Location
New York, New York
Date
15 Apr 2004, 7:00pm - 8:30pm
Abstract
A soil-bentonite slurry trench cutoff wall was installed as part of landfill improvements at the Macon County Landfill located in Decatur, Illinois. In order for a soil-bentonite barrier to be continuous and defect-free, a homogeneous, well-graded backfill needs to displace the slurry used to maintain trench stability. Historically, specifications required that the backfill have a unit weight of 15 pounds per cubic foot (pcf) higher than the unit weight of the in-trench slurry and the slurry have a maximum density of 85 pcf. More recently, specifications have also required that the sand content of the slurry, not exceed 10 to 15%. During the course of construction, difficulties arose which gave rise to post-construction investigations of the integrity of the completed cutoff wall. A program of field sampling and testing, which included Osterberg sampling, modified Osterberg sampling, and sonic-core borings, was developed to investigate the integrity of the wall. Since state-of-the-practice quality assurance and quality control measures are based upon field measurements and sampling during construction coupled with laboratory measurements of field-prepared backfill samples, detailed investigations of the in-situ, as-constructed wall are relatively uncommon and even more uncommonly documented in the literature. This paper presents these investigations, findings, conclusions derived from the investigations and provides recommendations for slurry wall design and construction derived from these studies.
Department(s)
Civil, Architectural and Environmental Engineering
Meeting Name
5th Conference of the International Conference on Case Histories in Geotechnical Engineering
Publisher
University of Missouri--Rolla
Document Version
Final Version
Rights
© 2004 University of Missouri--Rolla, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Evans, Jeffrey C.; Trast, John M.; and Frank, Randy L., "Lessons Learned from the Macon County Slurry Wall" (2004). International Conference on Case Histories in Geotechnical Engineering. 11.
https://scholarsmine.mst.edu/icchge/5icchge/session08/11
Lessons Learned from the Macon County Slurry Wall
New York, New York
A soil-bentonite slurry trench cutoff wall was installed as part of landfill improvements at the Macon County Landfill located in Decatur, Illinois. In order for a soil-bentonite barrier to be continuous and defect-free, a homogeneous, well-graded backfill needs to displace the slurry used to maintain trench stability. Historically, specifications required that the backfill have a unit weight of 15 pounds per cubic foot (pcf) higher than the unit weight of the in-trench slurry and the slurry have a maximum density of 85 pcf. More recently, specifications have also required that the sand content of the slurry, not exceed 10 to 15%. During the course of construction, difficulties arose which gave rise to post-construction investigations of the integrity of the completed cutoff wall. A program of field sampling and testing, which included Osterberg sampling, modified Osterberg sampling, and sonic-core borings, was developed to investigate the integrity of the wall. Since state-of-the-practice quality assurance and quality control measures are based upon field measurements and sampling during construction coupled with laboratory measurements of field-prepared backfill samples, detailed investigations of the in-situ, as-constructed wall are relatively uncommon and even more uncommonly documented in the literature. This paper presents these investigations, findings, conclusions derived from the investigations and provides recommendations for slurry wall design and construction derived from these studies.
