| Abstract XXVI |
 |
|
|
 |
| Seismic Vulnerability |
|
Seimic Vulnerability of Oregon State Highway Bridges: Mitigation Strategies to Reduce Major Mobility
The Oregon Department of Transportation and Portland State University evaluated the seismic vulnerability of state highway bridges in western Oregon. The study used a computer program called REDARS2 that simulated the damage to bridges within a transportation network. It predicted ground motions for a specific location and magnitude of earthquake, resulting bridge damage and the cost of the damage, as well as the cost to the public for traffic delays due to detours around damaged bridges. Estimated damage and delay costs were presented for major highways in the region.
|
|
|
| Safety Investment Program |
|
Evaluating the Effectiveness of the Safety Investment Program (SIP) Policies for Oregon
The Safety Investment Program (SIP) was originally called the Statewide Transportation Improvement Program - Safety Investment Program (STIP-SIP). The concept of the program was first discussed in October 1997 and the program was adopted by the Oregon Transportation Commission in August 1998. The concept for the program grew out of a cost-effective approach to pavement preservation projects that set out to maximize the impact of money spent on highway safety, based on crash reduction factors. Safety projects were to be selected based on high crash locations as identified by the Safety Priority Index System (SPIS) and SIP Category ratings of five-mile sections. This research evaluated the SIP Policy from the perspective of: 1) an overall program for safety improvement projects, 2) a guiding policy when safety improvements are planned as part of other project work, and 3) a component integrated with the highway design procedures for resurfacing, restoration, or rehabilitation (3R) projects. The research included two levels of evaluation; the first evaluation was done as part of the systemic evaluation, while the second was a project-level evaluation. The systematic evaluation revealed that, in general, projects where safety funds were used resulted in a net decrease in total crashes as well as severe and fatal crashes; however, these benefits were not realized for all locations or all work types. The detailed review of the 24 mixed safety-preservation projects highlighted some of the challenges of successfully implementing the SIP Policy. It was clear that the SIP Policy has not been applied consistently to mixed projects. In particular, the variety of design and, to a lesser extent, the funding eligibility scores, highlight the variety of policy interpretations. The project-level evaluation concluded that the most important project element to improve safety performance was the specific identification of a safety problem. Recommendations were made on improved documentation procedures at the project level as well as strategies to improve overall policy compliance.
|
|
|
| Effectiveness of Cathodic Protection |
|
Effectiveness of Cathodic Protection
The report provides a summary of Oregon’s experience with cathodic protection of coastal reinforced concrete bridges.
Thermal-sprayed anodes, foil anodes with a conductive adhesive, and carbon painted anodes are effective in distributing current to the steel reinforcement in concrete bridges. A resistive layer develops at the anode-concrete interface with increasing electrochemical age, thereby increasing anode polarization. In impressed current cathodic protection (ICCP) systems this is reflected in a higher circuit resistance. In sacrificial anode cathodic protection (SACP) systems it results in lower current output. Periodic wetting of the anode by rain, fog, and dew is an important factor in reducing anode polarization.
Catalyzed thermal-sprayed titanium anodes under ICCP service develop no significant anode polarization with electrochemical age. They perform well in both low and high humidity environments, and exhibit stable long-term performance.
Humectants based on LiNO3 and LiBr promote more effective performance of new and aged anodes in CP systems than untreated anodes. In SACP tests, LiBr was more effective
than LiNO3. In accelerated ICCP, LiNO3 was more effective than LiBr.
In SACP service, zinc hydrogel anodes produce a stable protection current sufficient to protect reinforcing bar from corrosion. There was practically no effect of changing moisture conditions on current production and no evidence of aging effects in an Oregon DOT field trial.
|
|
|
| Digital Image Rectification Tool |
|
Digital Image Rectification Tool for Metrification of Gusset Plate Connections in Steel Truss Bridge
A method was developed to obtain dimensional data from photographs for analyzing steel truss gusset plate connections. The method relies on a software application to correct photographic distortion and to scale the photographs for analysis. The approach enables rapid and accurate collection of dimensional measurements compared to traditional methods. Users can quickly create AutoCAD drawings by collecting dimensional information about the gusset plates from the photographs. The rectified photographs provide a record of field conditions that can be compared with subsequent field inspection results to help identify and quantify long term changes in visual characteristics. The implementation procedure is straightforward and does not require specialized
knowledge of photogrammetry. It can be practically employed under field conditions using current technology and personnel, and it reduces the likelihood of data entry errors. Dimensional measurements from the method provide results that are as good conventional field measurements and are within tolerances that most engineers would find reasonable for gusset plate connection capacity evaluations.
