and along the joints is assessed as low to moderate. The quality index of the rock mass up to a depth of 20 meters from the ground surface is very poor to poor and at greater depths it is moderate to excellent. In this paper, the variants for raising the dam crest level from 2085 to 2095 are examined and then, based on the results obtained and the existing limitations, the proposed option is selected and designed using Slope/W, Sigma/W and Plaxis software. Based on the results obtained, the use of upstream methods is an economical and risky option, the downstream option is uneconomical but safe, and the center-facing option is intermediate. Therefore, due to existing limitations and short-term operation period (about 10 years), the use of a combined method of the 5m centerline followed by 5m upstream method was proposed. The design results showed that the downstream slope in this case needs to be reduced from 1v:1.6h at the current state, to 1v:1.75h. The vertical displacement after the raising completion was estimated to be about 54 to 60 cm. For the closure and abandonment stage of the study tailings dam, it is recommended to reduce the downstream slope of the dam body and ensure that the tailings are consolidated and dried inside the reservoir (to prevent possible liquefaction).
کلیدواژه‌ها [English]
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