THE STRENGTH OF COMPACTED COHESIVE SOILS

PHYSICO-CHEMICAL CONCEPTS AND ENVIRONMENTAL FACTORS ARE INTRODUCED TO EXPLAIN THE IMPORTANCE OF THE NET INTERPARTICLE FORCES IN FINE GRAINED COHESIVE MATERIALS. IT IS POINTED OUT THAT THE SOIL COMPOSITION HAS A PRIMARY INFLUENCE UPON THE STRENGTH OF COMPACTED CLAYS. THE SOIL COMPOSITION INCLUDES NOT ONLY THE MOLDING WATER CONTENT AND DRY DENSITY, BUT ALSO THE SOIL STRUCTURE. IT IS SHOWN FROM THE TEST RESULTS UNDER CAREFULLY-CONTROLLED TEST CONDITIONS THAT THE CHANGES IN THE PORE WATER PRESSURES AND THE SHEARING RESISTANCE IN RESPONSE TO INCREASING AXIAL STRAINS IN THE TRIAXIAL COMPRESSION TESTS ARE SIGNIFICANTLY DIFFERENT ON THE DRY AND WET SIDE OF OPTIMUM FOR ANY GIVEN METHOD OF COMPACTION. THE MAGNITUDE OF DIFFERENCES IS SHOWN TO DEPEND UPON THE DIFFERENT SOIL STRUCTURES CAUSED BY THE DIFFERENT COMPACTION METHODS. THE DIFFERENCES IN THESE BEHAVIOR CHARACTERISTICS ARE EXPLAINED IN TERMS OF THE DIFFERENCES IN SOIL STRUCTURE. BASED ON THE TRENDS OF CHANGES IN SECANT MODULI OF DIFFERENT STRAIN LEVELS, WITH INCREASING MOLDING WATER CONTENTS, ALONG THE SAME COMPACTION CURVE OBTAINED FROM DIFFERENT COMPACTION METHODS, THE SIGNIFICANCE OF THE FAILURE CRITERION IN PREDICTING THE MOLDING WATER CONTENT-DRY DENSITY-STRENGTH RELATIONSHIPS IS EMPHASIZED. ALSO, DATA IS COVERED ON THE EFFECTS OF THIXOTROPY, DURATION AND RATE OF LOADING, THE MAGNITUDE, FREQUENCY AND DURATION OF THE REPETITIVE LOADING ON THE STRENGTH CHARACTERISTICS. THE INFLUENCE OF DIFFERENT METHODS OF COMPACTION ON THE SWELLING AND SWELL PRESSURES ARE PRESENTED. THE APPENDIX INCLUDES INFORMATION ON THE TECHNIQUES OF PREPARATION OF SAMPLES FOR CONTROLLED TESTS, TRIAXIAL TEST PROCEDURES, DISCUSSION OF TEST ERRORS, AND THE EFFECT OF TEMPERATURE VARIATION ON PORE PRESSURES.

• Corporate Authors:

  American Society of Civil Engineers

  Res Conf On Shear Strength of Cohesive
  ,   United States 
• Authors:
  • Seed, H B
  • Mitchell, J K
  • CHAN, C K
• Publication Date: 0

Language

• English

Subject/Index Terms

• TRT Terms: Clay; Cohesive soils; Compression; Dry density; Forming; Loads; Modulus; Moisture content; Pore pressure; Pore water pressures; Properties of materials; Secant; Shear strength; Soil compaction; Soil structure; Soils; Strain (Mechanics); Strength of materials; Swelling; Temperature; Test procedures; Thixotropy; Triaxial shear tests
• Uncontrolled Terms: Axial strain; Loading rate; Triaxial compression
• Old TRIS Terms: Dry density (Soils); Secant modulus; Soil composition; Test results
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00231422
• Record Type: Publication
• Source Agency: Highway Research Board Bibliography
• Report/Paper Numbers: pp 877-964
• Files: TRIS
• Created Date: Aug 15 2004 2:24AM