Study on classification and support of surrounding rock of mining roadway in extremely close coal seams

Abstract

In order to explore the stability category and support mode of surrounding rock of mining roadway in extremely close coal seams, the stability category of surrounding rock is determined by comprehensive evaluation with mathematical method.Firstly, the mathematical model is established by using the method of fuzzy comprehensive evaluation, and factors such as the nature of surrounding rock and stress environment are selected as the classification index of surrounding rock.Then, fuzzy comprehensive discriminant matrix, index weight and membership degree of surrounding rock are solved.Then, the classification of surrounding rock stability is verified by the method of grey correlation degree analysis.Finally, the corresponding roadway support mode is put forward.The results show that degrees of membership of mining roadway in extremely close coal seams to Ⅰ-Ⅴ type surrounding rocks are 0.184 6, 0.211 7, 0.186 6, 0.177 6 and 0.239 4, respectively.The degree of membership of V type surrounding rock is the largest, which is consistent with the verification results.Surrounding rock belongs to V type extremely unstable surrounding rock.In addition, the roof is broken and roadway pressure is small due to extremely close mining.Then U-shaped steel beam shed support is proposed.The observation of rock pressure shows that the effect of roadway support is remarkable.

Keywords

• extremely close coal seam
• surrounding rock classification
• fuzzy comprehensive evaluation
• grey correlation analysis
• roadway support