考虑充填高度和龄期的超细尾矿胶结充填体强度演变模型

Strength evolution model of ultra-fine tailings cemented paste backfill considering filling height and curing age

目的:受固结应力的影响,采场不同位置的充填体强度存在较大差异。为精细化指导矿山充填作业,需构建考虑充填高度和龄期的充填体强度演变模型。方法:以超细尾矿胶结充填体为研究对象,通过提取不同充填高度处的充填体试样,分析了弹性模量、泊松比及抗压强度随充填高度和龄期的变化规律。结果:充填体的弹性模量随着充填高度和龄期的增长而逐渐增大,而泊松比相反;充填体弹性模量、泊松比和抗压强度随充填高度和龄期的变化均符合指数函数的发展规律;考虑充填高度和龄期的充填体抗压强度演变模型可以用相乘模式的双指数模型进行评估,模型计算值与试验值的误差在10%以内。结论:该强度演变模型的建立,可为矿山充填结构的稳定性评估提供更精确的模型参数。

Purpose:Due to the influence of consolidation stress,the strength of backfill in different positions of the stope is quite different.In order to guide mine filling operation in a fine way,it is necessary to build a strength evolution model of cemented paste backfill(CPB)considering filling height and age.Method:Taking superfine tailing CPB as the research object,the variation law of elastic modulus,Poisson′s ratio and compressive strength with filling height and age was analyzed by extracting CPB samples at different filling heights.Result:The elastic modulus of the CPB increases gradually with the increase of filling height and age,while Poisson′s ratio is opposite.The changes of elastic modulus,Poisson′s ratio and compressive strength of f CPB with filling height and age all conform to the development law of exponential function.The evolution model of compressive strength of CPB considering filling height and age can be evaluated by the double exponential model of multiplication mode.The error between the calculated value of the model and the experimental value is within 10%.Conclusion:The establishment of the strength evolution model can provide more accurate model parameters for the stability evaluation of the mine filling structure.