The traditional bridge evaluation process contains uncertainty that affects management decisions. Numerical models require assumptions regarding structural response, and code load models are inherently conservative to ensure uniform applicability. This research investigated how structural monitoring could reduce uncertainty in the evaluation and management process. Targeted instrumentation was implemented on the MacKay Bridge. Controlled load testing was conducted to refine an existing numerical model. Long-term monitoring was completed to compare extreme in-situ traffic effects with the Canadian Highway Bridge Design Code. Throughout the project, accuracy of information collected was a priority; deviation from code recommendations requires absolute confidence in the data. Outputs from controlled testing indicated that the existing numerical model for load distribution and structural response required minimal tuning. Long-term testing indicated that actual load effects are less than code requirements. Results from this thesis show that structural monitoring can reduce uncertainty in structural evaluation and management decisions for infrastructure.

Bats are known and documented to use bridge structures as roosts in various locations throughout the United States and abroad, but there is limited knowledge of how bats use bridges in New England. Significant population declines due to White-Nose Syndrome have resulted in several bat species being listed as state or federally threatened or endangered. If bats are using bridges as roosts, significant effort is required to ensure they are not disturbed or harmed during construction or maintenance work, requiring knowledge of assessment methods to identify likely roost locations in bridges. This thesis describes a two summer study evaluating the bat roosting potential in New England bridges. During this study, 191 bridges were rapidly screened throughout New England for bat roosting potential, with eighteen selected for more detailed evaluations. Various monitoring techniques to determine bat roosting potential were assessed at each bridge evaluated, including acoustic monitoring and analyses, infrared imaging, borescope inspection, visual inspection, emergence studies, and guano testing for species identification. The current federal form required to assess bat roosting in bridges slated for construction work was assessed for its appropriateness in the New England region. A supplemental form has been developed through this study that is recommended to be used in conjunction with the federal form to better assess roosting potential in New England bridges. Training and collaboration is also recommended for personnel completing forms and inspectors familiar with state bridges. When the study began, there was only one known bat bridge roost in New England known. After this two summer study, thirteen bridges have been positively identified as bat roosting sites in New England, with possible roosting at several other bridges. Information gathered through this study on bat roosting potential in bridges and the various monitoring techniques evaluated to positively identify bat roosting in bridges can be used as guidance for state Transportation Agencies developing protocol for construction at potential roosting sites.