What are the main calculation methods in seismic design of bridges? What are their characteristics?

The calculation methods in bridge seismic design mainly include static analysis, dynamic analysis and time-history analysis, and their characteristics are introduced as follows.

1. Static analysis method: It is a calculation method based on the principle of static balance, which is suitable for the seismic design of simple and rigid structures. This method is simple in calculation and does not need to consider factors such as vibration frequency and damping, but it cannot reflect factors such as dynamic response and nonlinear effect.

2. Dynamic analysis method: It is a calculation method based on structural dynamics theory, which can consider the vibration frequency, damping and other factors of the structure, and is suitable for the seismic design of moderately complex structures. This method can reflect the dynamic response and nonlinear effect of the structure, but it needs a lot of computing resources and professional knowledge.

3. Time-history analysis method: It is a calculation method based on seismic dynamics theory, which can consider the time-history characteristics of seismic waves and the nonlinear effect of structures, and is suitable for the seismic design of complex nonlinear structures. This method can reflect the dynamic response and nonlinear effect of the structure, but it needs a lot of computing resources and professional knowledge.

In a word, in the seismic design of bridges, different calculation methods have different characteristics and application scope, so it is necessary to choose the appropriate method for calculation and analysis according to the specific situation to improve the seismic capacity and safety of bridges.