Spatial Stress Analysis And State Prediction Of V-shaped Pier PC Continuous Beam Bridge

As the development of society,the constructors are paying more attention on the combination of bridge modeling and city environment when they building bridges,and there is a higher demands on bridge aesthetics.V-shaped pier PC bridge is popular in city bridges not only for its graceful model and flexible curve but also for the structure could shorten the calculated span and improvement the stress.However,the stress distribution of V-shaped pier PC bridge is complex for its various curve in space,so it is necessary to analyze the level and distribution of bridge's spatial stress effect.At the same time,the bridge faces the deterioration of material properties and the augment of traffic volume when the bridge is completed,and the capacity of bridge will degrade as time goes by,so it is also necessary to predict the bridge's state,and provide technical maintenance advices.Using finite element software Abaqus building full bridge's FE model,analyzing the stress distribution rule and level in the stage of removing supports and the stage of completed bridge,the stress condition of main beam is similar with the beam whose two ends are fixed.The direction of third principle stress of V-shaped pier is similar with the direction of the norm stress,the V-shaped pier is considered as compressed members.The FE model's rationality is verified by the comparison of actual stress data from field tests and FE model's stress data,which have average errors between 1~1.5MPa.According to the distribution of bridge's internal forces,the key-sections are determined.According to the reliability method,the key points of materials' deterioration process in common atmosphere environment are determined,and the variable coefficient of materials' properties will increase in the process of materials' deterioration.Based on the materials' deterioration,the serviceability state predictions of main beam's crack resistance limit and V-shaped pier's crack width limit are engaged,the main beam's crack resistance reliability indexes decline faster when the pre-stressed steels begin to corrode and the reliability index of middle-cross-beam section firstly arrives to crack resistance limit,the V-shaped pier's crack width reliability indexes decline faster when the protective layer is cracked due to corrosion expansion and the section adjacent to the middle-cross-beam firstly arrives to crack width limit.According to the reliability method,the state predictions of main beam's bending capacity and shearing capacity and V-pier's eccentric compression capacity are engaged,every section's safety reliability index would decline as the materials' properties deteriorating.The reliability index of middle-cross-beam section firstly arrives to bending capacity limit and shearing capacity limit,and the section adjacent to the middle-cross-beam in V-shaped pier firstly arrives to eccentric compression limit.According to the results of serviceability and safety prediction,the maintenance and management suggestions of bridge could be provided by the key timing-points of bridge's states.