Probabilistic Model Of Variable Actions And Reliability Research Of Industrial Building Structures

Compared with the civil building structures,the using environment of the industrial building structures is more complicated.The reliability management requirements are higher.However,the current reliability analysis of industrial building structures is not complete,mainly in the following: First,for its variable actions,referring to the crane load,the floor live load and the dust load,there are no load probability models established to reflect their randomness varying characteristics.It is difficult to consider the effects of these typical actions in industrial buildings reliability analysis.Second,for the crane load with time and spatial variability,a probability combination method with stochastic process and random field-based has not been established.It is difficult to reflect the general working conditions of multiple cranes.Third,the analysis of the reliability of industrial buildings,without considering the probability model of typical variable actions,cannot accurately grasp the level of reliability control of the design and assessment specifications.Based on the above research status and deficiencies,this paper firstly solved the modeling problem of the variable actions in industrial buildings,and then analyzed and checked the industrial buildings design and appraisal rating to reveal the hidden reliability control level of the design and evaluation.Finally,it proposed some suggestions of the reliability contral in the process of the design,use and maintenance,based on the load analysis and the design and assessment checking results.The main contents are as follows:1.Determining the probability model and model parameters of the variable loads(the crane load,the floor live load and the dust load)of industrial buildings,according to the load properties and characteristics,research data,related experiments,statistics and modeling theory.2.Explaining the probabilistic combination method of multiple actions,and establishing the reliability analysis model with combining the probabilistic model of the structural performance and the combined effect of the structures,giving the calculation method of the component reliability index,and explaining the basic method of the structural reliability analysis and checking according to the stochastic process probability model.3.Checking the reliability index of the typical components of industrial buildings(the crane beam,the frame column,the floor board and the roof frame)designed with the old and new design methods,with considering the variable load probability models,to reveal the design reliability control level,and analyze the rationality of the old and new design specifications,and to improve some rational suggestions.4.Checking the reliability index of the typical components corresponding to the threshold values of the ‘industrial building reliability appraisal standard’,with considering the variable load probability models of industrial buildings,to accurately reveal its implicit assessment reliability control level.5.Correcting the reduction factors of multiple crane combinations in industrial buildings design according to the principle of the consistency of the reliability and guarantee rate,and pointing out the technical management measures of the dust load control,for the actual investigation data of the above-mentioned variable effects and the issue of the reliability checking results,with considering the application of structural reliability control theory in industrial buildings,and to put forward some reasonable suggestions for the reliability contral of industrial buildings.In a word,this paper established a complete reliability analysis method of industrial building structures,from the variable action probability model,the variable action probability combination method,and the structural reliability analysis and checking method.Based on the foundation,the design and evaluation reliability control levels of industrial building structures were checked,and the reliability contral suggestions based on the reliability theoretical were proposed.