All posts by trac

Many state departments of transportation, including the Idaho Transportation Department (ITD), are transitioning from pavement design procedures based on the AASHTO 1993 Design Guide to the AASHTOWare Pavement ME Design (Pavement ME). Pavement ME requires that more than 100 design input parameters be defined. To ease this seemingly overwhelming process, a hierarchical approach using three levels is incorporated into the Pavement ME software for defining the inputs. For Level 1, site/material-specific inputs are obtained through direct testing or measurements. For Level 2, inputs are obtained through empirical correlations. And for Level 3, inputs are simply defined as national average default values already embedded in the software. Over the last four years, ITD, with assistance from the University of Idaho, has made substantial progress toward defining the inputs at levels 1 and 2 for flexible pavement design. However, similar efforts have yet to be made for rigid pavements. One of the first steps is to develop input libraries for ITD portland cement concrete (PCC) paving mixtures. Therefore, the main objective of this research is to develop and establish a material database for the PCC mixes in Idaho that are required to implement the Pavement ME Design for PCC pavements.

Principal Investigator: Somayeh Nassiri, Civil and Environmental Engineering, WSU
Sponsor: Idaho DOT
IDT Project Manager: Mike Santi
Scheduled completion: June 2017

The current design procedures used to estimate liquefaction-induced lateral spreading in bridge-foundation-soil systems are often overly conservative. A modified design procedure has been developed as a means to more appropriately consider relevant factors, and it has been shown to be effective at reducing some of the excessive conservatism associated with more simplified design approaches. However, only limited testing and analysis have been conducted to verify and benchmark the relative safety of the resulting design solutions for a range of bridges, foundations, and soil conditions. Before local agencies adopt this modified design approach, it is important to verify the safety of the resulting bridge and foundation designs for conditions typical in the Northwest, and to develop a database and benchmarking framework useful for future evaluations. Once the modified lateral spreading design approach has been verified, it will lead not only to potential cost savings in the design and construction of future bridges, but it will also increase public safety by reducing the potential for bridge collapse and minimizing the time associated with lost bridge service immediately following lateral spreading caused by an earthquake.

Principal Investigator: Balasingam Muhunthan, Civil and Environmental Engineering, WSU
Sponsor: PacTrans
Scheduled completion: January 2018

Fascia walls are structural earth retaining components for soldier pile and soil nail walls, and they are traditionally constructed with cast-in-place (CIP) concrete.  In recent years, some state DOTs have begun to replace the CIP concrete with shotcrete for wall fascias.  This method of construction is attractive because of its potential for saving cost and construction time. However, it also has numerous potential drawbacks that raise durability concerns. Currently, the state of knowledge regarding the proper shotcrete mix design, construction, curing practices, quality assurance, durability performance, condition assessment, maintenance, and repair/rehabilitation is scattered in published domain or undocumented. In addition, most of the evaluation and test methods commonly developed for concrete cannot be directly applied or are not suitable for characterization of shotcrete.  Therefore, the goal of this project is to provide a thorough review of the state of knowledge about shotcrete to ensure its proper use for wall fascia and slope stabilization. In particular, this project will investigate the adequacy of shotcrete consolidation, permeability, early age shrinkage and associated cracking, potential for early rebar corrosion and long-term durability.  With the increasing desire for highway agencies to use shotcrete for accelerated construction and rapid renewal, such a synthesis will be a useful resource to help them achieve the best structure quality and durability.

Principal Investigator: Pizhong Qiao, Civil and Environmental Engineering, WSU
Sponsor: WSDOT
WSDOT Project Manager: Lu Saechao
Scheduled completion: June 2017

Roadway maintenance agencies are continually challenged in winter to provide a high level of service and improve safety and mobility in a cost-effective manner, and to that end, they strive to use the most recent advances in the application of maintenance materials, equipment, and sensor technologies, as well as decision support systems. In support of that objective, the goal of this research is to create a synthesis of best management practices for deicing application rates, material application methodologies, and material usage, including chloride brines applied directly or as additives to abrasives and rock salts. To achieve this goal, this project is gathering and analyzing relevant existing information, with a focus on the best application equipment, methodologies, and typical application rates of chemical products commonly used by highway agencies during their anti-icing, deicing, and prewetting operations. The information will be synthesized to produce updated guidelines for material application rates as a function of road-weather scenarios in the field. Such best practices are expected to improve the effectiveness and efficiency of winter operations, to optimize material usage, and to reduce associated annual spending, as well as corrosion and environmental impacts.

