Determination of prestressing levels for cable trusses as a function of their stability
The stability of prestressed cable trusses subjected to static and dynamic loads is analysed in the paper. The stiffness of the elastic cable truss system was varied by changing the prestressing force. Modelling results for different levels of tension show that, in terms of satisfying dynamic resistance conditions, a much greater tensile force is required for cable grids with diagonal members, compared to those with vertical rods. The conclusions derived constitute recommendations for the use of calculation methods, as well as for the determination of prestressing forces under which stability criteria are fulfilled.
Influence of the climate on large scale cable structures: A case study of Khan Shatyr entertainment center in Astana, Kazakhstan
The purpose of our study is based on the structural examination of large scale cable structures built in different climatic conditions. Firstly, the study identifies construction methodology and typical problems related to cable structures. Later history, function, construction methodology, and materials have been studied in order to investigate the conception of the structural cable system to evaluate large scale structures worldwide. Historical background review has been done to chronologize the development of cable structures and the appearance of new elements and materials used in combination. The influence of the climatic conditions of specific regions on cables has further been examined in order to indicate possible solutions for the existing problems. As a result, tables on a comparative study of large scale cable structures in different regions have been presented. Khan Shatyr Entertainment Center, located in the capital of Kazakhstan, was chosen as a case study to reveal the construction methodology of large scale cable structures considering the impact of the climate. Evaluation of the case study displays that climatic impact was properly considered on the design stage, increasing structure stability. In addition, the article suggests that this type of structural system is suitable for all climatic regions.
Influence of some factors on the aerodynamic behavior of long-span suspension bridges
As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed (including the vertical and horizontal variations) all increase consequently, which may have unnegligible influence on the aerostatic and aerodynamic behavior of long-span suspension bridges. In this paper, the models of aerostatic and aerodynamic forces are established, in which the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed are both considered. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic and aerodynamic behavior of the bridge are investigated analytically. The results show that the aerostatic behavior is significantly influenced by these factors, but for the aerodynamic stability, it is greatly influenced by the nonlinear wind-structure interaction and the horizontal variation of wind speed, and the other factors have no influence on it.