阳泉矿区自燃煤矸石山绿化中覆盖层碾压效果试验

自燃煤矸石山是矿区环境主要的污染源之一,对其实施封闭并绿化,需要构建具备一定阻隔空气能力的覆盖层,而覆盖层多为土质材料经碾压构成,空气阻隔性受其碾压质量的影响。结合阳泉三矿煤矸石山治理现场进行野外碾压试验,研究了煤矸石山现场碾压工具及碾压条件下的压实效果。通过对不同铺土厚度的黄土进行碾压,测定紧实度和干密度来表征碾压效果,分析以压实度(85%)作为压实质量控制标准的条件下合理的碾压工程参数。结果表明,利用现场自制碾磙(4t)进行平碾碾压,浅部土层受到碾压遍数的影响较大,深部土层受到碾压遍数的影响较小,其特征深度在15—25cm;建议的施工方案及碾压参数为:含水量接近最优含水率(相差不超过±2%),松铺厚度20~40cm,碾压3~5遍。

An Experiment on Rolling Compaction Effect of Covering Layer on Coal Gangue Pile with Spontaneous Combustion in Yangquan City

Spontaneous combustion of coal gangue hill is one of the main environmental pollution sources in mining area. To seal and afforest the coal gangue, a covering layer with a certain air barrier property is needed. The covering layer is made of soil materials by rolling compaction and thus the performance of air barrier depends on rolling quality. The compaction effect in relation to rolling tool and the rolling conditions of field coal gangue was studied by combining on-site compaction test for coal gangue dump governance in the Yangquan 3rd coal mine. Based on the rolling compaction experiment on the loess of various thicknesses, soil rigidity and dry density were measured to illustrate the rolling effect and the reasonable rolling parameters were analyzed under the condition that the degree of compaction(85%) was used as the compacted quality control standard. By utilizing the self-made grinding roller(4 t) for flat rolling, results show that shallow soil was more sensitive to rolling frequency in comparison with deep soil, and its corresponding depth was about 15-25 cm. The suggested construction proposal and rolling parameters are that moisture content is close to the optimum rate of water content (between±2%), loose paving thickness is 20-40 cm, and the material is compacted by 3~5 times rolling.