Monitoring Analysis And Structure Safety Evaluation Of Large-span Space Steel Structures During Construction

As China's economy increasingly develops in the recent decades,people pay more attention to the culture and technologies.Therefore,more and more complex space steel structures come into being.Moreover,the popularity of large-span space structures impulse the development of construction technologies.However,the safety of large-span steel structures is possibly affected as a result of the complexity of the structure system,its hoisting in the construction programs,and inherent defects of steel structures in fatigue,stress concentration,connectio n,material properties,wielding etc.Therefore,it is meaningful theoretically and practically to analyze the construction and dismantlement,to carry out health monitoring and to evaluate the structure safety.This paper introduces mechanical research analysis theory,numerical simulation method and structure safety evaluation theory(fuzzy theory,analytic hierarchy process)applied at the construction stage of large-span structures.Here I take Linxia grand theatre steel structure roof as an example for engineering research to study several questions as follows:(1)Simulating the construction and the dismantlement process of the grand theater steel structure roof with ANSYS software;Analyzing the dismantlement controlled by the different ways of construction and dismantling;Comparing and analyzing the different controlling methods.(2)Confirming the construction and dismantlement programs after trying sorts of dismantling methods;designing the layout of health monitoring stations through simulating and analyzing the construction and dismantlement process;monitoring and detecting stress and deformation of the theatre steel structure roof in the construction and dismantlement process,and analyzing the monitoring data.It turns out that data detected is almost in accordance with simulation values.(3)Because the safety level of the grand theater steel structure roof can't be evaluated accurately according to health monitoring results.This dissertation,applying the secondary fuzzy comprehensive method and the analytic hierarchy process,with the combination of experts' experience and information from the documents,establishes weight vector and its judge matrix for parts of the grand theater steel structure roof to evaluate the structure safety,which guarantees safety evaluation accuracy.