August 28th, 2012

SEISMIC SAFETY

No Comments, Preserve Infrastructure, by Catherine Higgins.

The Utah Seismic Safety Commission brings a diverse group of experts together to reduce earthquake risk.

Joshua Sletten

The fifteen member board was created to assess Utah’s earthquake risks, to promote awareness and to support state and local government efforts to protect public safety during and after a quake.

“The commission provides an integrated picture of seismic concerns for the whole community,” says Josh Sletten, UDOT Structures Design Manager and USSC Commissioner. Sletten represents the transportation point of view as the commission plans and implements ways to improve earthquake readiness in Utah. While the commissions efforts are not transportation centered, Utah’s transportation system is an important part of the overall picture since the transportation system is a vital part of response and recovery after a quake.

Keeping roads open

Two of UDOT’s key roles are to have an emergency response plan in place and to identify key routes that will remain operational after a major earth quake. The emergency response plan uses workers that are nearest the scene of the emergency to quickly inspect and identify the risk to the traveling public on structures and roadways. Next, engineers will strategically visit locations, starting with the most vulnerable areas first, to properly address affected structures.

Identifying key routes that provide access to hospitals, shelters and emergency services is an ongoing process as the community changes. Once key routes are identified, UDOT engineers take all aspects of the roadway into account. Structures especially are of great concern and UDOT builds structures like bridges and overpasses to withstand major quakes.

UDOT bridges are designed and constructed to AASHTO design standards which account for hazard events such as earthquakes.  Many of the bridges on I-15 through the Wasatch Front have been rebuilt in the last 15 years. While UDOT does not anticipate extensive damage to the transportation system, some damage will occur. And, uncertainty exists when it comes to events, such as power outages and how those events will affect the transportation system.

Risk ID

The USSC works closely with the United States Geological Survey on ways to identify potential risk during a quake. The USGS has developed a software program called ShakeCast to generate estimated damage data for structures like buildings and bridges. In an actual seismic event, ShakeCast can also be used to send notification to infrastructure owners indicating the level of shaking and estimated damage from the quake. For UDOT, using ShakeCast means that we know the level of damage that is likely to occur, according to Sletten.

When it comes to seismic safety, planning is critical. The USSC issued a strategic plan in 1995. Since that time, 27 of the 35 critical objectives have been met. By participating in the USSC, UDOT and other critical infrastructure owners and emergency service providers can work together to ensure that Utah citizens are as safe as possible during and after a major earthquake.

August 24th, 2012

BLOG SURVEY

No Comments, Optimize Mobility, Preserve Infrastructure, by Catherine Higgins.

The UDOT Blog is intended to inform a transportation audience.

The UDOT Blog debut was April 21, 2010, and since then, 371 articles have been posted. The topics range from safety to geo-tech, and the intended audience is UDOT employees, private sector partners and members of the general public.

The blog is designed to allow readers to share ideas and find out about programs, projects and practices at UDOT. The format is based in part on an initial survey of UDOT employees. A total of 803 employees answered the survey, and provided feedback that became guidance for the blog.

The UDOT Communications Office invites you to take another survey so the blog can be improved.

August 23rd, 2012

EROSION REPAIR

1 Comment, Preserve Infrastructure, by Catherine Higgins.

UDOT is just one of the agencies working to repair erosion that occurred during a flash flood in Huntington Canyon in the Manti-La Sal National Forest.

UDOT is also in the process of rebuilding the road in two areas where water flow washed out embankment and shoulder.

A rain storm that occurred on August 1 caused a flash flood that washed trees, soil and rocks from the canyon walls into cut-ditches and culverts and onto SR-31. The flooding event was made worse by the Seeley Fire that occurred in the area before the flood. Because much of the vegetation was burned away, the runoff washed debris down the canyon. “It was an incredible flood,” says Jim Chandler, UDOT Region Four Area Engineer.

UDOT crews made a herculean effort to clear and open the road during the week after the flood, according to Chandler. But without the natural vegetation on the slopes, rain or snow melt in the spring could cause more erosion in Huntington Canyon. “It damaged more than just a highway,” says Chandler.

