垮落带下金属网和双抗网防溃砂机理试验研究

Experimental investigation on the mechanism of metal and double-antibody net for water and sand inrush prevention under caving zone

为探究垮落带下金属网和双抗网防溃砂的力学与水动力学机理,文章将模型试验与渗透试验结合,设计50cm×50cm×20cm的模型,支撑金属网和双抗网进行受压试验;对四种粒径砂颗粒进行渗透对比试验。结果发现:金属网和双抗网都能承受较大荷载而不破坏;铺设双抗网对于阻止砂颗粒潜蚀效果明显,阻隔了砂溃入井下的通道;铺设双抗网后,渗透系数降低,小颗粒砂降低更明显,底部比中部铺设渗透系数降低值及降低率大;中部和底部同时铺渗透系数降低值及渗透系数降低比更大。颗粒越小,降低率越大;双抗网和金属网的铺设能使垮落带形成相对稳定的顶板结构,顶板完整性得到增强。

To investigate the mechanics and hydrodynamics mechanism of the metal and double-antibody net for water and sand inrush prevention under caving zone, model test and penetration test were combined in this paper. The steel model （50cm ×50cm× 20cm） was designed to support the metal and double-antibody net to conduct pressurized test. The comparison penetration tests of four particle size sand were conducted. The results show that the metal and double-antibody net can withstand great load without damage; the double-antibody net plays a great role to prevent the sand from subsurface erosion and block the sand collapsing inrush into the underground space. The permeability of four particles sands decreases after laying the double-antibody net, especially the small particle is more obvious, the decrease of permeability and the ratio of decrease when laying the double-antibody net at the bottom is greater than laying in the middle. Permeability decrease when laying the double-antibody net in the middle and at the bottom is the greatest in these tests, the decrease of permeability is greater as the particle is smaller. Stability of the caving zone is enhanced with the metal and double- antibody net, and the integrity of the roof is improved.