Abstract:In order to quantify the time-dependent seismic capacity deterioration law of existing RC frame structures in offshore environment, based on the chloride diffusion theory, a prediction model for the corrosion depth of reinforcement was firstly studied and established, and the numerical simulation method of existing RC frame structure is introduced. Then, the seismic capability of existing RC frame structures is characterized by PGA which represents the earthquake intensity of the structure can resist, and a method for quantifying the seismic capability of existing RC frame structures is proposed, which is based on the capability spectrum method. Based on this, the time-dependent deterioration law of seismic capacity of existing RC frame structures with different fortification levels is analyzed, and the corresponding prediction model is established. The results show that the seismic capacity quantification method established in this paper can directly quantify the earthquake intensity that the existing RC frame structures can bear under different failure limit states, and directly reflect its actual seismic capacity. With the increasing of service age, the seismic capacity of existing RC frame structures at different failure limit states degenerates linearly, and the degradation rate increases with the decrease of the level of fortification. With the improvement of the level of fortification, the onset time of seismic capacity degradation of existing RC frame structures keep advancing. The established time-dependent seismic capability prediction model can approximately characterize the law of seismic capability degradation of existing RC frame structures in offshore environment, but it needs to be implemented Example verification.