考虑双模量特性的块系岩体摆型波传播规律研究

A study on the propagation law of pendulum-type wave in block-rock mass considering bimodulus characteristics

摆型波现象是深部岩体工程中的一种独特的岩体动力学现象,极易引发冲击地压等深部岩体工程灾害。针对深部块系岩体的非均匀性特征,基于岩体等级块系构造理论,利用改进的中心差分法,研究具有双模量特性的块系岩体摆型波的传播规律,分析模量比对摆型波传播规律的影响。研究表明:模量比对块体正向位移幅值影响不大,而对负向位移幅值具有较大影响;块体位移最大值在中前区衰减较慢,而在末端快速衰减,不同模量比的块体位移在末端有收敛的趋势;模量比对速度响应的振幅无明显影响,但能使速度响应周期增大;随模量比的减小,加速度响应出现摆型波的“成簇”现象,得到了试验现象的证明。最后,基于摆型波理论提出了预防冲击地压灾害的两点建议:①增强巷道围岩整体性;②改进传统巷道支护方式,考虑支护结构的抗冲击性能和抗疲劳性能;研究具有双模量特性的块系岩体摆型波对研究复杂的不均匀的深部岩体动力学性质、保证工程安全具有重要意义。

The pendulum-type wave is a unique rock mass dynamic phenomenon in deep rock mass engineering,which is easy to cause deep rock engineering disasters of rockburst.According to the characteristics of heterogeneity of deep block-rock mass,the law of pendulum-type wave propagation was studied in block rock mass with bimodulus characteristics based on the block-hierarchical theory of deep rock mass and the improved central difference method.The influence of the modulus ratio on the law of pendulum-type wave propagation was analyzed.The research shows that the modulus ratio has little effect on the amplitude of the positive displacement of the block,but has a greater influence on the amplitude of the negative displacement.The maximum value of block displacement decays slowly in the middle and front area,while it decays rapidly at the end,and the block displacement with different modulus ratio tends to converge at the end.The modulus ratio has no obvious effect on the amplitude of velocity response,but it can increase the period of velocity response.With the decrease of the modulus ratio,the acceleration response appears as a phenomenon of“clustering”of the pendulum-type wave,which was proved by experiment.Finally,based on the theory of pendulum wave,two suggestions for preventing rockburst disasters were proposed:one is to enhance the integrity of the surrounding rock of the roadway;the other is to improve the traditional roadway support method,considering anti-impact performance and fatigue resistance of the supporting structure.Pendulum-type wave in block rock mass with bimodulus characteristics is of great significance to the study of dynamic properties of complex and heterogeneous deep rock mass and ensure engineering safety.