刚–柔–刚支护防治冲击地压理论解析及实验研究

 冲击波在巷道围岩–多孔金属材料–钢支护构成的刚–柔–刚(R-F-R)支护结构的传递过程可简化为一维应力波在结构中传播问题，通过对R-F-R支护结构防治冲击地压理论分析，得到岩块冲击多孔金属材料–钢支护结构时多孔金属材料对冲击波压力的衰减情况以及多孔金属材料厚度、密度对冲击波压力衰减的影响。采用落锤冲击实验方法，对3种类型支护结构进行冲击实验研究，分析冲击波在R-F-R支护结构中的传播和衰减规律，实验结果表明，R-F-R支护结构具有良好的缓冲和吸能作用。理论计算与冲击实验结果对比可知，计算结果表明钢板冲击R-F-R支护结构时作用在钢支架表面的冲击波压力为钢板直接冲击钢支架时的30.7%，钢板冲击R-F-R支护结构时可吸收能量值约为总能量的94.8%；冲击实验结果表明，作用在R-F-R结构钢支架表面的冲击波压力为钢板直接冲击钢支架时的50%左右，钢板冲击R-F-R支护结构时吸收能量值约为总能量的70%以上。

THEORETICAL ANALYSIS AND EXPERIMENTAL RESEARCH ON ROCKBURST PREVENTION MECHANISM OF RIGID-FLEXIBLE-RIGID SUPPORTING STRUCTURE

The transfer process of shock waves in supporting structure of rigid-flexible-rigid(R-F-R) can be simplified as one-dimensional stress wave propagation in the structure.The law of shock wave pressure attenuation affected by porous metal materials and the shock wave pressure decay influenced by thickness and density of porous metal materials were obtained by the impact theory analysis of prevent blunt mechanism of R-F-R supporting structure.The impact energy-absorption ability of three types of supporting structures was studied by drop hammer impact test.At the same time,the spread and attenuation process of impact wave in R-F-R supporting structure was analyzed.The calculation results show that the shock wave pressure applied to the surface of R-F-R supporting structure is 30.7% of the shock wave pressure applied to the surface of steel bracket,and the R-F-R supporting structure absorbs energy about 94.8% of the total energy.The experimental results also show that the shock wave pressure applied to the surface of R-F-R supporting structure is 50% of the shock wave pressure direct applied to steel bracket,the R-F-R supporting structure can absorb more than 70% of the total energy.