Principal Investigator: Xianming Shi, Civil and Environmental Engineering, WSU
Sponsor: Minnesota DOT
Scheduled completion: September 2018

For certain highway segments in northern climates, snow drifting can create hazardous driving conditions or necessitate nearly continuous plowing, excessive use of chemicals, or road closures. An emerging alternative to wooden, plastic, or metal snow fences are living snow fences (LSF)—trees, shrubs, and prairie grasses strategically planted to act as windbreaks. These not only provide a longer-lasting, low-maintenance, and cost-effective solution to snow drifting but they also sequester carbon, enhance wildlife habitat, improve erosion control and water quality, and reduce flooding. Unfortunately, field and laboratory testing approaches are impractical for LSF design studies because of the high costs and effort required to reproduce their wide range of possible conditions, including different plant species, topography, prevailing wind conditions, and roadway geometry. To develop recommendations on design and placement of living snow fences, this study is developing 2-D and 3-D computational fluid dynamics models to incorporate aerodynamic transient snowdrift development (creep, saltation, and suspension) and computer-aided design and drafting 3-D drawings to enable site-specific analysis. Once the model has been field tested and completed, it will be used to assess the effects of freeway interchanges and roadway sections on the performance of snow storage and to identify critical design parameters affecting the performance of LSFs.

Principal Investigators:
Xianming Shi, Civil and Environmental Engineering, WSU
John Petrie, Civil and Environmental Engineering, WSU

Sponsor: Illinois Center for Transportation
Scheduled completion: December 2020

Previously, the Seattle Obesity Study generated objective measures of the built environment, diet quality, and health outcomes by tracking 500 King County, Washington, participants asked to carry global positioning system devices for a week. The projects’ findings covered the cost of food and people’s choice of supermarket, the absence of food deserts in King County, the clustering of people by weight status and socioeconomic status, and a comparison of food shopping behaviors in Seattle and Paris, France. This new phase of the project is seeking to explain why obesity rates are closely linked to both individual and area socioeconomic status, whereas weight change measured over 12 months is not.  By looking at the built environment and its relationships to food shopping, diet quality, obesity, and related physical activity for residents, the project should help public decision-makers in creating healthier environments.

Principal Investigators:
Anne Vernez Moudon, Urban Design and Planning, UW
Adam Drewnowski, Epidemiology, UW

Sponsors:
National Institutes of Health
National Institute of Diabetes and Digestive and Kidney Diseases

Scheduled completion: July 2020

This study is investigating the role of local businesses in reducing cardiovascular disease and related disparities for an aging population.  The study will link longitudinal geographic data and residential histories acquired through Lexis Nexis with characteristics of built environments across decades.  UW researchers are leading the effort to ensure that available residential address data are cleaned and geocoded with minimal missing information.

Principal Investigator: Philip M. Hurvitz, Urban Design and Planning, UW

Sponsors:
National Institutes of Health
Columbia University

Columbia University Technical Monitor: Gina Lovasi
Scheduled completion: April 2017

This project is evaluating a truck dispatch optimization system that Productivity Apex, Inc is developing under FHWA guidance. The freight advanced traveler information system (FRATIS) system is being deployed in Dallas, Texas, in association with major reconstruction work on I-35, a corridor that represents 11 of the 100 most congested roadways in Texas. The project involves the development of a geographic information data system that tracks truck movements and provides a variety of performance metrics on the basis of those movements. Successful demonstration of FRATIS on a statewide freeway corridor that contains significant work zone activity and congestion will highlight to the nation’s over-the-road trucking companies the benefits of FRATIS applications.

Principal Investigator: Mark E. Hallenbeck, Washington State Transportation Center, UW

Sponsors:
FHWA
Cambridge Systematics

Scheduled completion: June 2018

WSDOT currently does not use precast, decked bridge members, such as deck bulb tees, on major highways, largely because bridges built with them on smaller roadways have developed cracks along the longitudinal joints.  Because the use of decked members would allow faster on-site construction, this cooperative UW/WSU project is seeking to develop a transverse connection between deck bulb tee flanges by using ultra-high-performance concrete (UHPC) to provide full continuity across the joint. Researchers at WSU developed a UHPC mixture that depends on locally sourced materials, thereby avoiding the high costs of the proprietary material, and working to establish its critical properties, particularly bond and durability. UW researchers are evaluating first subassemblies and then complete joints for their stiffness and strength in bending. The benefits of the work to WSDOT will be the ability to construct durable bridge decks with precast, decked members, thereby avoiding the need to form, reinforce, and cast the deck on site.  This will result in considerable time and cost savings.

Principal Investigators:
John F. Stanton, Civil and Environmental Engineering, UW
Pizhong Qiao, Civil and Environmental Engineering, WSU

Sponsor: WSDOT
WSDOT Technical Monitor: Bijan Khaleghi
WSDOT Project Manager: Lu Saechao
Scheduled completion: June 2017