深部块系岩体超低摩擦现象的机理分析
Mechanism of anomalously low friction phenomenon in deep block rock mass
-
摘要: 不规则超低摩擦现象是深部块系岩体典型动力学特征现象之一,集中反映了深部块系岩体非协调、非连续的动力学特性。基于俄罗斯Kurlenya M V院士的深部岩体超低摩擦实验建立了深部块系岩体一维动力模型,得出了工作块体水平位移的解析表达式。研究结果表明,一维动力模型理论计算结果与实验数据吻合较好,进一步揭示了深部岩体不规则超低摩擦现象产生的力学条件为分别作用于块系和工作块体上的竖向和水平冲击的时间间隔满足倍数为2的规范序列,指出超低摩擦现象产生机理在于强动载作用下块体间法向力重分布和动摩擦系数不断变化的共同作用,同时说明超低摩擦现象出现的离散周期和低频低速变位摆型波频谱具有密切联系。Abstract: The anomalously low friction phenomenon is one of the typical dynamic phenomena in the deep block rock mass,reflecting the inconsistent and inconsecutive dynamic characteristics of deep block rock mass.Based on the anomalously low friction test carried by Russian academician Kurlenya M V,a one-dimensional dynamic model was established,and the analytical solution of transverse displacement of working block was obtained.It was demonstrated that the analytical results based on the one-dimensional dynamic model agreed well with the experimental data.The geo-mechanical condition for the occurrence of the anomalously low friction phenomenon lied in the canonical coordination of delay intervals between the vertical and horizontal pulse impact on the block system and the working block respectively,and its formation mechanism rested on the redistribution of vertical force and variation of dynamic friction factors between blocks under the powerful impact,and the discrete periods of anomalously low friction phenomenon were closely related with the spectrums of low-frequency low-speed reversal pendulum-type wave.