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冲击地压载荷下O型棚支架动力响应规律研究

Study on dynamic response law of O-shaped support under rockburst loading

  • 摘要: 掌握冲击载荷下O型棚支架的动力响应规律是设计冲击地压巷道O型棚支架支护参数的理论基础。通过现场支护承载力变化规律,获得影响冲击载荷对支护作用的主要影响因素;建立冲击载荷下O型棚支架的动力学方程,获得冲击载荷作用下巷道O型棚支架的动力响应。研究表明:冲击能产生的冲击载荷可造成O型棚支架承载力突增并产生振动;冲击能在煤岩介质中传递时衰减迅速,当冲击源距巷道达到一定值时,冲击载荷对支护的作用力基本可以忽略不计;当冲击能增大到一定值后,冲击载荷对支护的作用力快速增长;O型棚支架刚度对支架动力响应产生较大影响,支架刚度越高,支架振动频率越小,因此合理的支架刚度有利于提高支架的抗冲击性能;随着冲击载荷作用于O型棚支架时间的增加,O型棚支架的弯曲变形逐渐减小。由此可见,冲击源距巷道支架距离、巷道围岩介质属性、O型棚支架刚度、冲击载荷持续作用时间等因素均对O型棚支架动力响应产生较大影响。以此为依据,利用改变壁厚填充增加冲击地压载荷作用时间、增加支护密度提高支护刚度与强度等方式对O型棚支架支护参数进行优化,现场实践表明优化后的O型棚支架可抵抗106J能量的冲击地压,支护破坏情况明显改善,抗冲击性能显著增强。

     

    Abstract: Astering the dynamic response law of O-shaped support under impact load is the theoretical basis for designing support parameters of O-shaped suport in rock burst roadway. According to the change law of on-site support bearing capacity, the main factors affecting the impact load on the support are obtained. The impact energy generated by the impact ground pressure is partially transmitted to the O-support support bracket of the roadway in the form of impact stress waves, which causes deformation of the roadway support. Mastering the dynamic response of the roadway support under impact loading is the key to improving the impact resistance of the O-shaped support. The dynamic equation of the O-shaped support under the impact load is established, and the dynamic response of the roadway O-shaped support under the impact load is obtained. Studies have shown that by analyzing the characteristics of the impact ground load, it is found that the impact energy is attenuated rapidly when it is transmitted in the coal-rock medium. When the impact energy increases to a certain value, the force of impact load on the support increases rapidly.When the impact source reaches a certain value from the roadway, the impact load on the support is basically negligible; when the impact energy is increased to After a certain value, the impact of the impact load on the support increases rapidly. The dynamic equation of the O-shaped support under impact load is established, and the dynamic response of the O-shaped support under the impact load is obtained. The results show that the impact load will cause the O-shaped support to increase suddenly and generate vibration; The interaction between the O-shaped support and the surrounding rock under the action: the dynamic response of the O-shaped support under the impact load is affected by the surrounding rock coal and rock mass and the stiffness of the surrounding rock. The stronger the ability to displace and slow the internal force of the bracket, the better the impact resistance; the stiffness of the bracket is proportional to the dynamic response of the bracket. The higher the strength, the smaller the vibration frequency of the bracket. Therefore, the reasonable bracket stiffness is beneficial to improve the impact resistance of the bracket. The stiffness of the O-shaped supports has a greater impact on the dynamic response of the support. The higher the stiffness of the support, the lower the vibration frequency of the support. Therefore, a reasonable stiffness of the support is beneficial to improve the impact resistance of the support. As the impact load acts on the O-shaped support, the time increases, the bending deformation of the O-shaped support frame gradually decreases. It can be seen that factors such as the distance between the impact source and the roadway support, the properties of the surrounding rock medium of the roadway, the stiffness of the O-shaped support, and the duration of the impact load have a greater impact on the dynamic response of the O-shaped support. It was found that the bending deformation of the O-shaped support bracket gradually decreased with the increase of the impact load time. The research results are used to guide the optimization design of the O-shaped support parameters of a mine, and the dynamic response characteristics and regularity of the O-shaped support after the optimization of the supporting parameters are verified by the on-site support effect, so as to study the energy-absorbing and anti-shock O-shaped support in the future. Scientifically design the O-shaped support parameters to provide the basis.Based on this, the support parameters of the O-shaped support are optimized by changing the wall thickness and filling to increase the impact load time, increasing the supporting density and improving the rigidity and strength of the O-shaped support. Field practice shows that the optimized O-shaped support can withstand the impact ground pressure of 106 J energy, the damage of the support is obviously improved, and the impact resistance is significantly enhanced.

     

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