Clamp laying-out for free cables of pipeline suspension bridge

For the main cable of suspension bridge, its free shape is significantly different from its bridging shape. To ensure that the bridging shape after construction accords with the design to the maximum extent, the accuracy of the suspender position is crucial. Therefore, the laying-out of cable clamps onto the main free cable is a top priority, since the clamps decide the accuracy. In this paper, the exact solution of the unstressed length of catenary is adopted. The function correspondence of the suspender position between the free state and the bridged state is analyzed carefully, and the iterative calculation method for the clamp lay-outing at coordinate horizontal distance is proposed. Taking the pipeline suspension bridge as an example, the sensibility and impacts of some factors on the accuracy of clamp laying-out are discussed. Such factors include data of clamp laying-out at coordinate horizontal distance, temperature, span and laying-out process. The study results provide valuable guidance for laying-out of the cable clamps. Actual operations show that the laying-out accuracy can be controlled within 1 cm, fully meeting the error scope. This case study proves the practicability of the iterative calculation method of the coordinate horizontal distance for cable clamp, the laying-out method of the cable clamp at coordinate horizontal distance, and the temperature and span correcting method in the clamp laying-out for free cables of pipeline suspension bridge.