突水淹没矿井动水巷道截流阻水墙建造技术研究

在突水巷道中通过灌注骨料实现截流堵水的过程涉及多个力学演化阶段,实践中为了快速复矿需更重视堵水效果,阻水墙建造的关键技术问题研究很少受到关注。结合以往工程案例的堵水过程数据,分析了从骨料灌注到注浆截流的水力学模型,提出了阻水墙建造的关键技术参数设定方法,研究了阻水墙内部应力分布状态及破坏机理。研究表明:(1)阻水墙建造可分为4个阶段的水力学模型,即突水稳定阶段的管道流模型、骨料灌注阶段的管道流-低速渗流模型、骨料接顶阶段的高速渗流-低速渗流模型、注浆截流阶段的低速渗流模型;(2)动水中骨料堆积形态是水平和垂向两个维度共同生长的结果,堆积过程与流场存在动态平衡关系;(3)考虑压差、巷道阻力、堆积段阻力、浆液初凝时间4个要素,提出了堆积段长度估算模型,建立了不同灌注阶段巷顶流速的预测方法和骨料粒径选择方法;(4)注浆后阻水墙的最大剪应力发生在距来水方向较近的位置,相较堆积段全部长度,受力影响范围仅为其很小一部分;水压力越大,剪力和轴力越大,但分布状态、影响范围及峰值位置均不变;围岩与墙体弹性模量比越大,阻水体剪应力分布越集中,峰值剪应力越靠近来水方向;当剪应力最大位置首先达到抗剪强度后,剪应力将向下游产生塑性变形直至形成新的平衡状态,否则失稳破坏。

Study on construction technology of water blocking wall in hydrodynamic pathway of submerged mine due to water inrush

The process of blocking water by pouring aggregate into the water passage involves many mechanical evolution stages,people pay more attention to the water blocking effect than the project cost,which leads to the key technical problems of the construction process rarely involved.Based on the data of previous engineering cases,this paper analyzes the general construction process of water blocking wall,estab?lishes a hydraulic model to describe the process from aggregate accumulation to grouting closure,puts forward the calculation method of rel?evant parameters,and studies the internal stress distribution and failure mechanism of water retaining wall.The results show that:①The construction of water retaining wall can be divided into four stages of macro hydraulic model:the pipeline flow model in water inrush stage,the pipeline flow and low-speed seepage model in aggregate pouring stage,the high-speed seepage and low-speed seepage model in aggre?gate topping stage,and the low-speed seepage model in grouting closure stage.②The aggregate grows in horizontal and vertical direction in moving water and has an equilibrium relation with the flow field.③Considering the factors of pressure difference,wall resistance,accumula?tion section resistance and initial setting time of slurry,the estimation model of accumulation section length is established,and the predic?tion method of roadway top velocity at different stages and the selection method of aggregate particle size are proposed.④The maximumshear stress in the water blocking wall occurs near the direction of incoming water.Compared with the whole length of the wall,the affected range of stress is only a small part of them.The larger the water pressure is,the larger the shear force and axial force are,but the distribu?tion state,the range of influence and the peak position remain unchanged.The larger the ratio of elastic modulus of surrounding rock to wall,the more concentrated the distribution of shear stress,the closer the peak shear stress is to the direction of incoming water.When the maximum shear stress first reaches the shear strength,the shear stress will flow to the downstream until the equilibrium state is formed,oth?erwise the instability will be destroyed.