Numerical study on cable-saddle frictional resistance of multispan suspension bridges

For multispan suspension bridges, the frictional resistance between main cable and saddle is vital to counterpoise unbalanced cable tension between adjacent main spans. The calculation for frictional resistance is essential for the bridge design. In this study, a numerical method for frictional resistance between main cable and saddle is developed. The proposed method is validated against large-scale saddle model tests, and then used to analyze the frictional resistance in a multispan suspension bridge. The method is used to investigate the main components of total frictional resistance, the effects of vertical friction plates, and the frictional resistance distribution along the longitudinal direction of saddle. The results indicate that the frictional resistance at the bottom and side surfaces between main cable and saddle are the main components of total frictional resistance. The distribution of frictional resistance along the longitudinal direction of saddle increases from one end to the other end of saddle. To add vertical friction plates is an effective way to increase the frictional resistance. The proposed numerical method provides an effective and feasible tool for evaluating the frictional resistance.