Nonlinear Stress-Free-State Forward Analysis Method of Long-Span Cable-Stayed Bridges Constructed in Stages

Structural analysis and construction control of staged-construction processes are major subjects in the context modern long-span bridges. Although forward backward methods able to simulate situations, their main disadvantage is that they usually apply stage superposition principle. In actual process, due changes made plan, process needs be adjusted at any time, it difficult implement complete accordance with established plan. As a result, existing simulation method based on incremental structural each has poor adaptability such adjustments. this study, considering strong geometric nonlinear behavior cable-stayed bridge geometrically mechanical equations bar system structure were derived. The minimum potential energy theorem was used by introducing concept stress-free-state variable elements. equation reflects influence change variables elements completion state structure. From geometrical condition equilibrium holds, stress-free installation closing section planar beam element obtained. A new for been proposed, which called analysis. This can directly obtain intermediate without performing stage-by-stage demolition calculations, causing internal force deformation reach design target state. realize multi-process parallel operation construction, solves problem automatic filtering temporary loads. To illustrate application method, analyzed.