Experimental Research on Seismic Performance of Bottom Joints in Prefabricated Steel-Reinforced Concrete Outer Walls of Underground Metro Stations

A prefabricated steel-reinforced concrete structure for column-free underground metro stations was proposed. The seismic performance of the bottom joints of outer walls was studied by quasi-static loading tests on three 1/3-scale specimens， including one specimen with concrete solid sidewalls， one specimen with concrete composite sidewalls， and one cast-in-place specimen. The results showed that the bottom joints of the prefabricated steel-reinforced concrete outer walls with solid sidewall and composite sidewall configurations all exhibited excellent structural integrity， with their bearing capacities close to that of the cast-in-place specimen. The ductility coefficients of the specimens with solid concrete sidewalls and composite concrete sidewalls were 3.1 and 3.0， respectively， which were 7.0% and 3.4% higher than those of the corresponding cast-in-place specimen.The energy dissipation capacity and stiffness degradation characteristics of the two prefabricated steel-reinforced concrete specimens were similar to those of the cast-in-place specimen.