A methodology for nonuniform slip analysis and evaluation of cable strands within saddle

The safety of suspension bridges requires a secure connection between the main cable and saddle. However, the traditional approach of physically homogenizing the main cable fails to consider its discrete contact and nonuniform slip characteristics within the saddle, exacerbating the cable-saddle anti-slip problem that particularly perplexes the application of multi-tower suspension bridges. In this study, a nonuniform slip analysis model of main cable incorporating with vertical friction plates is first constructed on basis of the proved Strand Element method. Large-scale model tests are then conducted to reveal the slip behavior of cable strands and confirm the slip model. Finally, a typical multi-tower suspension bridge, encountered unprecedented anti-slip challenges due to the use of a rigid middle tower, is taken as an example for an extended case study. The results demonstrate that the slip of the cable strands within the saddle is nonuniform, and the proposed model can effectively predict the entire slip process and offer key indicators. Adding vertical or horizontal friction plates can significantly enhance the ultimate anti-slip capacity of the main cable, but the former presents better overall anti-slip performance. The number and position of vertical friction plates have noticeable effects on the anti-slip performance, and such parameters can be flexibly optimized based on the proposed slip model and matching evaluation criterion, tailored to the specific requirements of actual bridges. The methodology eventually developed can guide the anti-slip design and evaluation of the cable-saddle system, which will greatly promote the application of multi-tower suspension bridges. •A novel slip model is constructed considering the nonuniformity of main cable and the participation of friction plates.•Large-scale model tests are performed to reveal the slip behavior of cable strands and confirm the proposed model.•A typical multi-tower suspension bridge is specially considered for an extended case study.•The influence of key parameters is clarified, and a matching graded anti-slip evaluation criterion is provided.