Design and Research of Lattice Steel Bracing in RC Column Replacement Reinforcement

To investigate the mechanical properties of lattice steel bracing in the process of displacement reinforcement of reinforced concrete (RC) columns, this study conducts design calculations and construction monitoring analyses of lattice steel bracing in practical engineering contexts. Subsequently, an axial compression test is performed to analyze the ultimate bearing stability, failure states, and weak links of the steel bracing with a shaped steel sheath at the base. Additionally, five finite element models of steel bracing with identical material sizes but varying heights are established to examine their ultimate bearing capacities and vertical deformations. The results indicate that the deformation of the lattice steel bracing in the actual project is small, and the working conditions are favorable. Notably, the maximum bearing capacity obtained through construction monitoring is 148.032 kN, which is very consistent with the calculation results. In the axial compression test, the primary mode of failure observed is shear failure of the tensile bolt within the lattice steel bracing specimen. Furthermore, the finite element numerical simulation results reveal that the ultimate bearing capacity of models with varying heights is between 2410 and 2420 kN under the vertical displacement control; however, vertical deformation progressively increases with the height of the steel bracing under the same load.