地震-降雨作用下铀尾矿库滩面氡析出响应规律研究

Response Law of Radon Exhalation from Beach Surface of Uranium Tailings Pond Under the Earthquake-Rainfall Effect

受地震和降雨的影响,对我国南方铀尾矿库滩面氡析出规律研究十分重要。选取我国南方某铀尾矿库的铀尾砂样品,制备了1.0 m×1.0 m×0.8 m分层压实的铀尾矿库滩面缩尺模型,运用自主研制的大型自然灾害综合模拟试验装置,探究了地震-降雨作用下铀尾矿库滩面氡析出率的变化规律。试验结果表明,在模拟地震峰值加速度一定的条件下,随模拟降雨量的增加,红土覆盖层表面裂隙的发育、扩张愈发明显;覆盖层表面氡析出率呈现出先降后升的趋势,在模拟降雨量为中雨(12.5 mm/24 h)时达到最低;通过灰色关联分析可知,降雨量较地震峰值加速度对表面氡析出率的影响更大。因此,合理设计铀尾矿库滩面排洪系统并严格落实滩面防洪措施显得更为重要。

Affected by earthquake-rainfall effect, it is very important to study the response laws of radon exhalation from the beach surface of uranium tailings pond in South China. The uranium tailings samples from an uranium tailings pond in South China were selected, and a scale model of beach surface of uranium tailings pond compacted in layers was prepared as the size of 1.0 m×1.0 m×0.8 m. The variation law of radon exhalation rate on the beach surface of uranium tailings pond under the earthquake-rainfall effect was explored by self-developed large-scale natural disaster comprehensive simulation test device. The test results show that, under the condition of a certain simulated seismic peak acceleration, the development and expansion of cracks on the surface of laterite overburden become more and more obvious with the increase of simulated rainfall. The radon exhalation rate on the surface of the overburden shows a trend of decreasing first and then increasing, and reaches the lowest when the simulated rainfall is moderate rain(12.5 mm/24 h). According to the grey relational analysis, rainfall has a greater impact on surface radon exhalation rate compared with the earthquake peak acceleration. Therefore, it is more important to reasonably design the flood drainage system of beach surface of the uranium tailings pond and strictly implement the flood control measures of beach surface.