Slip Behavior of Cable Against Saddle in Suspension Bridges

Abstract

In long suspension bridges with a small span ratio of side to center, cable slip load against the saddle is large and it is important to grasp its frictional resistance in the design. An experimental investigation is done using a test device that simulates the state in a real bridge. As a result, it is made clear that the frictional coefficient in the case of a saddle surface coated with inorganic zinc‐rich primer is 0.31, and that zinc‐metallized is 0.60. And slip behavior of cable is clear as follows: (1) The slip starts at a relatively small value of the frictional coefficient, but even after slip starts, the frictional resistance grows, and after a maximum value is reached, the decline is gradual; (2) a fractional slip continues even after the slip load is held constant, and it takes a considerably long time for the slip to cease; and (3) the bolt‐tightening force for increasing frictional resistance declines considerably after tightening the bolt.