Experimental and numerical investigation of the lateral impact resistance performance of reinforced concrete-filled corrugated steel tubular column

Corrugated steel tube filled with concrete offers an effective solution to corrosion issues commonly faced by marine and coastal structures such as offshore bridges, platforms, and wind turbine towers. It boasts excellent mechanical properties and construction efficiency, making it highly suitable for harsh marine environments. During their service life, these structures may endure lateral impacts from vessels, debris, or severe weather conditions, which can cause significant damage to columns. This study investigated the behavior of reinforced concrete-filled corrugated steel tubular (RCFCST) columns subjected to lateral impacts using drop hammer tests, with comparisons drawn against traditional reinforced concrete (RC) columns. At an impact height of 0.5 m, RC columns exhibited concrete spalling and cracks approximately 6 mm wide, while RCFCST columns showed no visible cracking and demonstrated a 47% reduction in residual displacement, indicating superior impact resistance. A finite element model was developed to further explore the lateral impact performance of these columns. Numerical simulations examined the effects of various parameters, including longitudinal and stirrup reinforcement ratios, wall thickness, wave height, wave spacing, and impact height. Results revealed that increasing the longitudinal reinforcement ratio from 1.2% to 5.1% enhanced the plateau force by 78.7%, decreased the peak displacement by 44.52%, and reduced the residual displacement by 78.77%. Similarly, increasing wall thickness from 2 mm to 4 mm elevated the peak impact force by 49% and the plateau force by 35%, while peak and residual displacements decreased by 36% and 23%, respectively. Conversely, increasing the wave height from 20 mm to 48 mm lowered the plateau force by 50% and increased peak and residual displacements by 47%. The stirrup reinforcement ratio and wave spacing exerted minimal influence, each causing less than a 10% variation in key response metrics.