Computational Technology Resources - CCP

Keywords: cutoff wall, impervious, landfill cap, permeability, porewater pressure, seepage, SEEP/W, soil-bentonite, uplift.

Summary

Cutoff walls have been used as vertical barriers to mitigate seepage of subsurface contaminants and to isolate contaminated materials, thereby permitting the safe reuse of sites without the need for complete removal of contamination. As part of the design of the Dallas Floodway Extension project, two soil-bentonite cutoff walls were incorporated into the design of a flood control project for the City of Dallas, Texas. These cutoff walls were located within two municipal waste landfills that were partially excavated to form a wetland cell, Cell F. Cell F was one of seven wetland cells that were incorporated into the design of the project to provide both flood damage reduction and environmental restoration benefits.

Construction of the wetland cell required the removal of nearly one million cubic yards (756,555m³) of waste from the landfills. However, since the bulk of the landfill was left in place, soil-bentonite cutoff walls were installed adjacent the excavation to prevent migration of leachate from the remaining materials into the wetland cell. Due to improper construction, one of the cutoff walls had the potential to allow seepage under the wall. This paper presents the numerical modeling of the East Cutoff Wall in the area of the defect. Numerical modeling was used to evaluate the performance of the as-built wall with respect to the performance required by the regulatory agency. The finite element program SEEP/W was utilized for the analysis, with data collected from instrumentation installed adjacent to the wall used to validate the results. After completion of the performance modeling for the defective as-built wall, SEEP/W was used to aid the design of repair alternatives. When implemented, the selected repair alternative will allow the project to meet the required regulatory standards and facilitate the efficient performance of the wetland over the long-term.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £95 +P&P)

	Computational & Technology Resources an online resource for computational, engineering & technology publications
	not logged in - login
Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 89 PROCEEDINGS OF THE SIXTH INTERNATIONAL CONFERENCE ON ENGINEERING COMPUTATIONAL TECHNOLOGY Edited by: M. Papadrakakis and B.H.V. Topping Paper 184 Seepage Analysis of Soil-Bentonite Cutoff Wall through Landfill A.F. Branch US Army Corps of Engineers, Fort Worth, Texas, United States of America doi:10.4203/ccp.89.184 purchase the full-text of this paper Full Bibliographic Reference for this paper A.F. Branch, "Seepage Analysis of Soil-Bentonite Cutoff Wall through Landfill", in M. Papadrakakis, B.H.V. Topping, (Editors), "Proceedings of the Sixth International Conference on Engineering Computational Technology", Civil-Comp Press, Stirlingshire, UK, Paper 184, 2008. doi:10.4203/ccp.89.184 Keywords: cutoff wall, impervious, landfill cap, permeability, porewater pressure, seepage, SEEP/W, soil-bentonite, uplift. Summary Cutoff walls have been used as vertical barriers to mitigate seepage of subsurface contaminants and to isolate contaminated materials, thereby permitting the safe reuse of sites without the need for complete removal of contamination. As part of the design of the Dallas Floodway Extension project, two soil-bentonite cutoff walls were incorporated into the design of a flood control project for the City of Dallas, Texas. These cutoff walls were located within two municipal waste landfills that were partially excavated to form a wetland cell, Cell F. Cell F was one of seven wetland cells that were incorporated into the design of the project to provide both flood damage reduction and environmental restoration benefits. Construction of the wetland cell required the removal of nearly one million cubic yards (756,555m³) of waste from the landfills. However, since the bulk of the landfill was left in place, soil-bentonite cutoff walls were installed adjacent the excavation to prevent migration of leachate from the remaining materials into the wetland cell. Due to improper construction, one of the cutoff walls had the potential to allow seepage under the wall. This paper presents the numerical modeling of the East Cutoff Wall in the area of the defect. Numerical modeling was used to evaluate the performance of the as-built wall with respect to the performance required by the regulatory agency. The finite element program SEEP/W was utilized for the analysis, with data collected from instrumentation installed adjacent to the wall used to validate the results. After completion of the performance modeling for the defective as-built wall, SEEP/W was used to aid the design of repair alternatives. When implemented, the selected repair alternative will allow the project to meet the required regulatory standards and facilitate the efficient performance of the wetland over the long-term. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £95 +P&P)
Back to top	©Civil-Comp Limited 2023 - terms & conditions