全尾砂-废石混合回填膏体流动特性变化规律  

The change laws of flow characteristics of backfill paste mixed by unclassified tailings and waste rock

作　　者：孙伟[1,2] 吴爱祥[1,2] 王洪江[1,2] 周喻[1,2] 熊有为[3] 仪海豹[4] 

机构地区：[1]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083 [2]北京科技大学土木与环境工程学院,北京100083 [3]长沙有色冶金设计研究院,长沙410011 [4]中钢集团马鞍山矿山研究院有限公司,安徽马鞍山243004

出　　处：《岩土力学》2013年第12期3464-3470,共7页Rock and Soil Mechanics

基　　金：国家"十二五"科技支撑计划项目(No.2012BAB08B02);国家自然科学基金面上项目(No.51374034);长江学者和创新团队发展计划项目(No.IRT0950)

摘　　要：质量浓度、废石掺量是影响尾砂-废石混合回填体流动特性的主要因素，研究这些因素对膏体流动性的影响规律，对于控制膏体流动性具有重要意义。采用改进的小型直剪装置进行混合回填体直剪试验，以黏聚力、内摩擦角、抗剪强度为依据，综合得出了混合回填膏体流动性变化规律。试验结果表明，膏体在受力变形前期呈较为明显的似弹性性质，随废石掺量增加，位移-剪应力曲线中阶梯状变化趋势增加；回填体黏聚力取决于质量浓度，内摩擦角受质量浓度和废石掺量影响程度基本相同，两者协同作用；质量浓度在80％-88％范围时，黏聚力随质量浓度增大呈非线性增大，内摩擦角与质量浓度呈s型变化趋势；抗剪强度随质量浓度的增大而增加，在82％-84％区间抗剪强度变化显著，流动性出现突变。Mass fraction and waste rock proportion are main influence factors which affect flow characteristics of backfill paste mixed by unclassified railings and waste rock. To study of the influence law of these factors about paste flow characteristics may have important significance about controlling paste flow characteristics. Shear test of mixed backfilling is conducted with the improved small direct shear device and then get the change law of mixed backfilling. The test results show that paste presents approximate elastic at prophase of force-deformation and the stepladder trend in displacement-shear stress curve increases with the increase of waste rock proportion. Cohesion of paste depends on mass fraction and internal fraction angle is affected by mass fraction and waste rock proportion almost the same, and that is combined effect. When mass fraction in the range of 80%-88%, cohesion pretends as nonlinear growth with the increase of mass fraction, internal fraction angle and mass fraction presents S-type trend, shear strength increases with the increase of mass fraction and varies significantly when in the range of 82%-84%; at the same time, flow characteristics is mutation.

关 键 词：塌陷区 混合回填体 流动特性 全尾砂-废石 膏体 

分 类 号：TD853[矿业工程—金属矿开采] TD88[矿业工程—矿山开采]