| Compared to passive reinforcement technology, active reinforcement technology as one type of reinforcement can significantly improve the stress state and the carrying capacity of the bridge. Therefore, it will give full play to the mechanical properties of reinforcing material. A category of active reinforcement technology is the prestressing steel shear strengthening method of anchor bolt whose advantages not only contain those of active reinforcement, but also include anchorage reliability, low construction cost, simple operation and wide practicability. Therefore, the study of this new method of reinforcement is of great significance.At present, relevant literature on the strengthening method has not yet been found. However, when the concrete beam is strengthened, the unreasonable prestressed level will result in the poor effect of the reinforcement and even damage to the original structure of the bridge. To this end, it is necessary to carry out the research on the stress mechanism of the anchor plate shear strengthening in order to determine a reasonable prestressed level during the pre-reinforced concrete beam shear test study. In this paper, the mechanical behavior of shear strengthening is studied through two technical routes of experiment and numerical simulation of the concrete structures.In this paper, the main contents and results are presented as follows:(1)The active shear reinforcement test of member: the study contains simulating the real bridge reinforcement with the concrete component and taking the anchor bolt diameter and concrete strength as the key research objects, meanwhile, 27 prestressing steel shear strengthening tests are conducted. The deformation and failure modes of each component under different factors are observed, the relative load-displacement curve of the steel and concrete during the whole process is drawn and different concrete strength and bolt diameter on the influence of reinforcement are analyzed in the study.(2)Finite element analysis: using the finite element software ABAQUS to carry out the numerical analysis of the component reinforcement test. The numerical results are in agreement with the experimental results and the stress mechanism of the reinforcement is simulated truly. Through the comparison, some meaningful conclusions are drawn.(3)Theoretical analysis and conclusions: based on the experimental results and finite element analysis, the ultimate bearing capacity of reinforcement is analyzed theoretically. Combined with the recommended formula of different specifications and according to the test results under different failure modes, the modified formula of prestress standard value and design value are provided. It is practical and simple. Finally, the reinforcement design to a reinforced concrete T beam bridge is designed, using the modified formula to calculate the stress state after the reinforcement. And the calculation results show that the stress state of the inclined section is obviously improved. |
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