Large Span Steel Truss Girder Cable-stayed Bridge Temperature Effect Analysis

When bridges prolonged exposure to solar radiation and environmental factors due to temperature changes, the uneven distribution of non-linear temperature will cause a significant impact on the temperature effect. Studies have shown that the time-varying temperature loads, large-span bridges will have a very serious effect of temperature:When the frequency changes caused by temperature changes of 4%,the structural rigidity of the response will reach 8% of the variation.Under strong effect of temperature loads, large bridges in the use of the same easy-cause strong nonlinear thermal effects,thus resulting in very severe stress concentration and deformation, which will further lead to damage to the bridge structure degraded even further weakened bridges’ use,and can not meet its applicability and durability. In some cases, the structure of the variable load which cause by temperature does not weaker than normal load,and in some cases,even decides the structure safety.In this paper,which use the background of Xinjiang’s first cable-stayed road engineering-Guozigou Bridge,in cold region, mechanics behaviors of bridge structure that affected by temperature is analyzed.First describes the current situation and development of cable-stayed bridge, and research purpose, significance and background of engineering and research methods.Collected literature depth research on the temperature, in theory, the measured of current research and issues of concern to do more to detail,and analyzed the impact States highway bridge specification requirements for temperature effects.The reason for the formation of the bridge temperature load,and the main factors, classification and characteristics of discussion one by one, and introduced the more commonly used temperature loads theoretical formula nowadays.Introduced the model of Midas/Civil which background of Guozigou Bridge,and give a brief description of its functionality and classification of temperature analysis,using elevated steel truss vertical upper temperature simulated solar irradiation to steel truss, when the steel truss itself, towers, cables and stress, displacement, and a detailed analysis of changes in the value, got a certain conclusion.Made a brief theoretical of domestic tower bridge pier with temperature load and thermal stress calculation progress,and made models of tower-cable stayed background of Guozigou Bridge,according to Standards,use for three kinds of conditions with towers,steel truss beams and cable force,done a detailed calculation of the impact analysis and draw some conclusions.Discussed the influence of difference between annual average temperature and system temperature on bridge,relevant conclusions through comparison the temperature effect between tower,main beam and cable force.