Suspension and Tension Rope Applications on Bridges

Wire ropes are capable of responding to various purposes such as bridge structures with a design principle suitable for the carrier system that can be used economically, systems used for lift and crane-type lifting-transport purposes or the need for transportation in the mining area.

Ropes are structurally composed of multiple bundles. The configuration of the bundles, their types and different geometrical properties within themselves constitute various types of ropes.

Ropes are divided into two as steel core and fiber core according to the material type in their centers. Apart from the material types, the ropes are also differentiated according to the formation of the central cores. The central cores of the ropes can be in the form of bundles or ropes. If the ropes with the central core in the form of bundles differ from the bundles surrounding the core, they are called independent core wire ropes. If the central core consists of rope, the rope is called bundled ropes.

Simple bundles are formed by winding a center wire and 6 outer wires surrounding it at a certain angle of rotation. The outer wires surrounding these bundles have a helical form and complete a certain number of turns (number of steps) along the bundle length depending on the helix angle. The length that the wires take along the beam axis in one turn while being wound is called the pitch length.

Wire ropes have high bearing capacity. Apart from the effects of wear and corrosion that occur during operation, there is no loss of strength due to the effect of fatigue and moisture. Their safety is quite high due to the fact that the loads are dispersed to many wires in the rope.

The most important properties of wire ropes are their low stiffness in bending and twisting. Due to these features, it keeps the force demands on the cables low in the transfer of internal forces, the formation of moments in cable sections at very low levels compared to tensile forces and their ability to meet high tensile forces play an effective role in the use of ropes in very wide spans.

In this study, wire rope and bundle types used in bridge structures were investigated under the effect of axial force and bending. The bundle and rope types discussed in the study reflect the characteristic features of the bundles and ropes that make up the suspension, inclined suspension ropes and main cables used in bridges.

The ropes that make up the bridge cables have great thicknesses. For this reason, the sections used in the study have been reduced in certain proportions but in a way that shows the same characteristic behavior.