Rapid Rehabilitation of Highway Slopes using Seeded Microbial Bio-Cement

This project will develop and field test a method using native grass and weed seeded microbial induced calcite precipitation (MICP) to mitigate wind and water erosion of highway slopes. In Stage 1, soil samples from new construction as well as intense forest fire burns will be collected from areas along roads, creeks, and dozer lines in several western states. Small portions of these samples will be subjected to index testing for geotechnical properties, examination under scanning and transmission electron microscopes (SEM and TEM), and chemical testing such as pH and calcium content. Also, biological microbial colony biome analysis will be performed for select samples. A large portion of each soil sample will be prepared into small molds for MICP treatment. Each specimen will undergo 0 to 6 incrementally increasing levels of MICP treatment with varying transient water inundation cycles after treatment. After treatment, one specimen from each set of treatment/inundation will be examined with TEM/SEM and tested for mechanical and drainage properties followed by testing for pH and other chemical indices. The remaining samples, not tested for mechanical and drainage properties, will be tested for wind and water erosion. The results are expected to provide unseeded soil erosion rates with and without MICP treatments at various levels. In parallel, native weed and grass seed mixes will be evaluated for use with MICP. Seed mixes for western states such as South Dakota, Wyoming, Montana, Colorado, and Nebraska will be evaluated. Weed and grass mixes that are heavily weighted towards rapid germination will be used. Sets of specimens with different seed mixes and MICP treatment levels will be prepared. Seed germination and growth will be measured and tracked for 90 days. Specimens for which seeds have germinated will be tested for erosion resistance. In Stage 2, a small-scale field study will be performed on new construction soils and forest fire burn areas local to Rapid City, South Dakota. Optimal seed and MICP treatments from Stage 1 will be applied to test areas of 20 square meters or less to confirm outdoor growth and erosion resistance under field conditions. Seed germination rates (# per square inch) at several discrete locations will be measured along with growth rates. Other observations on surface erosion or other conditions will also be made. Next, scaling-up of the MICP process for large scale field applications will be considered. Associated with the scaling-up will be life cycle cost analysis based on the most efficient treatment levels and a cost-benefits study of permitting and the environmental and water quality results to determine whether or not the potential environmental and permitting costs justify large-scale use of MICP. A preliminary investigation into the environmental impacts of seeded MICP treatment will be performed for water quality toxicity, eutrophication potential, and any changes in microbial colony. The final report will provide all data and test results along with guidelines for using native grass and weed seeded MICP to mitigate wind and water erosion of highway slopes as well as plans for implementation by state DOTs.

Language

  • English

Project

  • Status: Active
  • Funding: $135000
  • Contract Numbers:

    Project 20-30, IDEA 200

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Jawed, Inam

  • Performing Organizations:

    South Dakota School of Mines and Technology

    ,    
  • Principal Investigators:

    Lingwall, Bret

  • Start Date: 20180814
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01677699
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-30, IDEA 200
  • Files: TRB, RiP
  • Created Date: Aug 13 2018 3:03PM