Design Criteria for Highway Embankments Reinforced with Geosynthetic Material Exposed to Localized Wave Forces

Unlike the designs of regular highway embankments or levees, the crest level of a coastal highway embankment must be determined by seriously considering the sea level rising. In the design of a coastal highway embankment, soil fills at different elevations are reinforced with geosynthetic reinforcement. To design effective and reliable geosynthetic reinforcement (tensile force calculation, determination of the reinforcement lengths and vertical spacings, etc.), it is imperative to modify the existing design methods. A coastal highway embankment is typically subjected to strong hydro-dynamic wave pressures. Therefore, during the design process, maximum hydro-dynamic wave pressures consistent with a storm/hurricane with a design return period must be applied to the embankment. This research aims to develop geometrical and structural design criteria of highway embankment in coastal areas. The design should consider the varying hydrodynamics of the coastal area, including wave height, wave period, and tidal fluctuations. The research will be focused on: (1) Determinations of wave height, embankment crest elevation and freeboard; (2) Reinforcement design of the geosynthetic materials at the bottom of embankment and in the embankment fills of different layers. The proposed research will consist of the following tasks. Task 1 involves conducting a review of pertinent literature. Task 2 is the determination of the Design Water Level (DWL). Determination of DWL was an integral part of the Louisiana marsh creation project, which necessitated an extensive analysis of Water Surface Elevation (WSE) data. So far, the analytical procedure has selectively incorporated historical WSE readings from three strategic locations. In this current research, more station data will be investigated to cover more coastal areas in Louisiana. Determination of the embankment crest level is Task 3 of this project. Determination of an embankment crest level is important for ensuring that the embankment can withstand future conditions when sea level is heightened. To calculate the embankment crest level, the design water level (the highest expected water level) and the safety margin called freeboard will be used. Unlike taking a one-foot high tradition for the freeboard, the team will be following recommended formulations to complete the calculations. Task 4 is related to the development of an effective method for the designs of the geosynthetic fabric as reinforcement in highway embankment fills. The traditional 'breaking' and 'pullout' failure mechanisms for the reinforcing geosynthetic materials in embankment fills will be followed for this purpose. Large-scale direct shear tests will be conducted to understand the frictional interaction mechanisms between the geosynthetics and embankment fills.

• Record URL:
  • https://www.sptc.org/cy2-ltu-03

Language

• English

Project

• Status: Active
• Funding: $76,000
• Contract Numbers:

  69A3552348306

  CY2-LTU-03

• Sponsor Organizations:

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Managing Organizations:

  Southern Plains Transportation Center

  University of Oklahoma
  202 W Boyd St, Room 213A
  Norman, OK  United States  73019
• Project Managers:

  Dunn, Denise

• Performing Organizations:

  Louisiana Tech University, Ruston

  Ruston, LA  United States  71272
• Principal Investigators:

  Wang, Jay

• Start Date: 20241001
• Expected Completion Date: 20250930
• Actual Completion Date: 0
• USDOT Program: University Transportation Centers

Subject/Index Terms

• TRT Terms: Coastal engineering; Embankments; Failure analysis; Geosynthetics; Highway design; Hurricanes; Hydrodynamics; Sea level
• Geographic Terms: Louisiana
• Subject Areas: Design; Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 01939092
• Record Type: Research project
• Source Agency: Southern Plains Transportation Center
• Contract Numbers: 69A3552348306, CY2-LTU-03
• Files: UTC, RIP
• Created Date: Dec 10 2024 1:50PM