孔隙水压对充填体性能的影响

Effect of pore water pressure on the properties of backfill

为探究大水矿山充填体的力学性能变化,将充填体试块置入高压水体中使其内部形成孔隙水压,研究孔隙水压下充填体的抗压强度、抗拉强度和含水量等指标的变化。试验以孔隙水压、浸入时间、充填配比和料浆浓度为主要影响因素,开展29组充填体强度试验。方差分析表明,料浆浓度和充填配比对充填体抗压强度影响极显著,孔隙水压影响显著;浸入时间对充填抗拉强度影响显著。相同充填配比和料浆浓度下的充填体抗压和抗拉强度随孔隙水压和浸入时间增长而下降,其中抗拉强度下降幅度较大。充填体含水量随孔隙水压增大而增大,增长趋势和充填体强度增大趋势相吻合。

This paper studies changes of compressive strength,tensile strength and water content of backfill under pore water pressure which was produced by placing the backfill specimen into the high-pressure water.29 tests of backfill strength were conducted,which was affected by pore water pressure,curing time,mixture ratio and slurry concentration.The analysis of variance shows that slurry concentration and mixture ratio have extremely significant effect on the compressive strength of backfill which pore water pressure has significant effect on,and curing time has significant effect on the tensile strength of backfill.Under the same mixture ratio and slurry concentration,the compressive and tensile strength of backfill decrease with the increase of pore water pressure and curing time,and the tensile strength of backfill decreases significantly.The water content of backfill increases with the increase of pore water pressure,and the growth trend is consistent with the increasing strength of backfill.