| This paper is based on the project ‘Research on the key technology of large span arch bridge combined porous wide beam’,which is a science and technology project from Housing and Urban Construction Bureau of Ankang.Adopting an in-depth research on selection of asymmetric closure of the construction sequence,the cross-cast section of the cross-cutting time,temporary constraints to lift the timing,and so on which questions encountered Ankang City East Han River Bridge t by cliterature review and numerical analysis.The main work and achievements as follows:(1)The finite element model of full bridge is established by using MIDAS CIVIL software,and the whole construction phase of the main beam is simulated.The internal force and deformation of the main girder of the bridge under different closing sequence scheme are analyzed.Distribution of Internal Force in Bridge Phase.The results show that when the temporary restraint of the pier is present,the non-span beam construction is less affected.Eight different and dissimilar collapsing sequence scheme,the bridge construction stage of the force,deformation and bridge after the bridge of the internal force distribution is different,which by the edge to the middle of the symmetrical closure of the closure of the order of the optimal.(2)The finite element model of the full bridge is established by using MIDAS CIVIL software,and the different dismantling time of the mid-span cast-in-place section is compared and analyzed.The influence of different time on the internal force and linear shape of the inter-As well as the feasibility of the construction of the program and bridge the bridge of the rationality of the force.The results show that,although the scheme is different,the removal of the stent in the middle span of the span has no obvious effect on the lateral and secondary span,And the arch ribs affected by the larger.Although the main beam after the closure of the arch before the erection of the sowing,can minimize the impact on the arch ribs,but before and after landing the main beam vertical displacement difference of 25 cm,resulting in the removal of the stent is difficult,or even impossible to remove.After the completion of the boom tension to remove the cross-cast section of the stent,regardless of the ease of removal from the stent or the impact on the structure(structural force,linear)are the best of the four programs.(3)The finite element model of the full bridge is established by using MIDAS CIVIL software.The influence of the temporary restraint time on the bridge structure is analyzed and compared.The influence of the temperature gradient load on the bridge structure is introduced.The effects of different temporary restraints on the structure The influence of the upper and lower structures of the bridge and the influence of the temperature gradient load on the internal force of the bridge during the construction of the bridge.The results show that the control accuracy and the accuracy of the linear control of the bridge are easier to be achieved if the temporary constraint is delayed after considering the effect of temperature.If the temperature effect is taken into account,the delay of the temporary restraining time will cause the pier body to bear the secondary internal force caused by the temperature,which causes the safety of the pier body in the construction stage to meet the requirement. |
