Decreasing Displacements of Prestressed Suspension Bridge

Abstract

A suspension bridge is the most suitable type for a long-span bridge due to rational use of structural materials. Increased deformability, which is conditioned by the appearance of the elastic and kinematic displacements, is the major disadvantage of suspension bridges. The problem of increased kinematic displacements under the action of symmetrical and non-symmetrical load can be solved by the prestressing. A prestressed suspension bridge with span of 200 m was considered as an object of investigations. The cable truss with the cross web was considered as the main load carrying structure of prestressed suspension bridges and was compared with the single cable. The considered prestressed suspension bridge was investigated by the FEM program ANSYS 12 and by the small scale physical model. Rational, from the point of view of minimal vertical kinematic displacements, main load-carrying structure of prestressed suspension bridge was developed. The obtained results shows, that usage of cable truss with the cross web as the main load carrying structures of prestressed suspension bridge in comparison with the single cable, reduces vertical displacements upwards by 63.1%, downwards by 1.8% and total displacements by 29.6% under the action of worth situated load.

Simplified Method of Determination of Natural-Vibration Frequencies of Prestressed Suspension Bridge

“…The electronic dynamometer work principle is based on changes of electrical bridge resistance. The precision of measurements for the electronic dynamometer is 2.5 N [26]. To connect the deck with the load bearing cable, adjustable suspensions are used, that allow levelling of the deck.…”

“…The deck is connected to the main cable by suspensions in 15 points. Width of the model is equal to 0.4 m [24][25]. The elements of the model of the prestressed suspension structure are made of steel cables with modulus of elasticity 60000 MPa.…”

“…To connect the deck with the load bearing cable, adjustable suspensions are used, that allow levelling of the deck. The suspensions are connected to the cables using U-bolt clips [26], see Fig. 10.…”

Hybrid composite cable for prestressed suspension structure

“…The structure is prestressed. The prestressing level is equal to 60% of the main cable load bearing capacity (Goremikins et al 2012b). …”

“…2). Usage of cable trusses allows for the construction of bridges with reduced requirements for girder stiffness, but overall bridge rigidity will be ensured by prestressing of stabilization cable (Goremikins et al 2012a). The deck can be made of light composite materials (Goremikins et al 2010a).…”