Use of Biocementation for Slope Stabilization of Levees

While levee embankments are the first line of defense for urban flooding, recent flooding events have revealed widespread slope instability of embankments around the country that can lead to levee failures. This work aimed to improve the slope stability of earthen levees by strengthening the soil through the use of a biologically-inspired technique called biocementation. The major objective of this study was to determine the optimal and most practical biocementation method that results in the best performance of levee slopes under various flooding conditions. A novel biocementation method called bacterial enzyme-induced calcite precipitation (BEICP) was tested. This method differs from the well-studied microbial-induced calcite precipitation (MICP) method mainly in the size of the biological agent (whole bacterial cell vs. enzyme), which influences the agent’s mobility in soils of different grain sizes. The BEICP methods for soil strengthening were optimized in laboratory-scale column experiments. The optimized methods were then used to construct levees in an experimental flume system. The results indicated that the BEICP treatment resulted in significant strengthening of the surface of the soil specimens, which were measured as increases in unconfined compressive strength. The strengthened samples were able to resist erosion for a longer time period under overtopping scenarios of water challenges with high water velocity in a flume. Therefore, BEICP offers a sustainable and economical method for treatment of soil surfaces to improve erosion resistance. The results of this study will help mitigate flooding events that could cause major issues in transportation infrastructure and traffic safety.

Language

  • English

Project

  • Status: Completed
  • Funding: $162233
  • Contract Numbers:

    DTRT13-G-UTC37

  • Sponsor Organizations:

    Midwest Transportation Center

    Iowa State University
    2711 S Loop Drive, Suite 4700
    Ames, IA  United States  50010-8664

    Office of the Assistant Secretary for Research and Technology

    University Transportation Centers Program
    Department of Transportation
    Washington, DC  United States  20590

    Iowa State Universtiy

    Civil, Construction, and Environmental Engineering
    394 Town Engineering
    Ames, Iowa  United States  50011
  • Managing Organizations:

    Iowa State University, Ames

    Institute for Transportation
    2711 South Loop Drive, Suite 4700
    Ames, Iowa  United States  50010-8664
  • Performing Organizations:

    Iowa State University, Ames

    Institute for Transportation
    2711 South Loop Drive, Suite 4700
    Ames, Iowa  United States  50010-8664
  • Principal Investigators:

    Ikuma, Kaoru

    Cetin, Bora

    Rehmann, Chris

    Ong, Say Kee

  • Start Date: 20160901
  • Expected Completion Date: 20181130
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01618658
  • Record Type: Research project
  • Source Agency: Midwest Transportation Center
  • Contract Numbers: DTRT13-G-UTC37
  • Files: UTC, RiP
  • Created Date: Dec 2 2016 12:23PM