Abstract

To reveal the function of drilling pressure relief (DPR) in preventing rockbursts from the energy storage perspective, we investigated the rockburst proneness of red sandstone with different number and arrangement of prefabricated borehole via uniaxial compression tests. The experimental result revealed the failure intensity characteristics of specimen can be quantitatively described using the peak-strength strain energy storage index (PESI). The PESI of red sandstone specimens with boreholes decreased by 23.2%–70.2% compared with that of intact specimens, i.e. DPR can effectively reduce the rockburst proneness of rocks. Furthermore, the effects of the number and arrangement of boreholes on rockburst proneness were evaluated. The PESI decreased as the number of boreholes increased. When the arrangement angle with the loading direction changed from 90° to 27° and then to 0°, the PESI first decreased and then increased; when the arrangement angle with the loading direction was 27°, the efficiency of eliminating rockburst proneness and weakening peak compression strength was the best. The borehole arrangement angle affects rockburst proneness more than the number of boreholes does. This paper offers a novel approach of quantitatively evaluating the rockburst proneness of rocks after DPR and clarifies the effectiveness DPR in reducing the probability of rockbursts.

摘要

为了从储能的角度揭示钻井减压（DPR）在预防岩爆中的作用，我们通过单轴压缩试验研究了不同数量和排列预制钻孔的红砂岩的岩爆倾向。实验结果表明，试样的破坏强度特征可以用峰值强度应变储能指数（PESI）进行定量描述。钻孔红砂岩标本的PESI比完整标本的PESI下降了23.2%～70.2%，即DPR可以有效降低岩石的岩爆倾向。此外，还评估了钻孔数量和布置对岩爆倾向的影响。随着钻孔数量的增加，PESI 下降。当与加载方向的排列角度从90°变为27°再变为0°时，PESI先减小后增大；当与加载方向的排列角度为27°时，消除岩爆倾向和减弱峰值抗压强度的效率最佳。钻孔布置角度对岩爆倾向的影响大于钻孔数量。本文提供了一种定量评估 DPR 后岩石岩爆倾向的新方法，并阐明了 DPR 在降低岩爆概率方面的有效性。钻孔布置角度对岩爆倾向的影响大于钻孔数量。本文提供了一种定量评估 DPR 后岩石岩爆倾向的新方法，并阐明了 DPR 在降低岩爆概率方面的有效性。钻孔布置角度对岩爆倾向的影响大于钻孔数量。本文提供了一种定量评估 DPR 后岩石岩爆倾向的新方法，并阐明了 DPR 在降低岩爆概率方面的有效性。