基于PFC的废石胶结充填体破坏规律研究

Study on the failure law of cemented waste rock backfills based on PFC

为研究不同灰砂比下废石胶结充填体的破坏规律,对其进行了单轴压缩试验。结果表明,废石胶结充填体试样的失稳方式分为张开式和剪切式;在废石胶结充填体试样的峰值前应力—应变关系上,灰砂比对发生张开式失稳的试样影响较大,而对发生剪切式失稳的试样影响较小。运用基于细观颗粒流理论的PFC程序对废石胶结充填体模型进行单轴压缩模拟。结果表明,在应力—应变关系上,模拟结果与试验结果相一致;通过模型内部废石的位移情况可以揭示不同灰砂比下废石胶结充填体的失稳规律;通过粘结力分布情况得到废石胶结充填体不同失稳方式的原因。因此,PFC可以很好地应用于充填材料的选择与优化。

In order to study the failure law of cemented waste rock backfills with various cement-sand ratios, uniaxial compression test is carried out. The results show that the failure mode of cemented waste rock backfills specimen can be divided into tensor failure and shear failure. Specimens with tensor failure can be greatly affected by cement-sand ratio on the stress-strain relationship of pre peak. In order to simulate the influence on the failure law of cemented waste rock backfills caused by cement-sand ratio in uniaxial compression test, PFC is used. The results show that the simulated results are consistent with the experimental results on the stress-strain relationship. The failure law of cemented waste rock backfills with various cement sand ratios can be revealed by the displacement of waste rocks in models. The reasons of different failure modes of cemented waste rock backfills can be revealed by the distribution of connect force. Therefore, PFC can be used in selection and optimization of filling materials.