Ultimate Load-Bearing Capacity Study On Anchorage Zone In A Long Span PC Box Girder

To increase the tensioning force in a single tendon, various new types of special anchorage devices are adopted in the bridge engineering. The stress distributions of the related anchorage zones are complicated. The safety and the crack resistance of the anchorage zone which exists due to the usage of large tonnage ancho device, are the critical part of the structural design. Because there is no reliable method to calculate the strength and crack resistance of the anchorage zone for this type of device, careful theoretical analysis and physical test must be carried out.A study of the ultimate load-bearing capacity of anchorage zone in a long span PC box girder was undertaken in the background of Tiger Jump Gate Bridge project of Guang-zhu Rail line.First, a 3D linear finite element model of the PC box girder had been established, then to determine the stress concentration zone of the anchorage zone through analysising of the model results, establishing the submodel, the feasibility of model can be approved through comparative analysising of the results of Box-girder model and submodel.Second, Hear finite element analysis and nonlinear finite element analysis of the submodel were both carried out. ABAQUS's concrete damage plasticity model was used during the simulation of the whole loading process of the submodel, the variation of stress distribution of design load in the concrete was investigated.the ultimate load-bearing capacity and damage process of anchorage zone can be determined.Third, some parameters were studied by using elasto-plastic finite element method.the affect of the orthogonal reinforcement steel, the pitch and radius of the spiral reinforcement on the ultimate load-bearing capacity of submodel, and the coupling affect of them on the ultimate load-bearing capacity of submodel.