掺纤维分层胶结充填体抗弯性能试验研究OA

The downward drift filling mining method uses the filling body as an artificial false roof to bear the upper load.However,this kind of cemented filling body is prone to bending failure under stress,which has a negative impact on the safety of mining operations.In order to improve the structural stability of cemented backfill,based on the con-trol variable method,three-point bending test was carried out to investigate the effects of curing age,cement-sand ratio and height of intermediate layer,fiber content and length on the flexural performance of layered cemented back-fill.The results show that the bending strength and fracture energy of the filling body increase with the extension of the curing age.The decrease of the cement-sand ratio of the middle layer will lead to the decrease of the bending strength and fracture energy.The height of the middle layer has a linear negative correlation with the fracture energy and bending strength.When the fiber content is 1%-2%and the length is 6-12 mm,the bending strength and frac-ture energy of the filling body are better.By reasonably regulating the curing age,intermediate layer and fiber parame-ters,the bending resistance of layered cemented backfill can be effectively improved.