Abstract: The design of joints of concretefilled steel tubular (CFST) columnreinforced concrete (RC) beam with visibleconcealed twincorbel in the metro station excavated by cutandcover topdown method in Hohhot, Inner Mongolia is of great significance. As a result, a new type of CFST joint with visibleconcealed twincorbel is put forward, which is analyzed by simulation software ABAQUS and model test. Meanwhile, analysis is made on the key design parameters of the joint. The results show that: (1) The effective weld length between the annular corbel rib plate and the steel pipe wall is the main parameter affecting the shear resistance of the node, and by adjusting which the mechanical properties of the joint can be significantly improved. (2) In order to ensure the effective transfer of shear force, 8% of the diameter of steel tube column should be taken as the appropriate value. (3) When the shear force at the beam column joint is large, the visibleconcealed twincorbel can be used, which has high bearing capacity and excellent mechanical properties as well as a wide range of engineering application prospects.

Key words: metro station, cutandcover topdown excavation method, visibleconcealed twincorbel, ABAQUS, shearing capacity