Characteristics Of Bearing Structure And Mechanism For The Deep Soft Rock Roadway

On the basis of detailed analysis the predecessors’achievements, the deformation mechanism of deep soft rock roadway were analyzed in detail by using laboratory experiments, theory analysis, numerical simulation and practice method, master the double bearing structure characteristics of deep soft rock roadway and put forward control method.Combined the geological conditions, analysis of the water ratio influence on the stress field and bearing structure of surrounding rock in deep soft roadway, the result shows that the bearing structure at a certain range obviously and presents the double bearing structural characteristics. Simulate the different buried depth of soft rock roadway by using numerical simulation method FLAC3D, and analyze the deformation mechanism and characteristics of the double bearing structure, the deformation and strain of which surrounding rock in the range of surface to3m in deep soft roadway inner bearing structure are serious, the displacement and its ratio are big. Deep rock that range3m to12m belongs to outer bearing structure, it could control the deformation of the surrounding rock effectually and reduce the deformation shift into depths.Through mechanics analysis, deduce the displacement formulas of elastic area and bearing structure and the outer bearing structure’boundary. Define the out boundary of the outer bearing structure is the radius of plastic zone2.5times. analyze the characteristics of the bearing structure, roadway surrounding rock stability is closely related to the plastic zone radius, as the each value of the bearing structure thickness is smaller, the stability of roadway is better, and these could be the guide to the stability control of surrounding rock.Industrial test results show that the theoretical analysis of the bearing structure of deep soft rock tunnel excavation is reasonable. The supporting design can satisfy the goal to reduce the displacement deformation of surrounding rock of roadway and effectively improve the stability of the roadway.