OPTIMIZATION FOR CABLE-FORCE OF EXTRADOSED CABLE-STAYED BRIDGES BASED ON MINIMAL COST PRINCIPLE

According to the characteristic of extradosed cable-stayed bridges, an optimization method was put forward to minimize the cost of cables and tendons. The method follows the idea that the feasible stress range of a beam under a dead load is firstly determined by design strength subtracting the stress due to the live load and other actions. The method is aimed at minimizing the total cost of cables and tendons, realized by introducing the influence matrix of cable and tendon forces in a line with the modulating principle. The function is materialized with ANSYS APDL and the optimization theory is examined on a real bridge. The results show that the total optimized cost of cables and tendons is only 47.9% of that of the original design.