The surrounding rock of swelling soft rock roadway has high clay mineral content, strong expansibility after encountering water, low strength and poor cementation. The roadway is prone to large deformation under the influence of complex geostress. Combined with the support change of the development roadway of 2# coal in Hongqingliang mine, through geological survey, field observation and indoor test, the failure mechanism of the traditional support method of “anchor bolt + anchor cable + anchor mesh + shotcrete” was revealed by the adjustment of the surrounding rock stress after the excavation and support of the adjacent chambers. The research results show that the surrounding rock stress will cross the adjacent chambers and form a concentrated area near the weakly cemented roadway, and the maximum stress increase ratio of surrounding rock within the stress concentration range will reach 50%. The farther the chambers are from the weakly cemented roadway, the smaller the range of the surrounding rock stress concentration area. When the distance exceeds about 12 times the average height of the chambers, the surrounding rock stress concentration tends to disappear. Based on the fully enclosed combined support method of the "U-shaped steel sheds closure roof and sides + filling flexible material behind the sheds + laying reinforcement mesh and concrete in floor + strengthening key parts", the construction process flow applicable to the working condition of swelling soft rock roadway is formulated.

No abstract

After excavation of the weakly cemented roadway adjacent to the chambers, deformation characteristics such as roof subsidence, roadway extrusion, and floor heave appear, showing the characteristics of large deformation of surrounding rock, long deformation duration, and serious damage, which are not conducive to guaranteeing safety mining. Based on the technical means of the rock mechanical property test, mineral composition analysis, in situ stress test, and surrounding rock deformation monitoring of 2# coal roadway in Hongqingliang coal mine, a numerical simulation study on the influence of surrounding rock stress on adjacent chamber groups was carried out. The physical and mechanical properties of the weakly cemented rock were obtained, the stress distribution law of the 2# coal roadway was mastered, the deformation characteristics of the surrounding rock of the weakly cemented roadway were obtained, and the deformation and failure mechanism of the weakly cemented roadway adjacent to the chambers were revealed. The relationship between the regional stress increment of the chambers and the failure range of the surrounding rock of the roadway is revealed, establishing a mechanical model of allowable deformation + stress release + controlled form with U-shaped steel as the main structure. The roadway support countermeasures were given and applied in engineering practice.