Research Of Mechanism And Stability On The Soil Nailed Retaining Structure

Soil Nailing in fact is a support technology with the joint effect of soil reinforcement, soil nailing and the surface .Because of its convenience and fast, power of applicability, economic and reliablity, it is widely used in the supporting projects of various slopes, foundations.However, in theory, there is still a lack of correct understanding on the soil nailing job mechanism and stability.In this paper, using quasi-cohesion theory, on the basis of research of soil nailing supported structure with the vertical slope and horizontal soil nailing by Qin Siqing, the job mechanism of the structure is studied with inclination angle of slope and soil nailing.A new concept of rupture angle is proposed,and soil nailing internal force transmission formula is derived from the shear-lag theory.On the basis of the results of previous studies, combined with the monitoring results, a theory of structure's crack - sliding double linear damage model is proposed and its stability formula is derived.Through a project with various conditions of monitored soil nails force and displacement,the influence of the various conditions to the force transmission and the displacement is analysed; the transitive law of force is studied; and the transitive formula of force is verified by the coincidence between the tested value and the caculation by the transitive formula in this paper.In addition, through the analysis of the max soil nailing tension, the potential failure surface of the structure of soil nailing is determined, which is coincident with the crack - sliding double linear damage model of the structure of soil nailing proposed in the paper, and the angle between the sliding surface and horizontal surface with the rupture angle.Finally, the structure model of soil nailing is set up by the use of the finite difference method FLAC software, and get a numerical simulation to the engineering examples. And further, the soil nailing mechanism and stability is analysed with the coincident result to the test values and the theoretical calculations.In this paper, the study of soil nailing mechanism and stability has very good reference value to the design and construction of traditional soil nailing.