Analysis Of Mechanical Behavior Of Large Cantilever Connected Steel Structure During Construction In Tianjin Juilliard School

A large number of complex structures appear in large public buildings,it is difficult to build this kind of struction,and improper construction process can cause various problems easily during the construction process and service period.Tianjin Juilliard College,as a large cantilever connected structure consisting of four large cantilevered units and five aerial corridors,is extremely difficult to construct,but the current research on the connected structure has focused on a single corridor connecting two towers,the research on the construction process of this large cantilever connected structure is basically blank.Therefore,this paper uses the research methods of numerical simulation and on-site monitoring to provide reference for related engineering design,construction and scientific research on the mechanical behavior of the large cantilever connected steel structure during the construction of Tianjin Juilliard School.Aiming at the problems of complex interaction between the large cantilevered unit and the corridor of Tianjin Juilliard School,and the different law of internal force distribution during the construction and design stages,this paper uses a numerical simulation method to study the internal force distribution laws of this structure in design stage.And the effects of different overall construction sequences,different temporary support arrangements and unloading orders,and different buckling restrained brace installation orders on the distribution of internal forces after the construction process were determined,and the optimal construction order was determined.Finally,the comparative analysis shows that the internal force distribution in the construction stage has been redistributed compared to the design stage.Taking the concert hall axial force as an example,the axial force of 16.99% of the members has changed its number,and 38.77% of the members exceed the internal force of the design stage.35.41% of the member’s axial force is within the safe range of the design stage,but the overall structure stress is controlled in the safe range.Aiming at whether the internal force difference caused by the construction process and the design stage will affect the static and dynamic performance of the structure during the service period,this paper uses a numerical simulation method.First,three construction processes that heating,cooling,and heating first and then cooling are discussed separately.It is found that the gradual decrease of the temperature during the construction of this type of structure is the most beneficial to the service of the structure in the later stage,and the increase of the temperature is the most disadvantageous to the structure,so it is the most beneficial for the structure to construction in the second half of the year.The effects of the hysteretic performance of the buckling restrained brace under the initial internal force and the installation sequence considering the installation order of the buckling brace on the seismic performance of the overall structure were studied.It was found that the hysteretic performance of buckling restrained brace and the seismic performance of the overall structure were not affected by the construction process,so buckling restrained brace can be installed in advance as ordinary brace during construction.Aiming at the problem that the numerical simulation is too ideal and it is impossible to estimate the influence of many influencing factors on this structure form in reality,a combination of numerical simulation and on-site monitoring is used to monitor the stress changes throughout the construction of the structure,we find that the actual structural stress and the numerical simulation of the stress trend is consistent,but there is a certain gap in the absolute value of the stress.It is found that the structural column is greatly affected by the construction process,and the average stress is magnified by 3 times.The overhanging components are affected secondly,the average stress is magnified by 1.7 times.During the monitoring process,the stress was unloaded ahead of time.Numerical simulations found that this would not have a large impact on the stress of the structure,but it would cause a large burden on the junction of the corridor and the unit.The maximum compressive stress chang from-39.74 MPa to-195.52 MPa,so the structural columns and cantilever beams and the junction of the unit and the corridor need to be strengthened during the design.