冲击载荷作用下吸能防冲支架与巷道围岩协调作用机理研究

The coordination of the surrounding rock of the support and the roadway is the core issue of the deformation control of the surrounding rock in the coal mining process, but the mechanism is not clear .The project adopts research methods such as experimental research, theoretical analysis and numerical simulation to establish the dynamic model of roadway surrounding rock-support system, analyze the law of variation of surrounding rock rigidity ,and study the impact rock vibration frequency of roadway surrounding rock ;to study the impact velocity of roadway surrounding rock under different impact energy; to establish the energy storage equation of the roadway surrounding rock elastic region. The storage energy of surrounding rock under the critical state of impact rock pressure is deduced. Study the stiffness of the stent under impact loading, the variation law of let-off velocity and energy absorption, and the natural frequency of the stent. The coordination equation between the support stiffness and the roadway surrounding rock stiffness is established to study the quantitative relationship between the support stiffness and the surrounding rock stiffness. The differential equations of dynamic response of the surrounding rock system of the support and the roadway are established, and the relationship between the allowable velocity of the support and the impact velocity of the surrounding rock is deduced. The energy equation of the surrounding rock system of the support and roadway is established, and the energy criterion for system instability is derived. Based on the coordination relationship between the stiffness, frequency, velocity, and energy of the surrounding rock of the support and roadway, an evaluation model based on the comprehensive index of the coordination between the support and surrounding rock is established to optimize the parameters of the energy-absorbing and impact-resistant support. The research results aim to perfect the parameter design theory of energy-absorbing and impact-resistant stents, which is of great significance to the prevention and control of rock pressure in roadways.

支架与巷道围岩协调作用是煤矿开采过程中围岩变形控制的核心问题，但机理不清。项目采用试验研究、理论分析和数值模拟等研究方法，建立巷道围岩-支护系统动力学模型，分析围岩刚度变化规律；研究巷道围岩冲击地压震动频率；研究不同冲击能量下巷道围岩冲击速度；建立巷道围岩弹性区贮存能量方程，推导冲击地压发生临界状态下的围岩贮存能量。研究支架在冲击载荷作用下的刚度、让位速度和能量吸收变化规律及支架固有频率。建立支护刚度与巷道围岩刚度协调方程，研究支架刚度与围岩刚度定量关系。建立支架与巷道围岩系统的动力响应微分方程，推导支架让位速度与围岩冲击速度关系。建立支架与巷道围岩系统能量方程，推导系统失稳的能量判据。基于支架与巷道围岩的刚度、频率、速度和能量的协调关系，建立以支架与围岩协调性综合指数为核心的评价模型，优化吸能防冲支架参数。研究成果旨在完善吸能防冲支架参数设计理论，对巷道冲击地压防治具有重要意义。

支架与巷道围岩协调作用是煤矿开采过程中围岩变形控制的核心问题，但机理不清。项目采用试验研究、理论分析和数值模拟等研究方法，研究了吸能防冲支架支护刚度与巷道围岩刚度协调关系、吸能防冲支架固有频率与巷道围岩震动频率协调关系、吸能防冲支架让位速度与巷道围岩冲击速度协调关系、吸能防冲支架吸收能量与巷道围岩释放冲击能量协调关系和吸能防冲支架与巷道围岩协调作用机理。主要得出以下重要结果，建立了巷道围岩-支护系统力学模型，推导出巷道断面形状为圆形时发生冲击地压的临界载荷公式，运用控制变量法研究得出降模量、内摩擦角、支护应力等因素为圆形巷道冲击地压临界载荷影响主要影响因素。得出了煤体压缩型冲击地压、顶板断裂型冲击地压和断层错动型冲击地压的大致频率范围分别为：25~35Hz，10~25Hz，1~18Hz。发明了一种矿用吸能防冲巷道支架频率检测装置。基于静力学平衡原理，推导得出了吸能防冲器扩径所需的轴向峰值力、吸收能量、平均压溃载荷、载荷波动系数等吸能防冲指标解析式。得出了不同冲击速度、不同冲击能量和不同材料下吸能防冲器的变形破坏规律。建立了吸能防冲支架与巷道围岩系统能量平衡方程，推导系统失稳的能量判据，得出冲击载荷作用下吸能防冲支架与围岩共同承载机理。发明了一种基于能量释放主体的冲击地压分类及判定方法，该方法将冲击地压微震监测数据分为震级、震动频率和震动持续时间三个释放能量特征，将冲击地压划分为煤体能量释放主体型冲击地压、顶底板断裂能量释放主体型冲击地压、断层带及围岩能量释放主体型冲击地压和顶底板断裂-煤体能量释放主体型冲击地压。设计研发了一种单元式吸能防冲巷道液压支架和新型柔性掩护支架。并对支架力学性能进行了数值分析。研究成果旨在完善吸能防冲支架参数设计理论，对巷道冲击地压防治具有重要意义。