水砂突涌试验系统研制与应用

Development and application of test system for water-sand inrush

为研究水砂在采动覆岩裂隙中运移和突涌特征,研制了水砂突涌试验系统。以孔径为5 mm的水砂通道为例,通过设置不同的水压力,揭示水砂流量和含水砂层底部水压变化特征。在含水砂层水压接近临界水头压力时,水砂突涌会呈现失稳—运移—沉积—稳定的现象;若含水层水压超过临界水头压力,随着水压值的增加,水砂稳定流量呈升高趋势,二者为线性正相关。水砂通道开启瞬间,含水层内水压会出现明显的波动降低,水砂流量呈现先升高后平稳的趋势,随着水砂流量的平稳,水压也逐渐趋于稳定,但较初始设计压力仍有一定降低;在含水砂层底部,随着监测点距水砂通道距离的增加,水压呈逐渐升高趋势。试验结果表明该试验系统稳定可靠,研究方法及结果对进一步认识采煤工作面涌水溃砂灾害的形成机制具有指导和借鉴意义。

In order to study the water-sand migration and inrush across overburden fissures, a test system is developed. The water-sand passageway with 5mm pore size is taken as an example, the change of water-sand flow and water pressure at the bottom of water-bearing sand layer are researched. When the water pressure in water-bearing sand layer is close to the critical water pressure, water-sand inrush presents instability-migration-deposition-stabilization. When the water pressure in water-bearing sand layer exceeds the critical water pressure, the water-sand stationary flow trends to increase with the increase of water pressure and the two are linear positive correlation. At the moment of opening the water-sand passageway, the water pressure in water-bearing sand layer shows a wavelike decrease, the water-sand flow shows increased and then maintains stable. The water pressure tends to be stable gradually with the stability of water-sand flow, which is also less than the initial design water pressure. At the bottom of water-bearing sand layer, with the increase of distance between the monitoring point and water-sand passageway, the water pressure shows is gradually increasing. Test results show that the system is stable and reliable,which have great significance for studying the formation mechanism of water and sand inrush across overburden fissures further.