This study proposes and investigates a modular assembled steel–ultra-high-performance concrete (UHPC) composite cable support bridge consisting of upper prefabricated UHPC ducts and a steel truss underneath. Finite element (FE) analysis is conducted to investigate the mechanical performance of the medium-span (L = 36 m) cable support bridge under service-loading conditions. The FE results indicate that under combined action of vertical and horizontal loads, the tensile damage in the UHPC ducts reaches approximately 10%, mainly concentrated near the end-support sections. The peak stress in the steel truss is far below its yield strength. The peak vertical displacement of the bridge is approximately L/225, below the allowable limit of L/150, and the peak horizontal displacement is negligible. A parametric analysis is performed for web sections in the midspan and end of the cable support bridge. Results show that the peak stress located at the lower chord increases with larger midspan web section. The increase in the midspan web section triggered a stress redistribution in the end webs and, consequently, a rise in the peak stress under the same load case; the peak vertical displacement decreases while the horizontal displacement exhibits marginal change. Appropriately scaling down the end diagonal web sections optimizes the material distribution, achieving a reduction in self-weight with negligible impact on the overall structural performance.
Li et al. (2026) studied this question.