Data on Compression Curves

  

The provided CSVs contain the raw data used to plot the compression curves in Figs. 2, 4 and 5, respectively. These data were extracted from Yang et al (2006a) (https://doi.org/10.1520/GTJ14010).

· Maximum and Minimum Void Ratios Determination:

1. ASTM Procedures (D 4253-00, D 4254-00): Used for soils with up to 15% soil particles passing sieve No. 200 (0.075 mm) without cohesion.

2. Maximum Void Ratio: Determined by pouring dry material into a mold using a funnel three times and averaging the void ratios.

3. Minimum Void Ratio: Determined using both the Standard Proctor test method and vibration method.

· Back Pressure for Saturation:

1. 800 kPa: To ensure full saturation, achieving B-values exceeding 0.96, often above 0.98 for samples with over 10% fines content.

Experimental Condition

· Sample Preparation:

1. Moist Tamping Under-Compaction Method by Ladd (1978): Used to prepare samples to avoid segregation of fines and improve uniformity.

· Triaxial Testing:

1. Free Ends and Lubricated End Platens: Used to overcome the barreling effect and concentration of dilation in local zones.

2. Sample Dimensions: Diameter to height ratio of 1.

3. Types of Tests:

· Static Drained and Undrained Compression Tests: Conducted using closed-loop automatic triaxial test equipment.

· B-values: Discussed in detail, with accurate measurements ensured.

· Cyclic Tests: 

1. 56 Tests: Conducted using servo pneumatic and mechanical controlled systems.

Nomenclature

• SSL (Steady State Line): Line representing steady state points at 30% axial strain in drained tests.
• TFC (Total Fines Content): Calculated based on index data, should be between 19% and 36%.
• IL (Instability Line): The line connecting peaks of deviatoric  stresses in undrained compression tests indicates potentially unstable stress states.
• Peak Stress Ratio: Ratio between peak deviatoric stress and peak mean effective stress, with or without cohesion.
• c: Cohesion.
• φ: Effective friction angle.
• a: Attraction (a = c / tan φ).
• Slope of Instability Line (λ): Determined from triaxial tests with different stress ranges.
• Instability Curve: Relationship between peak stress and void ratios after consolidation.