基于塑性区扩展的煤层巷道变形破坏影响因素分析

Influencing factors analysis of deformation and failure of coal seam roadway based on plastic zone expansion

为了分析煤层巷道赋存条件对巷道围岩变形破坏的影响,选取煤层厚度、顶底板厚度、顶底板岩性、煤层瓦斯压力作为分析因素,利用FLAC^(3D)数值模拟软件进行正交试验,得到不同赋存条件下煤层巷道围岩塑性区情况,分析了各因素对塑性区扩展的影响程度。研究表明:影响煤层巷道围岩变形破坏程度的因素从高到低依次为煤层厚度、煤层瓦斯压力、底板厚度、底板岩性、顶板厚度、顶板岩性,其中煤层厚度和煤层瓦斯压力对围岩变形破坏有显著影响并呈正相关;当顶板厚度30 m、煤层厚度15 m、底板厚度15 m、顶板岩性为泥岩、底板岩性为粉砂岩、煤层瓦斯压力为0.7 MPa时,煤层巷道围岩塑性区最大半径最大,巷道最易发生变形破坏。

In order to analyze the influence of coal seam roadway occurrence conditions on the deformation and destruction of roadway surrounding rock,the coal seam thickness,roof and floor thickness,roof and floor lithology,and coal seam gas pressure are selected as the analysis factors,and the orthogonal test is carried out using FLAC^(3D) numerical simulation software to obtain the plastic zone of coal seam roadway surrounding rock under dfferent occurrence conditions,and the influence degree of each factor on the expansion of plastic zone is analyzed.The research shows that the factors affecting the deformation and damage degree of surrounding rock of coal seam roadway are in order of coal seam thickness,coal seam gas pressure,floor thickness,floor lithology,roof thickness and roof lithology from high to low.Among them,the thickness of coal seam and coal seam gas pressure have a significant impact on the deformation and damage of surrounding rock and are positively correlated.When the roof thickness is 30 m,the coal seam thickness is 15 m,the floor thickness is 15 m,the roof lithology is mudstone,the floor lithology is siltstone,and the coal seam gas pressure is O.7 MPa,the maximum radius of the surrounding rock plastic zone of the coal seam roadway is the largest,and the roadway is most prone to deformation and damage.