Theoretical And Experimental Study On Deformation And Failure Of Surrounding Rock In Deep Roadway

In the process of deep tunnel construction,the deformation and destruction of the surrounding rock often cause great loss of property and personnel,and influence the construction process.The study of the deformation and destruction of the deep surrounding rock will play a certain reference for the prevention of the deep roadway disaster.After the excavation of the deep roadway,the surrounding rock will be deformed and destroyed under the two stress of its formation.At the same time,the surrounding rock is driven by the dynamic action of blasting and mechanical disturbance,and the dynamic deformation and failure of the surrounding rock of the deep roadway will be induced.But at present,the study of deformation and failure after excavation is still not deep enough.Therefore,this paper takes the deformation and failure of the surrounding rock of the deep roadway as the research object,and combines the theoretical analysis and the test means to analyze the deformation and failure of the deep surrounding rock under the static and dynamic conditions after the excavation.The research work and achievements of this paper are as follows:(1)In this paper,the mechanism of failure and deformation of surrounding rock under static and dynamic conditions is studied by means of theoretical analysis,and a model box test can be designed to better observe the deformation and failure of surrounding rock subjected to the dynamic disturbance of blasting under different ground stress.(2)Combining with the catastrophe theory,the failure mechanism of the surrounding rock under static action is studied.The static failure of the surrounding rock needs its static force to be more than a certain value,otherwise the surrounding rock will not destroy immediately after the tunnel is excavated,but it will creep with time and produce larger deformation during the creep process,and this final deformation amount follows the surrounding rock.The static and elastic modulus increases with the increase of the static and elastic modulus.(3)Dynamic action will induce large deformation and failure of surrounding rock and dynamic deformation and failure under dynamic action.The greater the loading speed of the power,the greater the dynamic bearing capacity of the surrounding rock,and the greater the dynamic failure of the dynamic force.On the contrary,the larger the static force after the excavation of the tunnel,the deformation and failure of the surrounding rock can occur under the smaller dynamic load.(4)In the model box test,the surrounding rock is classified and pressurized,and several times of blasting are carried out after each level is pressurized and stabilized.Influenced by the blasting disturbance,the displacement of the surrounding rock under the ground stress is obviously greater than that of the surrounding rock which is affectedBy the blasting,and the displacement on one side of the multi distribution point is obviously smaller than that on one side of the single point.It shows that the timely support can effectively control the deformation of the surrounding rock after the excavation of the tunnel.After the excavation of the deep surrounding rock,under high ground stress,the top of the cave is pulled,which is prone to fracture and deformation.The surrounding rock of the cave has large deformation and the crack is pulled and falling,the wall of the cave is pressed and fractured.This is a deformation and failure mode of the complete brittle rock.In the process of tunnel stress,the horizontal strain of the roof is greater than the vertical strain.The vertical strain of the tunnel wall is larger than the horizontal strain,so the deformation and failure of the surrounding rock is the result of the strain of the surrounding rock surrounding the tunnel.