Performance Analysis of Soft Roadway Surrounding Rock in Yushujing Coal Mine

There are soft rock layers in Yushujing coal mine, especially the roof-floor lithology of 11,501 working face shows the characteristics as soft rock, resulting in the drift floor-heave and failure of bolt in the process of coal extraction, which affects safe and efficient mining. To solve these problems, rock samples are taken from the roof and floor, and then the strength and deformation parameters of these samples are tested in the laboratory. Moreover, minerals components and microstructure of the rock samples are measured and observed through X-ray diffraction, scanning electron microscope and energy dispersive spectrometer techniques. The results show that the surrounding rock mainly consists of kaolinite, illite, smectite and chlorite. Among these minerals, the smectite's great hydroscopicity and high expansibility take the main factor for the deformation of surrounding rocks. Therefore, it is suggested that reinforcing the surrounding rock and reducing the deterioration of water might be effective ways to keep the stability of surrounding rock in soft rock roadway.