The poster session contains two papers related to roadside issues. The first paper covers roadside slope failures. As part of a broader study on roadside slope repair measures, the paper intended to identify “complementary” slope repair measures and their recommended practices to sidestep recurring failures. The findings of this study show that the application of simple slope repair methods can reduce roadside slope failures and save tax payer dollars. The second paper involves LiDAR to mapping the profile of the roadside ditch. Error propagation models and previous field test suggest this technology can map the vertical profile of a ditch with an accuracy of 2-3 centimeters at distances up to 30 meters from the mobile mapping vehicle.
Complementary Roadside Slope Repair Measures to Avoid Recurring Failures: The Case of Texas
Seyed Ehsan Zahed (firstname.lastname@example.org), VRX, Inc.Show Abstract
Bahram Abediniangerabi, University of Texas, Arlington
Mohsen Shahandashti, University of Texas, Arlington
Roadside slope failures are a chronic issue along the United States roads. Texas with the most extensive network of highways in the U.S. has been prone to many roadside slope failures due to the extreme weather and soil conditions. Texas Department of Transportation (TxDOT) spends millions of dollars every year to repair such failures and maintain roadside conditions. Despite all the technological advancements in slope repair methods, many repaired slopes are still showing recurring failures. There is a strong consensus among the practitioners that a combination of different slope repair measures would increase the service life of the repaired slopes. This paper, as part of a broader study on roadside slope repair measures, intends to identify “complementary” slope repair measures and their recommended practices to sidestep recurring failures. A research approach including review of the literature, fact-finding survey, and interview of subject matter experts from all 25 TxDOT districts, and study of recent and successful slope repair cases is used to achieve the research objectives. Vegetation, water management measures, benching and stepping, and additives are identified as general complementary methods that improve the performance of other repair measures. Moreover, vegetation and water management measures are identified as “preventive” methods that their application to the existing slopes would enhance their stability conditions. The findings of this study show that the application of simple and well-known slope repair methods could mitigate the issue of roadside slope failures and save transportation agencies such as TxDOT, millions of dollars every year.
Mobile LiDAR Mapping of Roadside Ditches for Drainage Analysis
Yi chun Lin, Purdue UniversityShow Abstract
Darcy Bullock, Purdue University
Ayman Habib, Purdue University
Maintenance of roadside ditches is important to avoid localized flooding and premature failure of pavements. Scheduling effectively preventative maintenance requires reasonably detailed mapping of the ditch profile to identify areas requiring excavation of long term sediment accumulations. High-resolution, high-quality point clouds collected by mobile mapping systems (MMS) provide an opportunity for effective monitoring of roadside ditches and perform hydrological analyses. Combining the drainage analysis result with other information derived from the MMS data, such as lane marking and debris/pavement distress locations, leads to a thorough examination of highway conditions, which are critical for prioritizing and planning maintenance. This study proposes a framework for mapping roadside ditches for slope and drainage analysis. The existing ground filtering approach – cloth simulation – is modified to handle the variations in point density of mobile LiDAR data. Hydrological analyses, including flow direction and flow accumulation, are applied to extract the drainage network from the digital terrain model (DTM). The cross-sectional/longitudinal profiles of the ditch are automatically extracted from LiDAR data, and visualized in 3D point clouds and 2D images. The slope derived from the LiDAR data compared very close with highway cross slope design standards of 2% on driving lanes, 4% on shoulder as well as 6-by-1 slope for ditch lines. Error propagation models and previous field test suggest this technology can map the vertical profile of a ditch with an accuracy of 2-3 centimeters at distances up to 30 meters from the mobile mapping vehicle.
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