Vibro-dynamic testing of a 6-story building and reliability assessment taking into account deformation nonlinearity

Abstract

The paper presents the results of vibro-dynamic testing of a 6-story residential building constructed in an area with a seismic intensity of 10 points. The novelty of the study lies in the full-scale testing of a six-story monolithic building and the subsequent use of the test results to calculate reliability as the probability of failure-free performance. The results obtained make it possible to predict the behavior of the building under seismic action. Structurally, the investigated building is a spatial cross-wall system. The basement and above-ground floors are made of monolithic reinforced concrete structures. The dynamic loading is generated by an inertial vibration machine. Vibration measurements were carried out using a digital instrumentation and measurement system. It is shown that the building deforms nonlinearly. The stiffness of the “test object–foundation” system decreased by a factor of 2.14 compared with its initial stiffness, while the stiffness of the object’s “structural system” decreased by a factor of 1.37. The dissipative forces of the building were studied. The logarithmic decrement of vibration was constant and equal to 0.46. The coefficient of nonlinearity changed approximately twofold. Based on experimental deformation diagrams, the reliability W (probability of failure-free operation) of the building was calculated. For this purpose, the statistical simulation method (Monte Carlo method) was applied. Reliability and failure values were obtained for three values of internal viscous friction. The accuracy of determining reliability and failure values was assessed by studying the convergence of the process with an increasing number of artificial accelerograms. The results allow the building to be considered seismically resistant at high acceleration values at the foundation.