A Probabilistic Analysis Of Operation Of A Flat Steel Frame Under Seismic Action

The seismic action is non-stationary random process. Calculation in the probabilistic setting makes it possible to most accurately assess the response of the system during an earthquake. In the work, the reliability of a flat steel frame under seismic action was estimated by the method of statistical tests when considering seismic action in the form of a non-stationary random process. The design cross-sections of the frame were adopted based on the results of the calculation of the seismic action of the design earthquake level in accordance with current design standards. When performing the probabilistic calculation, a deterministic solution implemented in the software package was used. The solution is based on direct integration of the equations of motion using explicit schemes. A method has been developed for determining the actual value of safety coefficient of load-bearing capacity of the frame. Considering the safety factor of the frame under seismic action as a random variable, a corresponding histogram is constructed using the criterion of non-collapse. Using the Pearson criterion, the closest theoretical distribution law to the obtained empirical distribution is determined. According to the theoretical laws produced, the assessment of the actual safety factor of the bearing capacity and the coefficients taking into account possible damage to buildings and structures with a given security. In addition, the probability of plastic deformations exceeding the value of 0.05 in the structural elements in case of accidental seismic impact of the maximum calculated earthquake level was established by statistical tests. The method is used to determine the seismic stability of structures with a given security, which makes it possible to provide the required level of reliability for all buildings and structures designed in seismic areas.