Engineering assessment method of reliability indexes of steel trusses bars
Journal Title: Вісник Одеської державної академії будівництва та архітектури - Year 2017, Vol 1, Issue 66
Abstract
The simplest methods of evaluating reliability indicators of building structures elements based on the representation of the strength characteristics and stress in the form of random variables do not take into account the lifetime of the structure. Submission of variable loads in the form of quasi-stationary random processes with actual distributions ordinates requires a fairly complex computational procedures. The offered method of evaluating probabilities of failure of steel roof trusses rods is based on the representation of the characteristics of strength of the material and constant load in the form of normally distributed random variables and snow load ‒ in the form of a sequence of annual maximums described by Gumbel distribution law. Such approach allows for a fairly simple formula to estimate reliability indexes considering design service life by switching from annual heights of the distribution of variable load to the maximum allocation for the entire service life. The developed method is illustrated by an example of calculation of steel roof trusses rods in various combinations of permanent and snow load. The farms with parallel chords span of 24 meters are examined. Dependences of the level of reliability of rods in Bell (logarithm of the probability of failure with the sign «minus») on the level and structure of bars loads are analyzed. The level of reliability decreases with increasing utilization of the bearing capacity of rods and with the growth of variation coefficient of the reserve of load capacity. Despite the simplicity, the developed method can adequately take into account the characteristics of loads, design features and service life in the assessment of the reliability of farms rods.
Authors and Affiliations
Victor Pashinsky
Decorative concrete with hybrid glass fibre: design and first results of the experiment
The first results of experiment in the study aimed at getting high performance decorative concrete are presented. Varied in the experiment were the content of zeolite as active mineral additive, ratio of fine to coarse s...
Research of slab patterns from ceramsite concrete on multicomponent astringent
The results of the experimental research of load-bearing capacity and deformation capacity of patterns of the assembly- monolithic and monolithic slab from сeramsite concrete on multicomponent astringent and quartz sand...
Differential equations of the spatial bending of reinforced concrete beams and frames, taking into account physical and geometrical nonlinearities and plasticity of concrete
In solving static and dynamic problems for reinforced concrete frames based on nonlinear and plastic properties of materials in order to achieve sufficient accuracy, it is necessary to make reinforced concrete frames ele...
Application of the ground penetrating radar method for the Ukrainian railways
The article analyzes the condition of the earth roadbed on the railways of Ukraine, the requirements for it and the methods of monitoring. The attention is paid to the importance of monitoring the state of railway infras...
The pipeline monitoring
Experience of monitoring of high pressure gas pipeline laid on steep slope area above the underground workings is outlined. For research the geodetic reference network consisting of four points was established on the sit...