The flood also took its toll on the natural environment explains Darren Olsen, U.S. Forest Service District Ranger. The flash flood “scoured out the natural drainage areas” including seasonal stream beds that carry spring runoff or flooding to Huntington Creek and out of the canyon. Ash from the fire washed into the streams and killed fish and downstream agricultural users are dealing with sediment that clogs irrigation systems.

The most significant fire damage and erosion occurred on north-facing slopes where conifers typically grow. Many of those trees had been killed by beetles, and that dry wood provided fuel for the fire.

Olsen is helping to plan some mitigation in targeted areas to prevent similar flash floods in the future. “Already Mother Nature is doing a good job at re-vegetating the south facing slopes” where new growth is coming in. The USFS is planning to place wood mulch on 540 acres of area on steep slopes. The mulch will slow down runoff until vegetation can be reestablished. Reseeding areas of the Seeley Fire will be flown in to help get plants established.  This reseeding effort aims at encouraging “quick plant growth that will capture the rain.”

Olsen says that between Mother Nature and the USFS efforts, two to five years is the expected time for vegetation to fill in the burned areas. He says one concern is spring weather; a cold spell followed by warm weather could cause heavy runoff from snow melt.

August 22nd, 2012

RESTORING SR-31

1 Comment, Uncategorized, by Catherine Higgins.

UDOT crews are working hard to clear debris and reestablish drainage in the area of the Seeley Fire where a flash flood stripped the area of trees, rocks and soil and shut down SR-31.

The flooding occurred during a rain storm on August 1 in the Manti-La Sal National Forest in southeastern Utah. The storm dropped about one and a quarter inch of rain in a half hour. Although similar storms are fairly common in the forest, this storm “was enhanced by the fire,” says Jim Chandler, UDOT Region Four Area Engineer.

“When fires go through the forest, they can make the soil hydrophobic,” explains Chandler. The temporary soil condition can occur when burned material takes up the empty pore spaces where water would normally seep in. In just a short space of time, the runoff “hit rocks and trees and brought them down the canyon,” says Chandler. “The fire just created the perfect condition to wash everything away.”

And much of the debris ended up on SR-31. Chandler says in one spot, rock, soil and trees were piled over 6 feet high. UDOT crews from the Huntington, Wellington, Colton, Emery, Mt. Pleasant and Gunnison Maintenance Stations “worked hard day after day moving a lot of material and trees,” says Chandler. Given that the road was open one week later, their effort was “quite amazing.”

The run-off that occurred during the flash flood also caused scour in stream beds and in other natural run-off areas, according to Darren Olsen, U.S. Forest Service District Ranger. Olsen says the USFS is planning some mitigation to prevent similar flash floods in the future.

Because of the volume of debris flow, the most challenging part of the erosion repair effort for UDOTis cleaning out and restoring culverts and cut ditches “so that the water that does reach the road can pass through with minimal damage to the road”  says Daryl Friant, UDOT District Engineer.  During a storm, runoff flows along the road in cut ditches and the under the road through culverts.

UDOT is also in the process of rebuilding the road in two areas where water flow washed out embankment and shoulder and one area where water flowed over the road and caused pavement to break up.

Work will continue through fall, according to Chandler. “They’ll be out there until the snow flies,” getting drainage established in order to make the area safe for the traveling public.

Created with Admarket’s flickrSLiDR.

August 21st, 2012

BETTER JOINTS

1 Comment, Preserve Infrastructure, by Catherine Higgins.

Better longitudinal joints in asphalt pavement mean longer pavement life.

When not compacted adequately, longitudinal joints can be destined for failure and can threaten the whole pavement system.

A longitudinal joint in Hot Mix Asphalt pavement is formed when a new batch of asphalt is placed adjacent to existing pavement. Because of temperature and plasticity differences, sometimes the newer and older pavements fail to bond, and the joint has significantly less density than the rest of the pavement.

A long  joint that is not compacted adequately can be “the weak link in the pavement,” explains Kevin VanFrank, UDOT Engineer for Asphalt Materials. “What you have is a seam in the mat that’s difficult to keep water out of.” Because the joint is permeable, water seeps in, the pavement ravels and loses material. Soon that damage “starts to migrate into the balance of the system…you can lose the entire pavement system.”

Under the best of circumstances, joint is typically less compacted than the mat. Van Frank says that a small difference of two to three percent can be acceptable.

