(1) Static theory. This theory does not consider the power characteristics of the building. Assuming that the structure is absolutely rigid, the building movement during the earthquake is absolutely consistent with the ground movement. The maximum acceleration of the building is equal to the maximum acceleration of the ground movement.

The maximum load that is received is equal to its product with the maximum acceleration of the ground. This theory is only suitable for low -rise buildings.

(2) Reaction spectrum theory. It considers both the dynamic characteristics of the ground during the earthquake and the dynamic characteristics of the structure itself. It is one of the most widely used earthquake design methods in the current engineering design. The reaction spectrum theory is based on the reaction of the single -quality point system under the actual earthquake to analyze the structure reaction. The maximum load value of the earthquake is usually only required for earthquakes, and its value is:

F = mamax = w (g) amax [3] formula, W is the mass point quality, called a horizontal earthquake influencing factor.

(3) Direct power analysis theory. When analyzing the flexible structure of large spans, due to the impact of non -linear factors, the calculation error of the reaction spectrum method is large. Direct power analysis theory can overcome the shortcomings of the theory of reaction spectrum. You can directly obtain the structural nodes in the process of the earthquake at all times of displacement, speed, and acceleration, so as to calculate the vertical

The internal force of the earthquake and the earthquake of components, these theories are called direct power analysis theory.

        The temperature should consider factors such as changes in temperature, solar radiation, and the use of thermal source. The temperature effect on the structure or component should be represented by changes in its temperature. When calculating the temperature effect of the structure or component, the linear thermal expansion coefficient of the material should be used. For large or large or large -scale, structural parts composed of different material components should be considered at the same time, and the temperature effects of different component materials should be considered at the same time and changes in the temperature field of the entire structure.