Geometry control simulation for long-span steel cable-stayed bridges based on geometrically nonlinear analysis

Abstract

The aim of implementing geometry control simulation to a cable-stayed bridge is to ensure that the specific designed geometric configuration will be satisfied after its construction. This paper presents a methodology, along with its software development, to simulate the different construction stages associated with cable stayed bridges and provide the erection configuration for each stage which ensures that the final designed geometric configuration is satisfied. To achieve this goal, a numerical simulation and control technique which considers geometric nonlinear effects is adopted. Multiple short truss elements are used to model the sag effect of long cables; additionally, the simulation of multiple tensioning stages associated with long cables is performed by successively adjusting the unstressed lengths of the cables. Beam–column and large displacement effects are considered using geometric nonlinear analysis based on the updated Lagrangian method. Three activation modes for new generated elements are considered during the geometry control analysis: tangent mode, parallel mode, and designated position mode. In order to demonstrate the capabilities of the proposed approach, a finite element computation software, denoted as BGCS, is developed and applied to the Sutong Bridge in order to simulate its geometric configuration throughout the construction process. The comparison of the simulation results with and without geometric nonlinearity shows that the effects of geometric nonlinearity cannot be neglected during the geometry control simulation associated with long-span steel cable-stayed bridges.