水力冲孔孔洞受压变形特征模拟研究

Simulation on Deformation Characteristics of Hydraulic Punching Holes under Pressure

为研究水力冲孔成孔的形态及受围压变形规律,进一步阐明水射流冲孔破煤卸压增透机理,利用有限元数值模拟软件,建立水力冲孔孔洞形态模型,探究孔洞受压变形规律及出煤量与孔洞变形的关系。研究结果表明:高压水射流成孔后,在孔洞内部上下两侧区域出现最大主应力,孔洞变形主要集中在孔洞顶部中间位置且形成凹陷区域;冲孔出煤量与孔洞顶部最大主位移量呈正相关;需合理设计高压水射流参数,确定最佳成孔深度,防止孔洞塌陷、煤体结构失稳,从而避免顶底板灾害事故发生。

In order to study the shape of hydraulic punching hole and the deformation law under confining pressure,and further clarify the mechanism of pressure relief and permeability enhancement of water jet punching.The finite element numerical simulation software was used to establish the shape model of hydraulic punching hole,and the deformation law of hole under pressure and the relationship between coal yield and hole deformation were explored.The results show that the maximum principal stress appears in the upper and lower sides of the hole after high-pressure water jet drilling,and the deformation of the hole is mainly concentrated in the middle area of the top of the hole and forms a concave area.The coal output is positively correlated with the maximum principal displacement at the top of the hole.It is necessary to reasonably design the parameters of high-pressure water jet and determine the optimal hole forming depth to prevent the roof and floor disasters caused by hole collapse and coal structure instability.