Construction Site Monitoring And Numerical Simulation Analysis Of Large Span Cantilever Steel Structure

The large span cantilever steel structure is novel and unique in shape.The structure improves aestheticism of building and the use of space,but also increases the architecture of complexity and difficulty of construction,long construction cycle,uncertain factors during the construction period.Structural design and construction of large span cantilever steel structure is significantly different from other traditional structures in the process of structural design and construction,so the construction process can not be carried out in accordance with the traditional construction technology.Compared with the traditional construction,the construction of large span cantilever steel structure is difficult,and the related engineering experience is little,and the influencing factors are more,therefore,in order to ensure the safety and smooth operation of the project,the construction process of the large span cantilever steel structure is analyzed,especially the change of the internal force of the steel truss during the unloading process of the temporary support.In the whole construction process,simultaneously monitoring of the stress change of the key members of the large span cantilever steel structure,then the theoretical value and the monitoring results were compared and analyzed to determine the reasonable unloading sequence of temporary support.This is of great significance to ensure the construction safety.Base on the large span cantilever steel structure of Huarun Vanguard Shopping Mall in Huzhou,Mainly to complete the following tasks:(1)At first,this paper briefly introduces the structural system and its special force transmission method.Then the development process of the health monitoring of large structures and the status of domestic and foreign research are summarized and analyzed systematically.(2)The methods of unloading the temporary support of the large span cantilever structure are summarized.Base on construction mechanics and Analysis methods of construction in stages which analyses the process of construction for the large span cantilever steel structure.Study and analysis on the transmission mode of the large span cantilever steel structure,so as to determine the control requirements,the basic principles of unloading and the reasonable unloading sequence of the temporary support unloading.(3)Use the finite software-MIDAS GEN to build the finite element analysis model.Simulate the unloading process of temporary supports of the large span cantilever steel structure and the process of formal concrete pouring,and analyze the stress of the key members and structural deformation.(4)According to the field situation,put forward reasonable monitoring point layout principle.Describe in detail installation process of vibrating wire strain gauge of the large span cantilever structure and monitoring data collection.The measured value and the theoretical value are compared and analyzed,then the results show that the monitoring data is reasonable and reliable.At the same time,it also verifies the correctness of the simulation method used in this paper.(5)The modal analysis of large span cantilever steel structure is carried out,and obtain its natural frequency and vibration mode.The seismic response analysis of large span cantilever steel structure was carried out by using the time history analysis method of Midas/Gen,then obtain the time history response curve of the angle of the cantilever truss.At the same time,check the elastic displacement between the maximum layers.At the end of this paper,summarize the research work in this paper,then provide some practical construction experience for similar projects and point out some questions need to be solved in the future.