Seismic safety of high concrete face rockfill dams (CFRD) on thick layered deposit is crucial. This study develops a seismic performance assessment procedure for high CFRD on thick layered deposit considering multiple engineering demand parameters (EDPs), and evaluates the effectiveness of gravel column and berm reinforcement for a typical CFRD. Solid-fluid coupled seismic response analysis of high CFRD on thick layered deposit is conducted using an advanced elasto-plastic constitutive model for soil, revealing the unique seismic response of the system, including the buildup of excess pore pressure within the thick deposit. Based on the high-fidelity simulations, appropriate intensity measure (IM) and EDPs are identified, and corresponding damage states (DS) are determined. Fragility curves are then developed using multiple stripe analysis, so that the probability of damage under different input motion intensities can be quantified for different DS. Using the proposed procedure, the reinforcement effects of berms and gravel columns are evaluated. Results show that berms can contribute significantly to reducing the probability of damage for the system, while the effect of gravel columns is unsatisfactory due to the limited achievable installation depth compared to the thickness of the deposit and low replacement ratio.