Probability Distribution Characteristics of Horizontal and Vertical Mechanical Properties of Rubber Bearings

Rubber bearings are widely used to protect civil structures from destructive earthquakes. The mechanical properties of the bearings are the key technical parameters that determine the seismic isolation performance of isolated structures. To estimate the probability distribution of the mechanical properties related to rubber bearings (including horizontal stiffness, vertical stiffness, post-yield stiffness and yield force) under seismic events. Typical natural rubber bearings (NRBs) and lead-core rubber bearings (LRBs) were designed and fabricated, and the bearings were subjected to repeated load tests using a compression-shear testing machine. The test results of the horizontal and vertical mechanical properties of the bearings in the tests were basically consistent with the design values, and the rubber bearings showed stable mechanical behavior under repeated cyclic loading. The statistical analysis of the test results revealed that the relevant mechanical properties of the NRB and LRB specimens followed a lognormal or general extreme distribution with coefficients of variation mainly ranging from 0.86% to 5.6%. The dispersion of the yield force of LRB was the largest in the repeated tests of many mechanical parameters of typical rubber bearings.

Automated summary

This study investigates the probability distribution of the mechanical properties related to rubber bearings in seismic events. Through repeated load tests on typical rubber bearings, it is found that the horizontal and vertical mechanical properties of the bearings are consistent with the design values and exhibit stable mechanical behavior under cyclic loading. The statistical analysis reveals that the mechanical properties of the bearings mainly follow a lognormal or general extreme distribution. The yield force of lead-core rubber bearings shows the largest dispersion among the various mechanical parameters of typical rubber bearings.