胶结充填体强度敏感性分析及灰砂比优化

以李楼铁矿尾砂为原材料，采用水泥作为胶结材料，制作尾砂胶结充填体，进行尾砂基本物理化学参数和单轴抗压强度的测定。研究了尾砂胶结充填体强度与料浆浓度、灰砂比及养护龄期之间的关系，并对敏感性进行了分析。胶结充填体强度随着料浆浓度的增加呈线性增长，随灰砂比和养护龄期的增长呈指数增长。胶结充填体对灰砂比的敏感性最高，养护龄期次之，料浆浓度最低。在工程应用中，对6个大型充填采场的胶结充填体取芯强度进行分析，采场取芯强度比实验室试块强度高1.59 MPa，在满足采场不同段高强度的基础上，20～50 m部位充填配比由1∶6降为1∶8，进而降低充填成本。

Sensitivity Analysis of Strength of Cemented Backfill and Ratio of Optimization

Cemented backfills were produced by taking Lilou iron ore tailings as raw material and cement as cementing material. The physical and chemical parameters and the uniaxial compressive strength of Lilou tailings were measured. The rela-tionship of the cemented backfills' strength with slurry concentration,cement-sand ratio and curing age were studied and the sensitivity was analyzed to these impact factors. The strength of the cemented backfills follows a linear growth with slurry con-centration,but an exponential growth with cement-sand ratio and curing age. Moreover,the sensitivity of the backfills' strength to cement-sand ratio is the highest,but is the weakest to slurry concentration. In engineering application,the core strength de-rived from six large filling stopes was analyzed. The underground core strength was above 1. 59 MPa higher than laboratory test blocks. In order to satisfy the strength of different depth,it is suggested that filling ratio should be reduced from1:6 to 1:8 at 20~50 m segment,thus lowering the filling costs.