Identification and behavior of collapsible soils.

Details

• Alternative Title:
  Joint Transportation Research Program : Civil Engineering
• Creators:
  El Howayek, Alain ; Huang, Pao-Tsung ; Bisnett, Rachael ; Santagata, Maria Caterina
• Corporate Creators:
  Purdue University. Joint Transportation Research Program
• Corporate Contributors:
  Indiana Department of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Collapsible soils
  • Soils by strength
  • Oedometers
  • Instruments for measuring loads or pressure
  • Collapse strength
  • Collapse properties
  • Wetting
  • Loess
  • Collapsibility
  • Double oedometer
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• Publication/ Report Number:
  FHWA/IN/JTRP-2011/12
• Resource Type:
  Tech Report
• Geographical Coverage:
  Indiana
• Corporate Publisher:
  Purdue University. Joint Transportation Research Program
• Abstract:
  Loess is a soil that can exhibit large deformations upon wetting. Cases of wetting induced collapse in loess have ; been documented for natural deposits and man-made fills. These issues are of concern to the Indiana DOT due to the growth ; of the state’s infrastructure in regions with significant loess deposits. ; The research reviewed the existing literature on loess, focusing on index properties, structure, mineralogy, criteria ; used for quantifying collapsibility, methods for measuring collapse potential, and, in particular, the collapsibility of ; compacted loess. Additionally, available documentation on loess deposits in Indiana was reviewed and summarized. ; This research also included experimental work conducted on two loess samples, obtained in one in Daviess (Soil A) ; and in Tippecanoe (Soil B) county. The soils have similar characteristics, with close to 70% silt content and plasticity ; characteristics that classify both of them as CL (USCS) and A-6 (AASHTO). ; Experiments performed on the two soils included index tests, standard Proctor compaction tests, and an extensive ; program of double odeometer tests to measure the wetting induced strains as a function of stress level. Specimens of soils A ; and B were compacted over a wide range of values of relative compaction (from 75% to close to optimum) and of water ; contents (from 5-6% points dry of optimum to optimum). The collapse potential of each specimen was quantified using the ; ASTM D5333 criterion. All specimens but one (compacted at close to optimum conditions) showed some wetting induced ; collapse. The collapse strains increased with decreasing relative compaction and decreasing compaction water content, in ; some cases exceeding 10%. In some tests significant wetting induced strains were measured under relatively small stresses ; (50-100 kPa), indicating that this problem may require consideration even for small fill heights. ; The results of the experiments were compared to literature data for other soils, and overall found to be consistent ; with previously reported behavioral trends. Based on the results of the testing, recommendations are made for field ; compaction specifications.
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• Format:
  PDF
• Funding:
  SPR-3109
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/23601/dot_23601_DS1.pdf
• File Type:
  [PDF - 22.09 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:4f5fc30767f5206cff94b9631efe977164650230b773a563ee65f5053c20d56b80db7c69c5a0bbdc0318afa067ddfacf2d5423ede1b10546be737cfe470a1543