Cable-stayed suspension hybrid bridges (CSSHBs) integrate the advantages of cable-stayed bridges and suspension bridges into a highly rigid structure. However, due to their hybrid nature, the static performance of CSSHBs is highly sensitive to various factors, presenting significant challenges for parameter analysis and scheme comparison during design. This study presents a new live load effects analysis strategy for the hybrid bridge with varied structural parameters. The methodology expands the application scenarios of variable parameter influence line (IL) analysis. It solves structural live load responses based on the area of influence lines with the same sign and constructs a “parameter variation-structural response” diagram. Simultaneously, it extracts critical live load cases, enabling designers to adjust parameters during the conceptual design phase based on calculation results from a limited number of load cases. The 690 m Tuwan Bridge is used as the benchmark model for the case study. The study first investigates the characteristics of its influence lines, followed by parametric studies. Results indicate that when the main girder stiffness is increased by a factor of 100, the deflection at the mid-span section and the cable force amplitude of the side hanger are reduced by 53% and 81%, respectively. And increasing the sag-to-span ratio proves effective in mitigating live load effects. Finally, the structural static responses under three critical load cases are analyzed to comprehensively validate the proposed analytical strategy.
Meng et al. (Wed,) studied this question.