Frictional Resistance between Cable and Saddle Equipped with Friction Plate

To increase the frictional resistance between a cable and saddle, a method using a horizontal friction plate is efficient. However, there is no precedent for its use on long suspension bridges. An experimental investigation is conducted using a test cable and saddle with a friction plate. The frictional behaviors under normal and seismic loads are considered. Even under such a violent variation of load resulting from an earthquake, the cable is no more liable to slip than under a normal load. Based on the experimental findings, an analytical model of the frictional mechanism is developed, and as an example, the model is used to analyze a suspension bridge. As a result, the mechanism is made clear, and a formula for the design overall frictional coefficient of the saddle with a friction plate and a seismic safety factor are proposed. They are adopted for the design of the Rainbow Bridge in Tokyo.