基于正交试验的胶结充填体力学性能及配比优化方案研究

Study on Mechanical Property and Proportion Optimization of Cemented Filling Body Based on Orthogonal Test

为了提出充填体的配比优化方案,以保证充填后采场采空区的稳定性。从充填体力学性能入手,通过正交试验,选取灰砂比、养护龄期与浓度作为影响因素,分析了充填体力学曲线的变化特征;基于极差分析方法,研究了3因素对充填体强度、弹性模量影响的主次顺序。研究表明:充填体的力学曲线存在明显的压密过程,当养护龄期较短时,曲线出现了显著的屈服平台,此时充填体的延性最强,残余强度最低,极限应变值最大。3种因素在影响充填体强度及弹性模量的敏感性上,主次因素序列为:Y(龄期)>X(配比)>Z(浓度),养护龄期在影响充填体力学性能中起主导作用,确定了最优配比方案为灰砂比1∶4、养护龄期28d、浓度74%。研究成果对矿山选择合理的充填材料配比具有参考价值。

In order to propose an optimized proportion scheme of the filling body,and to guarantee the goaf stability after filling,starting with the mechanical property of filling body,the cement-sand ratio,curing period and concentration were selected as the influencing factors through orthogonal test.The variation characteristics of mechanics curve for filling body were analyzed.Based on the range analysis method,the influence order of above three factors on the strength and elastic modulus of filling body was studied.The results showed that there was an obvious compaction process in the mechanical curve of the filling body.When the curing period was short,a significant yield terrace appeared in the curve.And at this time,the ductility of the filling body was the strongest,the residual strength was the lowest,and the limit strain value was the largest.At the sensitivity of three factors to the strength and elastic modulus of filling body,the sequence of primary and secondary factors was:Y(curing period)>X(cement-sand ratio)>Z(concentration).The curing period played a leading role in affecting mechanical property of filling body.The optimum proportion were obtained as the cement-sand ratio of 1∶4,the curing period of 28 days,and the concentration of 74%.The research results had a reference value for the mine to select the reasonable filling material proportion.