Researching Of Anchoring Mechanism And Design Method On Anchorage Section Of Pressure Diffusion Cable

As pressure diffusion cable researching and developing successfully, it has been increasingly used in water conservancy, transportation and other fields, and it played a huge role on the soft rock and soil bearing capacity of the lower permanent reinforcement. But the theory fall behind the engineering practice and the design calculation method is not yet ripe, there are many issues need further study and discussion. It is great significance for improving geotechnical engineering prestressed anchorage theory and practical application if studying its mechanism of action and rational design methods as well as guiding the rationalization of construction of cable.Taking the part of Er-guang Expressway Project within Guangdong province (from Huaiji to Sanshui) as the research background. indoor model test, theory analysis and numerical analysis are used to research the mechanism of pressure diffusion cable. Distribution of shear stress between injecting cement paste and hole wall are gained by numerical analysis. The design method of pressure diffusion cable anchorage section is given by the results.First of all, stress mechanism, especially the progress of are reviewed through experimental, numerical analysis and theoretical. The paper introduce pressure diffusion cable including structure and mechanical characteristics, the difference between ordinary pull-type cable, the advantages as well as application range in details.Secondly, combining with model experiment and numerical simulation, the anchorage mechanism of pressure diffusion cable are analyzed. The results showed that:(1) If the pressure diffusion cable are received same prestress, with the rock strength Increases, shear stress between injecting cement paste and hole wall also increased and the effective length of anchorage section decreased. The same rule to the axial force of grouting. (2) shear stress between injecting cement paste and hole wall of pressure diffusion cable in the bearing plate there is an initial stress, the maximum pressure plate at a distance of about 0.05m place; the shear stress between injecting cement paste and hole wall of pressure diffusion cable distribution curve in two forms.Finally, combining with prestressed cable design method in home and abroad as well as the results of laboratory and numerical simulation, two curves form of shear stress between injecting cement paste and hole wall of pressure diffusion cable are proposed on the condition of different prestress and bond force. At the same time, basing on the two curves form, the formula of effective length and ultimate strength are given.