Summary: Josh Kirk and Jill Mickelson, two professional engineers from local environmental consulting firm Braun Intertec, will talk about the geology of bridge construction. This presentation will address not only how bridges are constructed, but how they interact with their environment to provide for a safe and stable structure. We will identify how the geotechnical investigation provides key information that guides designers on how to appropriately support their structures, and evaluate how different geologic settings can lead to different bridge foundation approaches. We will also discuss how some of the unique geological settings in Minnesota lead to the need for creative construction approaches as designers and contractors deal with sinkholes, bogs, artesian conditions, bluff stability, river flooding and the like. We will explore some of the related environmental issues that can arise during bridge construction such as dealing with contamination as well as protecting unique and endangered resources. We will share how a strong knowledge of the interactions between the bridge system and the geology of the building site influences a project’s chances at successful completion.

Biography: Jill Mickelson has more than 19 years of experience in the environmental field, providing professional consulting services to private and municipal clients, including the St. Paul Port Authority, City of Waite Park, City of Rochester and the Minnesota Department of Transportation. As a principal engineer, Jill’s experience includes managing environmental construction management, preparing plans and construction documents for demolition and brownfield redevelopment projects, conducting compliance assessments and regulatory permitting, providing coordination of field operations, supervising due diligence Phase I and II Environmental Site Assessment (ESA) and Environmental Assessment Worksheets (EAW), and evaluating remediation strategies for soil and groundwater cleanup.