Deformation characteristics and stability control of soft coal-rock mining roadway in thin coal seam

In order to overcome the problems of large deformation and difficult control of surrounding rock in semi coal-rock roadway,the deformation mechanism and stability control were studied based on the thin coal seam in Baise Are-a. Firstly,on the basis of data collection and data sorting,the engineering geological characteristics of thin coal seam mining roadway were analyzed. It was found that the geological structure of thin coal seam mining roadway is generally complex and the integrity of surrounding rock is poor. During the whole process curve of surrounding rock deformation, the engineering behaviors and deformation characteristics of surrounding rock were analyzed in the initial roadway ex-cavation influence stage,roadway excavation stability stage and working face recovery stage. Then,according to the col-lected rock samples and the self-made coal-rock combination samples,the mechanical strength experiments of coal-rock combination with different point load strengths and different height ratios were carried out respectively. The exper-iments show that the rock with low mechanical strength,and the failure law of coal and rock mass is different,showing inhomogeneous deformation. Finally,the slip mechanism of semi coal-rock roadway was analyzed,and the constitutive equations of interlayer slip and the instability of surrounding rock were derived. The control principle and supporting points of weak semi coal-rock roadway were expounded according to the extrusion bearing of cable and the shear action of bolt. The overall support technology with anchor,net,cable and beam was proposed,which is mainly composed of roof pre-stressed long cable and high rigidity truss cable. The support test proves that the proposed support technology has a good application effect in No. 2406 roadway in Dongsun coal mine,and the deformation of surrounding rock can be restrained within a controllable range.