Construction Control On Structure System Transformation Of Self-anchored Suspension Bridge With Spatial Cables

Spatial cables self-anchored suspension bridge has improved in both visual effects and structural stress compared with the ordinary suspension bridge. But also face a construction process of system transformation. In the progress, the displacement will be occurred to the main cable in vertical, longitudinal and transverse. Also, the torque caused by the tilt derrick to the main cable and the nonlinear factors will make the construction process complicated and hard to control. This paper is based on Yang-mingtan bridge and researched the progress of system transformation. Main research and results are as follows.1、This paper researched the three construction methods in the progress of system transformation. Tensioning sequence, tension hierarchiesin and three calculation methods in derrick tensioning method are stated. In addition, several nonlinear factors were studied in the progress of system transformation and three solution methods of the nonlinear equation were introduced.2、Finite element model is established and the error was analyzed through the two control means of unstressed length and derrick tensioning stress. When the unstressed length was adopted, the random error and system error were well controlled in the range of±20mm and±10mm. When the derrick tensioning stress was adopted, the two errors were±5%and±2%. Both control effects are excellent.3、Through assembling a simulation analysis of construction process, main cable displacement and the changing rule of the boom force were got in derrick tensioning process. And the reasonable control method was got in different construction process. Not only the efficiency of construction is improved but also ensured the control accuracy.4、Unstressed length manner was adopted in the derrick tensioning progress of Yang-mingtan bridge. Formal analysis and unstressed control method were combined to control the construction process. And the system transformation was completed. The deviation between actual bridge state and target state is small and the measured derrick force is evenly. And the ideal derrick force error is within3%, the control effect is excellent.