板裂体组合条件下岩爆倾向性分析

Analysis of rockburst proneness under condition of combining spalling

针对已有突变理论仅对单块板裂岩体进行分析的局限性,提出将板裂化岩体作为整体进行研究,考虑了劈裂岩体间的水平应力,改进了突变理论模型在岩爆分析中的应用,并分别计算对比了单块岩板及板裂岩板组合在准静力及动力扰动两种条件下的岩爆倾向性。研究结果表明,准静力条件下单块岩板突变特征值?变化趋势平缓,而组合岩体由于等效抗弯刚度较大,?急剧增大;准静力条件下岩板组合的岩爆深度明显大于单块岩板时,岩爆深度达到0.76 m;随岩板厚度增加,突变特征值?逐渐增大,不再满足岩爆的充分条件,施加竖向扰动应力即可重新满足突变条件,所需外界扰动应力由几兆帕增大至几十兆帕。

In light of the limitation of analyzing the single spalling rock plate by the existing catastrophe theory, studying the spalling rock plates as a whole is put forward; the catastrophe theory applied to the rockburst analysis is improved, considering the horizontal stress between the splitting rock plates. Based on this, the rockburst proneness of single rock plate and combined spalling rock plates are calculated and compared respectively under the conditions of quasi-static and dynamic disturbance. The results show that: under the condition of quasi-static, the eigenvalue Δ of single rock plate changes gently while the eigenvalue Δ of combined spalling rock plates increases rapidly because of the large equivalent flexural rigidity; the rockburst depth of combined rock plates is obviously larger than that of single rock plate; and the depth reaches 0.76 m. As the thickness of rock plate increases, eigenvalue Δ grows up gradually and the sufficient condition of rockburst in no longer fulfilled. However, the catastrophe condition can be fulfilled again if external vertical disturbing stress is applied on the rock plates and the external stress needed increases from several MPa to tens of MPa.