Control on construction of the main cable for Wujiang suspension crossing of Zhongwei-Guiyang Pipeline

The main cable for suspension crossing of Wujiang Pipeline is characterized by low gravity stiffness and high flexibility. It is hard to be adjusted since its shape is greatly influenced by the positioning of anchorage cable sleeve, prebias of cable saddle, ambient temperature and span. In order to precisely adjust the suspended cable shape, based on the unstressed state theory, this paper establishes the precise iterative algorithm for non-stress length and shape of cable strand, which comprehensively considers the factors like temperature and span and can control and adjust the elevation between cable strand and free cables quickly and effectively. Parameter variation method is adopted to analyze the possible impacts of temperature and span on the suspended cable shape and cable tension, so as to observe the stability after the adjustment of cable strand and verify the changes of cable shape with temperature and span. The construction observation result shows that both relative and absolute elevation deviations of the cable strand in upstream and downstream of this project meet the requirements of technical specification. This iterative algorithm adapts well in the construction of main cable for suspension crossing of Wujiang Pipeline. With advantages of fast calculation and high monitoring efficiency, this algorithm is an effective and reliable analysis method for building and adjusting cable strand for suspension crossing of pipelines.