黄土-废石胶结充填体抗压强度试验研究

Experimental Study on the Compressive Strength of the Backfills from Cemented Waste Rock with Cement and Loess

宝山矿2#砂页岩矿体采用黄土-废石胶结充填法回采。为了确定其合适的配合比,采用RMT-150B岩石力学试验机对七种配合比的黄土-废石胶结充填体的标准试样进行了抗压强度测试,利用测试结果选择C组配合比的黄土-废石胶结充填体应用于该矿工业性试验采场进行充填,并对该试验采场的充填体进行了应力测试。研究结果表明:黄土-废石胶结充填体的破坏过程分为五个破坏阶段;黄土-废石胶结充填体的强度随黄土加入量的增加而减小,随水泥加入量的增加而增加;初期强度随水泥加入量的增加而提高;选用C组配合比的黄土-废石胶结充填体充填试验采场的应力为2.25 MPa,其龄期为60 d时为原岩体的抗压强度的47.4%,满足该矿对充填体强度的要求;研究成果为其它采场选用合适的胶结充填体的配合比提供了依据。

The ore body in the Baoshan mine is a complicated one and the cut and fill method is to be used to recover it and the cemented waste rock with cement and loess is to be used as the backfill.In order to determine the feasibility of the mixture ratios of the cemented waste rock with cement and loess,the compressive strengths of the backfills with different mixture ratios at different solidification durations were measured using RMT-150B servo-controlled machine for rock testing.Based on the test results,the backfill with C mixture ratio was used to the cut and fill method,and stress measurements were conducted for the backfill.The results show that the failure process of the cemented waste rock with cement and loess was divided into five stages,that the compressive strength of the backfill decreased with the increase of the loess,that the compressive strength and the initial strength of the backfill increased with the decrease of the cement,that the stress of the test stope filled with C mixture ratio was 2.25 MPa and it made up 47.4 percent of the compressive strength of the backfill at the solidification duration of 28 days,that the research results of the backfill with C mixture ratio provided evidence for other stopes.