Theoretical Research On The Ductility Of Reinforced Concrete Bridge Piers And Evaluating Seismic Capability

This article introduced the concept of ductility, ductility index and earthquake force calculation method of national norms. In view of the lack of existing norms calculate typical continuous bridge to determine the ratio of seismic demand and capacity within the reasonable limits, with the corresponding reinforcement of a reasonable rate, and ensure the ductility of piers. Then we will put forward some suggestions on the ductility design of piers of typical continuous bridge.It described the development of seismic design, advantages and disadvantages of the response spectrum and time-analysis method. It introduced the method to calculate seismic demand moment of typical continuous bridge, constitutive relationship model for cover concrete, core concrete and Reinforced Bar to calculate the bending resistance ability of pier. Elastic-plastic fiber unit was introduced by checking the bridge earthquake response Methods.Calculate the ductility of the typical continuous bridge, including 3spans with span length of 30 miters, 5spans with span length of 30 miters, 3spans with span length of 20 miters and 5spans with span length of 20 miters. To calculate the demand moment of piers in medium earthquake and the bending resistance ability we use the response spectrum method and the procedure which called xtract. Then calculate the ratio of seismic demand and capacity. Adjust the reinforcement ratio with reasonable rate. For the piers that meet the needs of earthquake seismic, aggregate the reasonable axial compression ratio, the ratio of seismic demand and capacity and the scope of safety factor which on the basis of the typical design of the proposed bridge piers ductility.The piers which meet the needs of the bending requirement are examined the shear-resistant strength. The longitudinal reinforcement ratio has been determined on the vertical section of plastic hinge. The results show that: such piers which meet the needs of the bending requirement of typical continuous bridge in Eight Seismic Degree Area also meet the requirements of shear strength.