Description
The SWCC machine is used for determining the influence of the stress states on the Soil Water Characteristic Curve (SWCC) of a soil sample. This system is developed to perform SWCC test, conforming to ASTM D6836-16. This system allows determination of both wetting and drying SWCC. The suction is generated using a pro pneumatic APC at the top of the sample and a pro hydraulic APC at the base, applying the axis translation technique. Some of the equipment features are as follows
- Air-tight cell fitted with High Air Entry Disc ( 5 bar) for 70 mm diameter and 20 mm height sample.
- Internal submersible load cell.
- On-board data logging with large data storage (up to 14 million records) using SD card (8GB standard).
- High speed sensor conversion (24 bit, up to 4000 samples/sec).
- Frame can also be used with the same cell for constant rate-of-strain (CRS) and Consolidation tests.
Testing Ranges
Purpose:
- Develop wetting and drying soil water characteristic curves for soils.
- Obtain the unsaturated shear strength parameters.
- Develop stress paths for field applications.
- Establish the relationship between stress state variables and deformation strain state variables for unsaturated soil.
- Determine the fluid flow conditions in unsaturated soils and obtain unsaturated coefficient of permeability.
- Determine the relationship between matric suction pressure and the moisture holding capacity of soils for various confinements.
Ranges:
- Maximum Frame Capacity: 15kN
- Load cell: 25 kN
- Automatic Pressure controller
- Hydraulic: 1000kPa
- Pneumatic: 1000kPa
- LSCT Displacement Transducer: 25 mm X 0.001 mm
- Pressure Transducer: 10 Bar
- Maximum Cell Capacity: 2000 kPa
Material Properties
- Characterize matric potential of unsaturated soils with varying moisture contents.
- Unsaturated Hydraulic Conductivity.
Field Applications
- Design parameters for earthen dams, levees, retaining wall
- Modeling water distribution and flow in unsaturated soil.
- Designing foundation on unsaturated soils.
Publications
- Puppala, Anand J., Koonnamas Punthutaecha, and Sai K. Vanapalli. “Soil-water characteristic curves of stabilized expansive soils.” Journal of Geotechnical and Geoenvironmental Engineering 132, no. 6 (2006): 736-751.
- Hoyos, L. R., H. R. Thudi, and A. J. Puppala. “Soil-water retention properties of cement treated clay.” In Problematic Soils and Rocks and In Situ Characterization, pp. 1-8. 2007.
- Punthutaecha, K., and A. J. Puppala. “SOIL-WATER CHARACTERISTICS OF FLY ASH STABILIZED SOIL.