冲击作用下铀尾矿坝损伤与氡析出规律

Damage of Uranium Tailings Dam and Radon Emission under Impact

冲击损伤会破坏铀尾矿坝体结构,给周边及下游人身财产安全带来潜在危害。通过自研水平冲击试验台开展铀尾矿库坝体冲击模拟试验,研究冲击速度逐级加载下坝体损伤特征及其坝体损伤氡析出规律。结果表明,冲击对坝体的损伤主要表现为表面单主裂隙发育和穿透破坏,穿透深度随冲击速度的增加而增加,红土层穿透破坏后的穿透深度的变化速度增大;红土层穿透前的氡浓度累积增长速率快于穿透后,穿透深度与整体氡析出率的规律呈现为缓慢上升(OA)-快速上升(AB)-趋于平稳(BC);穿透深度与降氡系数之间呈现快速下降到趋于平稳的规律,在红土层穿透后的3~7 cm穿透区间内降氡系数变化仅为2.94%。其结果可为铀尾矿库坝体安全稳定性研究提供参考。

Impact damage will destroy the structure of uranium tailings dam,and bring potential harm to the safety of people and property around and downstream.In this paper,the impact simulation experiment of uranium tailings dam is carried out through the self-developed horizontal impact test bench to study the damage characteristics of the dam and the radon emission law of the dam damage under the progressive loading of impact velocity.The experimental results show that the impact damage to the dam body is mainly manifested by the development of single main cracks on the surface and the penetration failure.The penetration depth increases with the increase of impact speed,and the change speed of the penetration depth after the penetration failure of the laterite layer increases.The cumulative growth rate of radon concentration before the penetration of laterite layer is faster than that after the penetration,and the law of penetration depth and overall radon exhalation rate presents a slow rise(OA)-rapid rise(AB)-stable trend(BC).The relationship between the penetration depth and the radon reduction coefficient shows a rule of rapid decline to a stable trend,and the variation of the radon reduction coefficient is only 2.94%in the 3—7 cm penetration interval after the laterite layer penetration.The results can provide a reference for the study of safety and stability of uranium tailings dam.