Análisis no lineal de cables y su aplicación para puentes atirantados y colgantes

Abstract

The effect of deformations in structures that use steel wire or rope is such that redistribution of stresses are produced in the systems. For this reason, this type of structures must be analyzed using a nonlinear static procedure. This thesis work contains proposal methodologies for solving cable structures under the action of gravity loads by using non-linear static analysis. MATLAB programs were made and a cable stayed bridge and a suspension bridge were analyzed. The objectives of the analysis are to propose a constructive precamber that leads to the desired deck level under service loads, as well as to know the stress state and displacement in any constructive stage. The proposed methods consider only the effect of punctual vertical forces applied on the cables in addition to several simplifications to idealize the situations. For the cable stayed bridge an analogy with a continuous beam is considered to obtain the punctual vertical external force that are applied in the cables. This analogy also allows to consider the deck’s resistance to vertical displacement. For the suspension bridge the following consideration is made: for a deck section between two hanging cables, the loads applied to it are supported by only the outer cables. Several models were analyzed with SAP2000 to validate the methods. Similarly the obtained results were compared with no simplified models solved by nonlinear analysis. Finally, the algorithms were used to analyze specific constructive stages.