摘要
利用自制的水砂流运移及突涌模型进行试验,模拟了采动覆岩体裂缝通道中水砂流的运移与突出过程,研究了煤层开采水砂混合流运移特性。根据煤层采动引起覆岩破坏形成的垮落带、导水裂缝带通道情况,将水砂混合流运移通道侧壁面分为平直光滑无充填的、粗糙起伏无充填的及有充填软弱泥质物质的3类,并针对这几种形态进行了模型试验。试验以0.05 MPa和0.1 MPa水压力条件下的不同通道裂缝宽度、不同倾角、不同通道侧壁形态为例,揭示了孔隙水压力在裂缝通道中不同位置的变化特征。突水涌砂在采空区是瞬间发生的,在裂缝通道内,根据孔隙水压力的变化,将水砂混合流运移过程分为相互关联的3个阶段:上升阶段、稳定阶段及突出阶段;总结了水砂混合流突出阶段的水压力变化曲线的特征,划分出了3种水砂突出类型:直泻式突出型、跳跃式突出型和缓坡式突出型。由此,探索了水砂混合流运移特征及动力机制。
The startup, migration and inrush processes of the mixed water and sand flows in the overburden fractured channel are studied by designing and manufacturing the test model, which can be used to simulate the migration and inrush of mixed flows. The characteristics of the mixed water and sand flows in various types of fractured channels are investigated. Three stages of the mixed-flow migration and three types of the mixed water and sand inrush are brought forward. Based on the caving zone and the water flowing fractured zone channel of overburden by mining, the fracture channel sidewalls of the mixed flows are divided into three types： straight and smooth wall without filling, rough and stepped wall without filling and soft mud substance with filling. The numerical tests on the three types are carried out. The variation characteristics of water pressure at different positions of the fractured channel are revealed considering the variations of widths, inclination angles and sidewall types of the fractured channel under the water pressure of 0.05 MPa and 0.1 MPa. The results show that the water and sand inrush instantly occur in the mined area. Based on the characteristics of water pressure variations, the migration process of the mixed flows in the fractured channel is divided into three interdependent stages： increasing stage, stability stage and outburst stage. According to the characteristics of the water pressure variations during the mixed-flow inrush, the mixed-flow outburst is divided into three basic types： direct outburst type, saltatory outburst type and gentle slope outburst type. Therefore, the migration characteristics and dynamic mechanism of the mixed flows are explored.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2012年第4期686-692,共7页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金青年科学基金项目(40802076)
中国博士后基金面上资助项目
江苏省高校优势学科建设工程资助项目
关键词
薄基岩
厚松散层
水砂流
运移特征
thin bedrock
thick unconsolidated formation
mixed water and sand flow
migration characteristic