|
|
|
| Blowing Dust Alarm |
|
An Experimental Blowing Dust Alarm System for Highways
Blowing dust storms pose a visibility hazard to highway motorists. An experimental alarm which senses electrification of a metal antenna by blowing dust particles is described. The metal antenna can be an ordinary radio whip antenna or an insulated top strand of barbed-wire right of way fence to monitor a greater area. The sensor responded favorably under conditions of half mile visibility and 20 mph winds. Field tests were conducted by telemetry to an office microcomputer.
Dust related radio noise which blanks out broadcast reception is attributed to electrification of metallic objects and subsequent corona or spark discharge.
An experimental acoustic sensor for flowing sand is also described along with comment on application of an ionization chamber to detect motionless dust.
|
|
|
| Chip Seal Test: OR Rt 22 |
|
Polymer Modified Chip Seal Test: Oregon Route 22
This report describes the construction and performance of ten pavement chip seals applied on June 17 - 18, 1987 using nine different emulsified asphalt binders. Seven of these asphalts were modified with different polymers, and the remaining two were conventional. The polymers used in the emulsions were Styrene Butadiene, Styrene Butadiene Synthetic Rubber, Styrene Butadiene Styrene Block Co-Polymer, Styrene Malam, Neoprene Latex Synthetic Rubber Co-Polymer, Ethylene Vinyl Acetate or Rubber Styrene Butadiene Styrene.
The chip seals were applied in a single pass using conventional construction techniques. Other than the addition of a modifier in each emulsified asphalt, no special procedures were required or used.
The chip seals were rated for overall performance based on both initial chip retention and their condition after two years of service. Three sections containing conventional asphalt and one section with polymerized asphalt were rated in a poor condition after two years. The low ratings may be related to conditions during construction as well as materials properties.
|
|
|
| Sweet Home Survey |
|
Sweet Home Business and Customer Survey
The results of the telephone survey are provided in this report. The survey was conducted by the University of Oregon’s Survey Research Laboratory in mid-October, 1999 to determine the impact of the highway construction on access to businesses and to judge the effectiveness of the “temporary business access” signs. The survey includes a customer survey of people living in Sweet Home and a survey of businesses located along Highway 20 in Sweet Home.
|
|
|
| Peer Exchange 2001 |
|
Research Management Peer Exchange 2001
The Oregon Department of Transportation hosted a research management peer exchange August 20-24, 2001. The purpose of a peer exchange is to give research managers from state departments of transportation and the federal government a means to improve the quality and effectiveness of their research processes, both for the host department and the visiting research managers.
|
|
|
| Armorform Articulating Block Mat |
|
Armorform Articulating Block Mat Erosion Control System
ARMORFORM® Articulating Block Mat (ABM) was used as part of a bridge replacement project at the Salmon Creek Bridge abutments in the summer of 1991. ABM was selected to replace riprap which was continually being undermined by the erosion of the streambed. ABM was selected due to its ability to maintain its structure (articulate) and withstand erosion. The original design requiring the mat to be keyed into the bank could not be constructed according to the manufacturer due to product limitations. Therefore, contrary to the original design, the flanks of the mat were not embedded into the bank to protect against undermining from bank erosion.
The ABM did work well during the flood event in February of 1996. Although the northwest corner was undermined, the blockmat articulated and changed slope to partially fit the void. Because the bank erosion stopped near the edge, it appears that the ABM also retards embankment erosion. However, the gap was not filled completely which allowed the rushing water to flank the mat increasing the damage. Downstream, some of the blocks were torn away from the mat while others were uncovered in the toe trench. Since the riprap placed by maintenance to retard the erosion is end dumped rather than keyed into the channel bottom and bank, the stream will probably continue to flank the ABM.
Future designs subject to similar flow conditions should consider keying the upstream edge 10 ft (3 m) into the bank and burying the toe 8 ft (2.4 m) into the channel bottom. In addition, the design should include riprap to protect the flanks of the mat. The ideal situation would be to construct the mat as designed with the fan shaped ends. The ABM appears to be most suited for active streambeds susceptible to erosions with slopes steeper than 1.5H:1V (steeper than is reasonable to place riprap).
