Study On Temperature Stress Field Of Orthotropic Plate Steel Box Girder Bridge

Most modern steel structure bridges use steel as the main structural material and asphalt concrete as the pavement material.Steel is more sensitive to temperature in the two types of materials,so steel structure bridges will produce greater temperature secondary stress and deformation under the action of temperature difference.In order to get the actual effect of temperature on steel bridge,especially in Hohhot and other areas with obvious climatic characteristics of their own.Establishing a temperature model suitable for a specific area to reflect the actual temperature field has practical significance for the stress impact of steel structure bridges,and can also provide reference for the design and construction of similar bridges in Hohhot area.Based on the orthotropic steel box girder bridge across Ordos Avenue in Hohhot,temperature sensors are arranged at different locations of the cross section of the steel box girder bridge.Temperature data are monitored at different locations of the steel box girder in one year,and the law of temperature change is analyzed.The most disadvantageous temperature gradient model in Hohhot is fitted and compared with the temperature gradient model in many national codes.According to heat transfer theory and finite element theory,the temperature boundary conditions are determined,and the temperature stress field of steel box girder bridge is solved by finite element software.The main conclusion is that there are obvious vertical temperature difference between the South and north sides of the Ordos Street cross-line orthotropic steel box girder bridge in Hohhot City due to the uneven sunshine.The transverse and vertical temperature difference caused by the uneven temperature makes the temperature distribution of the steel box girder bridge uneven and asymmetrical,which is easy to produce transverse uneven displacement.The maximum displacement is 6.75 mm.The maximum tensile stress of the steel box girder pavement can reach 4.2 MPa.Long-term action of the tensile stress on this position can easily lead to cracking and failure of the pavement.The maximum temperature stress of the steel girder appears near the flange plate,the maximum value can reach 22.1 MPa,and the maximum transverse temperature stress difference is 19.77 MPa.