基于宏微观耦合分析胶结充填体强度差异的研究

Study on the strength difference of cemented backfill based on macro-micro coupling analysis

在高阶段采场充填过程中,井下原位取芯样品强度远远高于地表实验室试件。本文选取了李楼铁矿6个高阶段充填采场取芯样品,发现井下原位取芯强度比地表充填试件高1.59 MPa。通过电镜扫描和能谱分析,确定了胶结充填体内部的水化产物成分,进一步分析了全尾砂充填料浆固结演化过程。基于充填体的宏微观试验,对井下原位强度与地表试件的差异性进行耦合分析,揭示了自重压力对充填体的宏观力学性能和微观孔隙结构的作用机理。研究成果可为高阶段采场进一步降低灰砂比提供理论依据。

In the filling process of high stage stope,the strength of in-situ coring samples was much higher than that of the laboratory test blocks.The coring samples of 6 high stage filling stope in Lilou iron mine were selected in this paper and it was found that the in-situ coring strength was 1.59 MPa higher than that of the laboratory-cured specimens.The composition of hydration products in cemented backfill was determined by SEM and energy spectrum analysis,and the consolidation process of the unclassified tailing slurry was further analyzed.Based on the macro-micro test of the backfill,a coupling analysis of the strength difference between in-situ coring samples and laboratory-cured specimens was performed,and the mechanism of self weight pressure on the macro-mechanical properties and micro-pore structure of the backfill was revealed.The research results can provide a theoretical basis for further reducing the cement-sand ratio in the high stage stope.