HMA mix designs also play a role in the compaction at the joint. “As we attack rutting, we end up with mats that are more difficult to compact and lose the compaction in the joints without making special effort.”

The best solution to achieving good compaction at the long joint is to use echelon pavement placement and install two widths of pavement at the same time. UDOT’s specification states that echelon paving is preferred; however, the method is not always practical because lane closures are required. When echelon paving is not practical, other techniques should be employed.

A survey of each of the fifty states conducted by the Federal Highway Association shows that long joint health is a big concern among departments of transportation. Half of the states were found to be not satisfied with the overall performance of long joints, however, not all states have specifications in place that seek to achieve good compaction.

Some states had density specifications in place and others defined accepted construction techniques. But, even though the survey found an array of best practices being employed, a definitive solution was not identified.

In an effort to find the best solution to achieve good joint compaction, UDOT will select projects and look to the paving industry to identify good construction techniques. “Our intention is to implement the compaction of the long joint to a standard value.”

“We’re going to define an outcome and let industry meet the outcome,” says VanFrank. “We have seen techniques used this year that make joint density approach mat density.” Van Frank believes that by using UDOT will select appropriate projects to be built next year and allow contractors to lead the way UDOT will be able to identify the best solutions to ensuring better joints.

August 16th, 2012

THANKS FOR THE MEMORIES

1 Comment, Optimize Mobility, Preserve Infrastructure, by Catherine Higgins.

To all those who sent in photos for the Faces in Transportation – Thanks!

Faces in Transportation is an annual competition that solicits photos that show the people who build, maintain and use our nation’s transportation system. UDOT employees sent in many great photos and two were selected by Director John Njord and Deputy Director Carlos Braceras.

Prizes of the contest include awards that go to the entering agency: first Prize, $500; People’s Choice Prize, $500; Three Prizes in each of three categories, $125 each.

Voting for the People’s Choice award is open. Follow this link to see UDOT’s photos and vote!


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August 15th, 2012

UAC AT UDOT

No Comments, Preserve Infrastructure, by Catherine Higgins.

AggieAir is a Utah State University service that uses small, unmanned aircraft to provide aerial images to a variety of customers, including UDOT.

Located at the Utah Water Research Laboratory,  the AggieAir  photo collection method was first developed in response to agricultural needs, specifically to evaluate the effectiveness of irrigation practices.

Aerial images for agricultural needs can also be met by using satellites or manned aircraft; both methods have limitations, however. Satellite images often have course resolution, cloud cover can obscure the view of the area being photographed and a delay of up to one month in acquiring images can make the information outdated. Manned aircraft services are expensive.

Small plane services, like AggieAir offer a flexible platform that can provide high quality images for a variety of needs quickly and easily. According to AggieAir Research Engineer Austin Johnson, “UAVs are popping up everywhere” for that reason. He visited UDOT recently and and gave an overview of AggieAir, including some UDOT projects that have use the service to acquire images.

AggieAir collects common RGB photos Near Infered as well as thermal imagery and uses software similar to GIS applications to process the image data. While in flight, the planes take photos about every four seconds. The images are then combined to make a Geo-rectified mosaic image of the ground surface and features. The cameras can also be mounted on a vehicle for gathering ground level images.

The planes are small, lightweight and launched into flight using a staked bungee cord. There is no landing gear, so touchdown can be bumpy. The planes are made of durable Styrofoam that can be taped up after a rough landing.

UDOT  has used the service to get aerial images of the Southern Parkway project and the wetland area near Utah Lake. Other possible applications for the platform include taking an inventory of freeway structures and signs, before and after construction images, cataloging historic occurrences of flood or wetland areas, tracking erosion on embankment slopes, identifying invasive plant species and evaluating treatment plans for eliminating those species.

August 14th, 2012

2013 MAP

No Comments, Optimize Mobility, by Catherine Higgins.

UDOT is collecting information for the 2013 Official Utah State Highway Map.

Lisa Holgreen, UDOT Communications Assistant sends out maps almost daily.

UDOT and the Utah Office of Tourism partner to produces the state’s Official State Highway Map, and the process to re-do the new map is underway. Updating the map takes into account input from UDOT employees, county road supervisors and state and federal agency representatives. Effort is underway now to contact people who may have suggestions for improving the new map.