Future designs should also consider the configuration of the ABM blocks. Consideration should be given to configuring the blocks so that there is no vertical alignment offset versus staggering the blocks. Aligned rows of blocks would allow articulation in all directions.
|
|
|
| Geotextile Reinforced Bridge |
|
Geotextile Reinforced Bridge Approach Embankment
In an attempt to reduce the discontinuity between the bridge and the roadway due to the settlement and/or consolidation of the approach embankment, an experimental construction method was tested on the Lost River Bridge in Klamath County. The method consisted of combining soil in six 1' lifts, interlaced with the geotextile reinforcement. This method was designed to reduce the settlement of the newly placed fill, thus reducing the discontinuity.
The Lost River Bridge was widened by 10'3" on each side. The additional width of the bridge required short narrow sliver fills at all four corners. The geotextile reinforcement was only used in the sliver fills and did not run the whole width of the road-to-bridge transition. The material was easy to work with considering the small size of the project. Although the original plans called for the geotextile reinforcement to be used at two of the four corners, to allow for a control lane in the northbound direction, it was used at all four corners.
A settlement plate was installed at all fill location before the first lift was put down to measure the settlement of the original soil under the new fill. The settlement of the new fill will be found by subtracting the original settlement soil from the total fill settlement.
The construction of the sliver fills went well. The soil used for the fills was native soil from the job site. It consisted of about four different types of soil, and was granular in nature. Compaction requirements were met by placing each lift with 6 inches of loose soil.
The construction of the new sliver fills gave a good ride immediately after construction. There were no bumps at the road-to-bridge transition.
|
|
|
| Polymer Modified Asphalt Concrete |
|
Field Test of Polymer Modified Asphalt Concrete: Murphy Road to Lave Butte Section
This report covers the construciton of open-graded asphalt concrete test sections using one conventional and three different polymerized binders. The binders were: 1) Chevron's conventional AC-20 as a control, 2) Elf Aquitane's Styrelf with SB polymer, 3) Asphalt Supply and Service's AC-20R with SBS polymer, and 4) Chevron's CA(P)-1 with DuPont's Elvan (EVA) polymer.
This report also includes a summary of: pre-construction conditions, pavement design, test results and methods, the condition of the road just after construction, and cost data.
Satisfactory pavements were made with all of the binders. There were no major design or construction related problems. Minor problems included: 1) Styrelf and AC-20R tended to migrate downward through the mix, 2) AC-20R, and to a lesser degree, Styrelf left deposits on the surface of transport equipment, 3) all polymerized binders presented some problems with mix sample collection and binder extraction. None of these miner problems slowed the progress of the paving, and most were solved with innovations in either equipment or technique.
|
|
|
| Recycled Plastics |
|
Recycled Plastics in Highway Construction and Maintenance
Oregon Senate Bill 66 directed the Oregon Department of Transportation to conduct a research project to evaluate the use of recycled plastic products and composite materials containing recycled plastic in construction and maintenance. This report documents the installation throughout the state of snow poles, sign supports, fence posts, and a sound wall.
Recycled plastic materials may be more difficult to obtain than standard wood products. Upfront material and shipping costs are more expensive than comparable wood products. Handling of recycled plastic materials is similar to handling treated wood products except recycled plastic materials are heavier. Recycled materials may be more readily recyclable than treated wood products.
Recycled snow poles were easier to install than standard snow poles. Recycled plastic sign supports, fence posts, and sound wall materials, in general, were more difficult to install.
Recommendations from this study include the following:
1. Additional recycled plastic material installations should be encouraged to obtain more information regarding the constructability of recycled plastic materials;
2. Recycled plastic fence post for installations in areas with dense soils should be ordered with a point at one end;
3. Recycled fence post should be installed by pushing with steady pressure rather than driven with repeated blows; and
4. Recycled plastic boards used for sound wall facing should have tongue and groove joints to insure proper interlocking and to reduce the amount of blowing.
|
|
|
| Vegetated Riprap |
|
The Role of Vegetated Riprap in Highway Applications Final Report
Riprap is the most commonly used material to protect bridge abutments and highway embankments adjacent to bridge abutments from erosion. Removal of the riparian vegetation in preparation for riprap construction can lead to environmental impacts such as increased water temperature and reduction of the quality of stream habitat. A method that is commonly recommended as a mitigation measure is to plant willows in the riprap to reestablish the riparian vegetation. There are engineering concerns that the willows will reduce the stability and flexibility of the riprap and eventually cause the riprap to fail. This report addresses the review of literature on the subject.
|
|
| |
|
|
