基于加卸载响应比理论的矿柱动力稳定性分析

利用有限差分程序FLAC建立连续和并排的两类非均质矿柱模型，对矿柱在动力载荷循环作用下的破坏过程进行全时程动力分析。将加卸载响应比(LURR)理论引入矿柱动力稳定性分析中，以施加的动力载荷对矿柱作用的周期性变化作为加载量，以矿柱特征点的位移变化和破坏单元的弹性应变能的演化规律作为响应参数，建立矿柱的加卸载响应比模型，确定矿柱在动力载荷作用期间的加卸载响应比时间序列。计算结果表明，矿柱整体上处于稳定状态和趋于失稳时，其加卸载响应比Y值表现出不同的特征，通过对Y值的分析对矿柱的稳定状态进行评价，预测是否临近峰值承载能力，表明在矿柱动力破裂过程数值模拟分析中引入加卸载响应比是矿柱破坏力学行为研究的一种方便而有效的方法。

Dynamic stability analysis of pillar based on loading-unloading response ratio theory

By the finite difference software package fast lagrangian analysis of continua(FLAC), a time-relied analysis is carried out to study failure process of heterogeneous serial and parallel rock pillars under cyclic dynamic loading. The theory of loading-unloading response ratio(LURR) is introduced to analyze dynamic stability of pillar. A LURR model of pillar is established by studying the laws of loading-unloading response ratio of pillar under dynamic loading. Through analyzing on the failure process of pillar, the loading-unloading parameter is determined as the periodical variation of dynamic loading. The displacement of pillar key point and elastic strain energy evolution regularities of failure elements are selected as loading-unloading response parameters respectively. Thereafter, the LURR time series of pillar is determined during the period of dynamic loading. It is found that the parameter Y of LURR can measure unstable degree of pillar. It can be applied to evaluate the stable state or predict the peak strength of pillar effectively. The results show that the loading-unloading response ratio theory is a very effective nonlinear dynamic analysis method in the dynamic stability prediction of underground pillar.