Effect of Initial Cable Tension on Cable-Stayed Bridge Performance and a New Construction Method

Abstract

The tension forces of cables in cable-stayed bridges during their construction and operation may differ from initial conditions, which could affect the amount and distribution of internal forces on other parts of the bridge. If some bridge elements are loaded to their yield limits, alternating plasticity and incremental collapse could occur under moving and repeated loading. This study investigated the effect of the initial tension force on the stiffness, strength, shakedown limit load, and alternating plasticity of cable-stayed bridges, which has not been studied so far. Two case study bridge models with cables having different initial forces were tested using nonlinear static analysis under gravitational force and nonlinear dynamic analysis under transient moving loads. The results showed that changes in the initial cable forces did not change the initial stiffness, ultimate strength, shakedown limit, alternating plasticity, or bridge reliability. These results were theoretically validated using plastic analysis theorems. This paper presents a new construction method for cable-stayed bridges based on the finding that adjusting the cable tension to the design value is not necessary during construction and operation. This method eliminates the need for tension adjustment and ensures that the final geometric shape of the bridge matches the expected profile. The proposed method offers a simpler and more efficient approach to constructing cable-stayed bridges without compromising the safety and durability of the structure.

Keywords

• cable-stayed bridge
• shakedown analysis
• alternating plasticity
• incremental collapse
• construction analysis
• nonlinear analysis