University of Washington

• Project: Estimating Future Flood Frequency and Magnitude in Basins Affected by Glacier Wastage • PI: Anna Liljedahl (UAF) Infrastructure, such as bridge crossings, require informed structural designs in order to be effective and reliable for decades. A typical bridge is intended to operate for 75 years or more, a period of time anticipated to exhibit a warming climate and, consequently, hydrologic changes (IPCC 2007). An understanding of present and future possible hydrologic conditions is necessary to avoid damage to critical infrastructure and costly disruptions to Alaska's transportation network. Changes in glacier extent in response to climate warming and/or altered precipitation regimes have the potential to substantially alter the magnitude and timing, as well as the spatial variation of watershed-scale hyrologic fluxes. The dominant goal, as highlighted by the ADOT&PF Bridge Section Hydraulic Squad, is to improve estimates of peak flow frequency and magnitude at bridges crossing glacierized basins. This requires an understanding of the coupled hydologic system (glacier to overall watershed), and therefore, a quantification of the role of glaciers on present watershed-scale runoff before we can estimate how climate warming may affect basin-wide discharge regimes. The project approach will include analysis of a) historic hydrologic data sets and b) complementary field measurements and model simulations to provide refined products that meet ADOT&PF needs. This project's primary objective is to compare estimates of future flood magnitude and frequency between traditional statistical methods, which sole utilize historic runoff measurements, to physically-based hydrologic model projections. -• Project: Phase II Structural Health Monitoring and Condition Assessment of Chulitna River Bridge • PI: J. Leroy Hulsey (UAF) In this study, we will monitor the behavior of the Alaska Chulitna Bridge for the specific purpose of assisting the DOT in performing an accurate condition assessment of this bridge. Based on the state-of-the-art SHM knowledge and technologies with a specific interest in those which could be used on bridges in cold, remote regions, the objective of this study is to provide important information for structural condition assessment of the Chulitna River Bridge. Proposed SHM objectives are listed below—applicable to all bridges: • Develop a SHM protocol including preferred system integrator, software, instrumentation, and sensors suitable for Alaska's remote, harsh weather locations. • Develop criteria to incorporate SHM into the state's bridge management process. The established SHM system for ADOT&PF will be able to monitor performance of bridges subjected to extreme temperature and conditions—an aspect that is very important information for assessment of the structural condition and potential remaining service life of Alaska bridges. -• Project: Investigation of High-Mast Light Pole Anchor Bolts • PI: Scott Hamel (UAF) The Alaska Department of Transportation and Public Facilities owns and maintains over onehundred high-mast light poles that are up to 170 feet tall. These poles are used to illuminate intersections and freeways in the central and south-central regions of Alaska. The poles, which are used throughout the lower 48, have experienced scrutiny in the last decade after a number of catastrophic failures across the country. As part of its review of these structures, the Alaska DOT has found widespread and continual loosening of the anchor bolt nuts at the base of the poles. The design and performance of the poles is based on an assumption of tightened anchor bolts, and the loose nuts endanger nearby traffic and pedestrians. Given their height and proximity to major roadways, collapse of these poles would likely cause significant damage and multiple fatalities. Currently, the state inspects and re-tightens the nuts on each pole on a regular basis, but this is an expensive program and it is not known what level of safety it provides. A more permanent solution is required to ensure the safety of the structures and reduce maintenance efforts. 14 Pacific Northwest Transportation Consortium

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