Prestressed Concrete Continuous Rigid Frame Bridge Construction Camber Setting And Temperature Stress Analysis

With the progress of science and technology constantly,the application of prestressed technology and constantly improve the concrete material performance,the application of prestressed concrete continuous rigid frame bridge at home and abroad is also more and more.In the prestressed concrete continuous rigid frame bridge construction,the need to carry on the construction control,the main contents in construction control is the linear control,and set up in the process of the camber is the most important in linear control.Creep deformation on the construction of prestressing camber setting influence is bigger,because of the influence of creep factor is very complex,so it is need to be considered in the process of design and construction of long span continuous rigid frame is an important problem.At the same time,concrete continuous rigid-frame box girder is in under the action of temperature field,can produce temperature stress,it is lead to disease is one of the main factors.This paper,taking the middle bridge as the engineering background,using Midas/Civil and Ansys software to establish the finite element analysis model,and on the basis of the relevant work is as follows:(1)In view of hanging basket deformation values of the model the influence of the elevation values,in the process of the construction monitoring,step by step load test of hanging basket,it is concluded that the load value and deformation displacement curve of the relationship,the correction,the story end up with a revised linear regression equation,according to this equation can accurately predict the hanging basket deformation value,to guide the bridge construction is of great significance.The value of the basket is very important in the vertical mode,and the construction process should not be ignored.(2)For creep deformation of the prestressing camber values,the effects of the different creep specification used in the finite element model of long span continuous rigid frame,the dead load,live load,1/2,China(JGT D62-2004),American ACI creep model CEB-creep model and Europe FIP creep model of camber values.According to the data that caused by the dead load camber value maximum,1/2 live load prediction of minimum value camber,although each creep model data is different,but the trend is roughly the same size.Three creep model of the proceeds of the prestressing camber are differences,European CEB-FIP than China(1990)model specification(JGT D62-2004)model,and the ACI model than China specification(JGT D62-2004)model.Comprehensive domestic many continuous rigid frame bridge across the middle scratch problem,considering this kind of bridge creep effects on pre camber setting,it is recommended to use the ACI model calculated value.(3)Zhongpai bridge site based on the actual measurement of temperature field of the relevant data,combining the finite element software ANSYS model to calculate the data,compare both the continuous rigid frame bridge is obtained the temperature field and temperature stress of concrete box girder of related research results.The results show that the box girder temperature gradient of the solar radiation intensity and the highest temperature difference has the greatest impact,box girder roof temperature change,the biggest changes in the web times,the change of the base plate minimum;Temperature stress is the most unfavorable moment of the day,16 of box girder cross section temperature stress change laws of basic is sinusoidal in time.At the same time for box girder temperature stress related measures are put forward.