Date of Award:

5-1-2014

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Civil and Environmental Engineering

Advisor/Chair:

Paul J. Barr

Abstract

In order to more accurately quantify the behavior and degradation of bridges throughout their service life, the Federal Highway Administration lunched the Long-Term Bridge Performance Program. As part of this program an I-girder, integral abutment bridge near Perry, Utah and a two span, box-girder bridge south of Sacramento, California were instrumented with foil strain gauges, velocity transducers, vibrating wire strain gauges, thermocouples, and tiltmeters.

In this research study, data from the thermocouples was used to calculate average bridge temperature and compare it to the recommended design criteria in accordance to the 2010 LRFD Bridge Design Specifications of the American Association of State Highway and Transportation Officials (AASHTO). The design maximum average bridge temperature defined in the 2010 LRFD Bridge Design Specifications was exceeded for both bridges. The accuracy of the 1991 Kuppa Method and the 1976 Black and Emerson Method to estimate the average bridge

temperature based on ambient temperature was studied and a new method that was found to be more accurate was proposed. Long-term predictions of average bridge temperature for both bridges were calculated. Temperature gradients were measured and compared to the 2010 AASHTO LRFD Bridge Design Specifications and the 1978 Priestley Method. Calculated flexural stresses as a function of maximum positive and negative temperature gradients were found to exceed the service limit state established in the 2010 AASHTO LRFD Bridge Design Specifications in the case of the California bridge.