岩溶隧道充填型隐伏溶洞涌突水持续时间特征试验研究

Experimental study on water inrush duration characteristics of filling-typed concealed karst cave in karst tunnel

为研究岩溶隧道充填型隐伏溶洞涌突水持续时间特征,通过自主设计试验装置开展了不同介质上覆水头高度、介质沉积高度、介质类型和介质颗粒级配特征等条件的涌突水模拟试验,研究结果表明:(1)隐伏溶洞涌突水演化过程可分为四种模式,即渗-涌-突水(砂)模式、涌-突水(砂)模式、突水(砂)模式、渗-突水(砂)模式;(2)颗粒级配和介质种类对渗水(砂)阶段持续时间影响明显,细砂、中砂颗粒含量与持续时间的关系可用多项式函数表示,泥沙型介质持续时间大于砂砾型;(3)介质沉积高度和介质类型对涌水(砂)阶段持续时间影响明显,砂砾型和泥沙型介质沉积高度与涌水(砂)持续时间呈正相关,泥沙型介质持续时间小于砂砾型;(4)介质颗粒级配和沉积高度对突水(砂)阶段持续时间影响明显,细砂颗粒含量与持续时间的关系可用多项式函数表示,砂砾型介质沉积高度与持续时间呈先增大后减小的关系。研究结果对于隐伏溶洞涌突水灾害预警与防治措施具有一定的理论指导价值。

In order to study the duration characteristics of the filling-typed concealed karst cave in karst tunnel, the simulative experiments on the water inrushes for the conditions of overlying water head height, sediment height, type and particle gradation of different media are carried out with the relevant self-designed experiment device. The study results show that(1) the evolution process of the water inrush in concealed karst cave can be divided into four modes, i.e. seepage-water inrush-water(sand)burst, water inrush-water(sand) burst, water(sand) burst, seepage-water(sand) burst;(2) the influences from the particle gradation and the medium type on the duration of the water(sand) seepage stage are significant, while the relationship between the particle contents and durations of fine sand and medium sand can be expressed by the relevant polynomial functions, for which the duration of the sediment-typed medium is larger than that of the sandy gravel one;(3) the influences from the deposition height and type of medium on the duration of the water(sand) inrush stage are significant, while the deposition height and type of medium of both the sandy gravel-typed medium and the sediment-typed medium are positively correlated to the duration of the water(sand) inrush, for which the duration of the sediment-typed medium is less than that of the sandy gravel-typed one;(4) the influences from the medium particle gradation and deposition height on the duration of water(sand) burst are significant, while the relationship between the fine sand particle content and the duration can be expressed by the relevant polynomial functions, for which the relationship between the deposition height of the sandy gravel-typed medium and the duration exhibits a trend of increasing at first and then decreasing. The study results have certain theoretical referential values for the early warning and prevention measures for the disaster of water inrush in concealed karst cave.