Ambient Temperature On The Long-span Continuous Rigid Frame Bridge Stress-deformation Of Study

Temperature changes around bridges would lead to the changes of temperature fieldinside the structure, which would inevitably lead to various displacements of components. Forlong-span continuous rigid frame bridge, since the indeterminate structure by nature, so underthe effect of temperature, thermal stress will be produced. During the operation of bridges, inaddition to stress, cracks are mostly caused by temperature. To ensure the safety of bridgeoperation, our country is monitoring long-span bridges, observing the deformation of bridgesand work stress. The thesis focuses on monitoring safe operation of bridges theoretically andpractically, the main contents of the thesis are as follows:（1）The history and present study of domestic and foreign researches on temperaturefield and temperature effects are reviewed, and details of some norms of world’s majorcountries are discussed, basic theory and computational methods of span continuous rigidframe bridge temperature field and temperature effects are also elaborated. Throughdiscussion and analysis, the study found that the temperature effect belongs to hot-structuralcoupled field problem, and is a one-way coupling field. Therefore, we can first calculate thetemperature field of bridge structures, then bridge structures obtained temperature loads,apply temperature loads of the bridge structure to the boundary conditions of the bridgestructure model, analyze and calculate the structure;（2）Observe plane deformation of the bridge structure, the observation adopted staticGPS receiver9600developed by South Mapping, object observed is Luohe Bridge(Huangling-Yan’an section). Each of the four quarters of plane displacement were monitoredfrom the third quarter of2011, and compare them with the data obtained from the first time ofeach quarter to find bridge deviatoric plane displacement. In order to make the comparisonmore intuitively, maps of X, Y direction and the plane vector change map deviation vector aredrew respectively;（3）Based on the environmental conditions and the measured temperature data of Luohebridge, ANSYS model calculation and analysis of the model for the overall heating andcooling analysis are carried on, the heating and cooling of the four quarters of different planedisplacement are found;（4）Through the comparative study of theoretical calculation and measured data, thestudy shows that:(a) theoretical results and experimental results are basically consistent;(b)along with periodic variation of temperature, displacement of bridges would return back to position from varied temperature of different seasons, which means it is caused bytemperature effects rather than the force of the non-structural displacement or offset caused byfactors such as the structure itself.