While UDOT cartographers make the map’s features accurate, the Utah Office of Tourism makes it beautiful. Clarkson Creative, a local graphic arts company will design a layout for the new map that emphasizes Utah’s scenic attractions.

The map is used by citizens, visitors to the state and school children from across the nation who need information for school projects. Lisa Holgreen, UDOT Communications Assistant sends out maps almost daily. Every year, UDOT sends around six hundred maps to individuals and more to visitor centers across the state. If Holgreen gets a request from a visitor center, she can often send more than one thousand maps in a day. The Utah Office of Tourism also mails maps on request and distributes maps through visitor centers.

A digital version of the map is available online on UDOT’s website. To make suggestions for changes on the new map, email your comments to statemap@utah.gov.

August 13th, 2012

IC DEMO

1 Comment, Optimize Mobility, by Catherine Higgins.

UDOT recently hosted an FHWA demonstration of Intelligent Compaction.

Intelligent Compaction uses GPS to determine the location and number of passes and sensors to determine the temperature and stiffness of asphalt pavement. The technology may eventually take the guess-work out of compacting pavement.

US 89 and SR 180 in UDOT Region Three is the first of nine projects locations from across the country to employ and evaluate Intelligent Compaction. The data collected and experience gained by studying IC will eventually determine if the sophisticated construction method effectively takes the guess-work out of compacting asphalt pavement.

IC systems are similar to regular asphalt pavement compactors but equipped with GPS to determine the location and number of passes and sensors to determine the temperature and stiffness of the pavement. As the compactor makes passes over the newly installed asphalt, stiffness measurements are integrated with the GPS information on a display that gives the operator a comprehensive near real-time picture of the compaction process.

The system creates an animated, color-coded online map so the compaction process can be monitored. The animation can also be played back for review.

Although the process measures pavement stiffness, the intent of the project is to correlate stiffness with pavement density, which is critical when it comes to longevity of the pavement, explains Lee Gallivan, Asphalt Pavement Engineer with FHWA. “Compaction is really the central part of the performance of the pavement.”

“You can have a real great mix design that meets all the Superpave requirements,” explains Gallivan, but with poor compaction, the pavement will not achieve appropriate density and meet the test of time. Conversely, a poor or mediocre mix design can be compacted well, and that pavement may last a long time.  Extending the life of pavement “is where the public gets its money’s worth.”

Over the next two years, FHWA will sponsor IC demonstration projects in diverse parts of the country. The IC measurements will be correlated to nuclear gauge or coring density tests. The data collected from the geographically disparate projects will provide information about different mix designs, environments, substrates and traffic levels. Eventually, IC could become an accepted method for quality-control and quality-assurance for contractors and departments of transportation.

The Federal Highways Administration is sponsoring demonstrations of a new technology that uses radar to analyze pavement.

GPR technology uses radar to create a cross sectional analysis of the pavement.

The new technology can help determine the remaining service life of pavement without using invasive means. Testing is necessary to find out what conditions are causing pavement deterioration, and then to determine the right course of action to take to preserve or replace the pavement.

Typically, engineers determine the remaining service life pavement by drilling core samples. Coring pavement takes time and resources to extract , transport and then test the pavement. Coring is also an inconvenience for the traveling public since lane closures are required for the work to take place.

Ground Penetrating Radar can provide a close and detailed look at pavement without the time, expense lane closures required by coring.

GPR technology uses radar to create a cross sectional analysis of the pavement under the surface. The equipment is mounted on a regular vehicle that can move with traffic, so no lane closures are required. While coring gives snap-shot looks at pavement condition.

In one sweep, GPR can collect enough information to have a comprehensive view of the pavement, including density, material variation, degradation due to stripping or other factors, and thickness. The data collection method works on concrete or asphalt and is “a better way to diagnose the problem,” according to Tom Yu, Senior Pavement Design Engineer with FHWA.

Although GPR is a great diagnosis tool for pavements that need rehabilitation, Yu sees other opportunities as well. “For me, the most promising area is construction [quality and assurance] testing.” Yu visited UDOT Region Three recently with a GPR equipped van and spoke at an Intelligent Compaction Demonstration. He will take the van on the road to collect data so he can demonstrate the usefulness of the new technology. “It needs to show its own value” before the pavement data collection method is widely adopted.