Restoring force model for steel reinforced concrete columns with high steel ratio

Key points on the load-displacement skeleton curves of steel reinforced concrete (SRC) composite cantilever columns are established based on the experimental results in the literature. Influencing parameters such as the ratio of encased steel, the transverse reinforcement characteristic value, the size of the cross-section, etc. are considered in the study. A degrading trilinear restoring force model applicable to SRC columns with an encased steel ratio of 10-20% is suggested. The main results show that the influencing parameters have different effects on the values of key points. The proposed restoring force model, which considers various influencing parameters, can predict the test results more accurately and can be applied to the non-linear dynamic analysis of structures with such SRC column types.