Analysis On Wind-induced Vibration Of Super High-rise Main Tower And Attached Tower Crane During Construction Period

Wind load is one of the main control loads for super high-rise buildings' structural design,as they are typical wind-sensitive structures.At present,most of the research on wind resistance of super high-rise buildings is based on the complete structural model after completion,and little consideration is given to the structural wind resistance in the time-varying state of the construction phase.However,as the height of super high-rise buildings increases,the construction period becomes longer and the construction becomes more difficult.The high-rise building is a time-variable structural system with variable structure,variable stiffness,and variable load in a long construction period.Tower cranes and other equipment are attached to the main structure.At this time,the wind-induced response cannot be calculated according to the model of complete structure after completion.Therefore,it is imperative to study the wind-induced response of the super-high-rise time-varying structures and attached tower cranes during the construction period to ensure safe construction.In this paper,the CFD numerical simulation technique combined with the finite element method is used to analyze the surface wind pressure and the wind-induced vibration response of the main structure during construction,and the failure path of the construction tower crane under extreme wind is studied.Mainly complete the following work:(1)Based on Fluent 15.0,the CAARC standard model was simulated and compared with the wind tunnel data to verify the effectiveness of the numerical simulation method.The distribution of wind pressure on the surface of the main structure of a super high-rise building in two construction stages was analyzed.The influence of the change in building shape on the surrounding wind field was discussed.The wind pressure isolines of the building surface and the distribution of the flow field around the building under different wind directions and different wind speeds were also given,thereby determining the most unfavorable wind direction under the two phases.(2)The value of wind loads for super high-rise buildings in the construction phase was determined,and the average wind load value was given according to the principle of consistency of surpassing wind probabilities.The fluctuating wind speed generation program was compiled based on the linear filtering method.The finite element analysis models for a number of construction stages of a super high-rise building were established,and wind-induced displacement and acceleration responses were calculated.The influence of the specific tower crane working conditions on the wind-induced response of the main structure was discussed,and the most adverse tower crane operating conditions were obtained.With the wind load as the control load,the maximum number of core wall leading the construction was calculated.The influence of different wind spectrum and wind speed on the wind-induced response of the main structure during the construction phase was analyzed.(3)With a tower crane as the independent analysis object,the wind-induced vibration response of the tower crane under different construction stages was calculated by the equivalent static method and the dynamic time history method respectively.The rationality of the wind vibration coefficient in the tower crane specification was discussed.The primary-secondary structural mechanics model of the tower crane attached to the main structure was established.The influence of the main structure on the wind-induced vibration response of the tower crane was analyzed based on the time-history method.It was found that as the construction height increases,the influence of the main structure on the tower crane will gradually exceed the wind-induced response.The failure path and wind resistance curve of the tower crane were obtained by wind-induced pushover analysis.Based on this,the wind-induced vulnerability analysis of the tower crane was performed.The wind-induced vulnerability curves and failure critical curves of the tower crane at various performance levels were obtained.