Application of quick group search optimizer with passive congregation algorithm in cable force optimization of completed bridge of cable-stayed bridge

This study introduces the Quick Group Search Optimizer with Passive Congregation (QGSOPC) coupled with the influence-matrix method to optimize cable forces in a completed 1 070 m, five-span, twin-tower cable-stayed bridge. Compared with the original design, QGSOPC reduces maximum tower-top displacement by 83.8% (84.1 → 13.6 mm), girder deflection by 41.9% (236.7 → 137.5 mm) and peak bending moment by 11% (118 078 → 105 120 kN·m), while lowering the composite objective function by 40.7%. A comparative analysis using GSO confirms the enhanced performance of the proposed algorithm. The results demonstrate that QGSOPC offers a practical, efficient tool for achieving the "straight-tower & level-beam" completion state of long-span cable-stayed bridges.