Surveillance of the Performance of Elastomeric Bearings in Marylands Concrete Bridges

Abstract

This thesis presents an investigation of the performance of elastomeric bearings in concrete girder bridges. Varying design practices create unpredictable performance in the field. The goal of the research is to correlate the AASHTO design parameters to a bearings performance in the field and further to make recommendations to improve as well as reduce the variability of the design for elastomeric bearings.

A field study was performed to collect data on the condition of bearings in over 80 bridges. Each bearing was given a PONTIS condition rating in order to quantify the level of degradation and to perform analysis. The results from a spreadsheet analysis were either confirmed or rejected using a logistic regression analysis of the field data. Finite element analysis was used to verify preliminary recommendations from the field study and logistic regression.

This study can conclude that limitations should be applied to the combined compression and rotation, the shape factor and the shear strains in elastomeric bearings.