Decision Method on Reasonable Design State of Self-anchored Suspension Bridge with Spatial Cables

According to the inherent requirements of self-anchored suspension bridge with spatial cables subjected to loads, the global flow to determine its reasonable design state is clarified. Proceeding from that the internal force state (especially bending moments) of the girder should be reasonable, the method to calculate the vertical component force of hanger is obtained. Based on both the fundamental analytical equations of spatial main cable shape-finding and the method to calculate the vertical component force of hanger, the specific procedure and approach to find the shape of spatial main cable and to calculate the parameters of hanger in the reasonable design state are developed with ensuring the convergence. According to the condition that the hanger in the reasonable design state only inclines in the cross direction, the recursive formula to calculate the line shape change stiffness of spatial cable are deduced. Thus, the highly efficient and precise method with clear route and definite conception is established, which is convenient for programming and deciding the reasonable design state of self-anchored suspension bridge with spatial cables. The efficiency and accuracy of the method in this paper has been well demonstrated by the case study on the Hangzhou Jiangdong Bridge.