Time filter

Source Type

Metzger A.T.,University of Alaska Anchorage | Hutchinson J.,Alaska Department of Transportation and Public Facilities | Kwiatkowski J.,Reid Middleton Inc
Marine Structures | Year: 2014

Load demands on ferry berthing structures are not well understood due to lack of information about berthing parameters for ferry-class vessels. Therefore, a great deal of uncertainty exists when designing these structures. Engineers are often forced to make assumptions about the magnitude of vessel impact energy as well as forces imparted to the structures. In order to gain a better understanding of berthing demands on ferry landings, an automated monitoring system was devised and implemented at active ferry terminals. This manuscript discusses berthing parameters of interest when designing vessel berthing structures. It also presents previous work on the topic of measuring these parameters. With modern data acquisition systems, it is possible to collect a much more sophisticated representation of berthing parameters than in the past. This manuscript discusses how a state-of-the-art monitoring system was devised and implemented for the purpose of measuring vessel berthing parameters. This included nearly simultaneous measurement of vessel approach velocity, fender displacement and axial strain in structural components. With this system, vessel berthing parameters and structural response may be actively monitored. The output of the monitoring system is presented here and demonstrates the utility of the system. © 2014 Elsevier Ltd.

Feng Y.,Alaska Department of Transportation and Public Facilities | Kowalsky M.J.,North Carolina State University | Nau J.M.,North Carolina State University
Journal of Structural Engineering (United States) | Year: 2015

This paper investigates the impact of seismic load history on longitudinal bar buckling in reinforced concrete (RC) bridge columns. Previous research has shown that reinforcing bars are prone to buckling upon reversal from tensile strain. To quantify this effect, a hybrid analysis method using both fiber and solid elements is developed and implemented to assess the impact of seismic load history on reinforcing bar buckling. Forty earthquake ground motions are utilized to conduct nonlinear time history analysis of bridge columns using a fiber-based model. The longitudinal bar strain history from the fiber-based model is then utilized as the input to the finite element model. A parametric study is conducted for the purpose of developing design equations that provide strain limits prior to the onset of bar buckling. Simple design approaches are proposed based on the design equations. © 2014 American Society of Civil Engineers.

Stanley D.A.,Alaska Department of Transportation and Public Facilities | Pierson L.A.,Landslide Technology
Geotechnical Special Publication | Year: 2013

Development of Geotechnical Asset Management (GAM) is part of a national effort to implement Transportation Asset Management (TAM) and Performance Management (PM). Recent research is moving development of GAM beyond the initial steps of inventory and condition surveys towards condition forecasting, estimating service life, and setting levels of service and performance standards. Geotechnical assets such as rock and soil slopes, embankments, materials sites, retaining walls and other elements are complex and our understanding of their services lives is incomplete. Means to estimate the condition of these assets and monitor their condition over time are required for a fully functioning asset management program. These steps are necessary precursors to conducting credible life cycle cost analysis. When life cycle costs are determinable, critical geotechnical elements can be included as part of an asset management program. This paper includes discussion of: 1) problems and issues with estimating service life and condition forecasting for geotechnical assets; 2) development of a Geotechnical Asset Condition Index to represent the condition of rock and soil slopes and embankments; and 3) performance measures for rock and soil slopes and embankments. © 2013 American Society of Civil Engineers.

Fulmer S.J.,North Carolina State University | Nau J.M.,North Carolina State University | Kowalsky M.J.,North Carolina State University | Marx E.E.,Alaska Department of Transportation and Public Facilities
Journal of Constructional Steel Research | Year: 2016

Described in this paper is the evaluation of a series of design concepts which attempt to improve the inelastic cyclic response of steel bridge substructures. The bridge system under consideration consists of hollow circular steel piles welded to steel cap beams. Described first is the motivation for the use of this type of structure, followed by a discussion of the research methods which include large scale reversed cyclic testing supplemented by finite element analysis. Next, the performance of the current as-built system, the fillet welded connection, is evaluated. This connection is shown to perform poorly with little inelastic deformation capacity prior to failure. A variety of alternative connections are then proposed and evaluated. These alternative connections include modified weld detailing and plastic hinge relocation approaches. Alternative weld detailing focuses on the complete joint penetration weld with reinforcing fillet welds. The plastic hinge relocation alternatives include a gusseted connection, a reduced column section, and the recently proposed grouted shear stud (GSS) connection. Alternative weld details produce only slight improvement in performance. Of the plastic hinge relocation concepts, the grouted shear stud (GSS) connection offers the most promising approach to improve inelastic cyclic response. © 2015 Elsevier Ltd. All rights reserved.

Stickel J.,Alaska Department of Transportation and Public Facilities | Vandervalk A.,Cambridge Systematics Inc.
Transportation Research Record | Year: 2014

The Moving Ahead for Progress in the 21st Century Act (MAP-21) established a performance-and outcome-based transportation program for safety, infrastructure condition, congestion reduction, system reliability, freight movement, environment sustainability, and reduced project delivery delays. Transportation data are essential in addressing those challenges. Data are valued assets, but they carry a significant risk-bad data can lead to ineffective planning and ultimately to poor agency business decisions. An effective transportation data business plan coupled with institutional data governance can mitigate the risk by providing an approach for delivering comprehensive, quality data. Better data provide better information, which in turn results in informed decisions. A data business plan with an established data governance environment can lead to proactive rather than reactive decisions. Many state departments of transportation have embraced such concepts and best practices and are beginning to apply them in overall data governance. However, the terms and application are not mainstreamed and are not assimilated into the transportation agency culture. This paper provides the context for data management, data governance, and data stewardship; a business need for establishing data governance in a transportation agency; key features to be considered for a data business plan; approaches to developing a data governance program; and finally a process for evaluating data program governance.

Discover hidden collaborations