**Abstract**

It is found that the failure of the structure conforming to the current seismic design code can only occur in the shear band of the tectonic earthquake, and with the increase in the amount of shear banding, the boundary conditions of the structure gradually deviate from the original design ones; therefore, the seismic insufficiency of structures therefore continues to increase. With the increase of the seismic insufficiency of the structure, the structure will appear more and more serious damage such as cracking, tilting and subsidence, and collapse. Based on the findings of this study, the author suggests that the main task of the seismic design of structures is to prevent the shear banding of tectonic earthquakes from extending to each element of the structure, rather than continuously increasing the level of vibration fortification of each structural element. Only in this way can it be ensured that the structures complying with the seismic design specifications will not be damaged such as cracks, tilting and subsidence, and collapse due to the deviation of the boundary conditions from the original design ones in shear banding.

**Keywords:** tectonic earthquake, shear banding, ground vibration, seismic conditions, boundary conditions, structural failures
