Study On Bolt Supporting And Mechanism Of Distortion And Destruction In Soft Rock Roadway Under High Stress And Swelling Conditions

The supporting of deep high tectonic stress soft rock roadway has been a difficult technical problem of the Baijiao Coal Mine for really a long time. If there is a high level of tectonic stress while the roadway in the highlands of stress environment. It will bring a great deal of difficulties to the Coal Mine roadway supporting, and in this condition, the technical issues of swelling soft rock roadway supporting remain expectation to be solved. Therefore, study on the soft rock support on the conditions of high stress and swelling is of important significance in both theoretical and practical, and is the key to ensure the safe exploitation of deep mine.From the concept of soft rock, this article discusses the characteristic and mechanics attribute, and classification of the soft rock. It obtains that the roadway floor is the expansive clay stone and the mudstone by examining the physical mechanics properties and the mineral components at the spots, promulgates the mainly reason that why the floor-heaving was caused easily on the roadway floor in the Baijiao Coal Mine, and then determines the Mining Area entry belongs to the high-stressed and swelling soft rock roadway.By the observation and investigation at spots, the paper systematically analyzes the rule of distortion and the characteristic of destruction of three kinds of typical soft rock roadways (working section, floor laneway, up-downhill tunnel).The working section is easily to rib spalling and floor heaving affected by mining and floor soft rock. Influenced by not only mining and soft rock, but horizontal tectonic stress causes the floor laneway and the up-downhill tunnel convergence of two ribs of tunnel and heaving of floor easily. It obtains the characteristics of distortion and destruction of roadway under different conditions of supporting by numerical calculation, and reveals the mechanism of the distortion and `destruction of roadway. The destruction areas of roadway mainly are tensile stress area and shear stress area. The roof can be better controlled, but ribs of roadway and floor can not be effective controlled. The convergences are large between the roof-floor and two ribs of roadway, and floor heave is obvious. The key of supporting is to strengthen the control of ribs and wall corners, and do well in connect measures between ribs and floor.In the situation of researching stress of roadway roof, it brings forward the concept of the arch of self-stabling limit equilibrium, and gives the calculation formula of balanced arch theoretical. At the same time, it also analyzes relations of distortion and destruction between the ribs and the roof, as well as the influence factors and controlling measures of the floor heaving, and puts forward the principle of supporting"govern roof goes against govern the ribs first, govern ribs to govern the floor first, the shoulder feet are the key and control through the whole".Finally, through the numerical calculation and theoretical analysis, this article proposes separately the schemes of bolt and cable strengthen supporting at the working section and floor laneway and up-downhill tunnel, which have carried on the project practice, and it will provide beneficial references for the similar roadway supports.