The Research Of Temperature Field And Temperature Effect Of Box Girder Bridge By Solar Radiation

Temperature stress is an important factor for cracking of the concrete box-continuous girder bridge.And the temperature stress which caused by solar radiation has the largest influence.The different temperature gradient is likely to lead to extraordinary disparity of temperature stress.So it will be necessary for us to research thermal field and temperature effect of the concrete box-continuous girder bridge and to get temperature distribution rule which will be fit for the box-continuous girder bridge in our country.And the construction control of this box girder bridge will be guide to the right way.Taking the construction control of left side bridge of approach span of bridge crossing the chang jiang river in Wuhan as example.Thermal field and temperature effect of this long-span prestressed concrete box-continuous girder bridge will be observed uninterrupted in 24 hours.After researched large numbers of documents and actual measurement data,all kinds of parameter which would be used to calculate thermal field of box-continuous girder bridge should be fixed.The plane model of this bridge will be established by the finite element program ANSYS to simulate thermal field of box-continuous girder bridge.The inosculation situation between the result and measured value will be done from the contrastive analysis.It also proves that the finite element program ANSYS can simulate the thermal field is technically feasible.The vertical temperature gradient curve which is the foundation of further calculation will be fitted from computational solution and measured value.The parametric analysis which related to thermal physical parametric will be also carried out to research the distribution of thermal field of concrete box-continuous girder bridge and to get the influence situation of thermal field of box-continuous girder bridge under different value of thermal physical parametric.Based on the actual construction condition,the solid model of T construct will be build by the finite element program ANSYS to calculate the flexure and stress of box-continuous girder bridge under solar radiation.The time interval curve of tip flexure of T construct box-continuous girder bridge which is temperature-dependent will carry out.The result of contrastive analysis between measured stress and finite element calculated value of the root section of T construct will verify the validity of the vertical temperature gradient curve.Taking construction period and economical efficiency into consideration,the construction method of setting without closing segment on side span of long-span box-continuous girder bridge has been widely used and is influenced by temperature tremendously.The variation flexure of the bridge by temperature fluctuation can cause cracking of bridge joint.In order to understand temperature effect on the role of this construction method.Taking side span closure of a long-span box-continuous girder bridge in Wuhan as example.It introduces applying the finite element analysis software ANSYS to simulate nonlinear temperature field ofΠstructure box-girder and analyses deflection and stress result ofΠstructure under the effect of temperature.It also researches the method to eliminate the effect of temperature and proves the mobility of construction method of setting without closing segment on side span.