Abstract: The selfsupporting tower foundation includes two types: ground foundation and frame foundation. The seismic analysis of frame foundation is more complex, which is a difficult point in the seismic design. For the frame foundation, decoupled analysis is usually adopted for the frame supported tower and the supporting frame in the conventional method, and seismic analysis is carried out separately for the tower and frame foundation. The calculation model can't fully reflect the vibration characteristics of the combined structure of the tower and the frame, which is quite different from the actual engineering. In this paper, the overall combined structure model of tower and frame is established, and the distribution of mass and stiffness of the frame and tower along the height direction is taken into consideration. After comparative analysis, the seismic effect based on the overall model is less than that of the conventional simplified method, which is in line with the actual engineering. This can optimize the seismic design of frame and tower effectively.

Key words: tower frame foundation, mode-superposition response spectrum method, decoupled analysis, seismic horizontal influence coefficient, natural vibration period