SWCC Test

This device is a simple unsaturated soil testing apparatus with the capability of applying wide range of matric suction values (0 to 500 kPa) while following various stress paths. One of the major outcomes for this device is to develop the soil water characteristic curve (SWCC) for a soil. The device can be used to obtain the complete SWCC for a soil. It is capable of applying one-dimensional loading, K_o, to a specimen with a diameter up to 71 mm. SWCCs can be performed on ‘as-compacted’, ‘initially slurried’, or ‘undisturbed’ specimens, starting with either dry or wet conditions. The pore-air pressure at the top of the specimen can be controlled through the use of dual pressure regulators and precise gauges. Some of the special features of this equipment are listed below.

• In situ overburden pressure can be applied during the test
• Compression (volume change) & water content measurements
• Applied suctions up to 500 kPa
• Both drying (desorption) and wetting (adsorption) pressures can be measured
• Dual pressure gauges and regulators for precise pressure control
• Null-type initial suction measurements using axis-translation technique
• Flushing ability and measurement of diffused air
• Pressure compensator on the loading ram

• Development of soil retention curve which can establish the link between field and laboratory conditions
• Establishment of the relation between stress state variables and deformation strain state variables for unsaturated soil
• Determine the unsaturated shear strength parameter
• Determination of the air-entry value of the soil
• Determine the water flow capabilities/unsaturated coefficients of permeability 
• Determine the amount of water and the energy state in water phase
• Development of stress paths at various field conditions

Air-entry value, unsaturated strength parameters, unsaturated hydraulic conductivity.

Design of geotechnical structures such as earth dams, slopes, earth-retaining structures.

• Patil, Ujwalkumar D., Laureano R. Hoyos, Anand J. Puppala, and Surya Sarat Chandra Congress. “Suction Stress Characteristic Curves of Cohesive-Frictional Soils from Multiple Suction-Controlled Testing Methods.” International Journal of Geomechanics 20, no. 7 (2020): 04020077.
• Banerjee, Aritra, Anand J. Puppala, Prince Kumar, and Laureano R. Hoyos. “Stress-Dilatancy of Unsaturated Soil.” In Geo-Congress 2020: Geo-Systems, Sustainability, Geoenvironmental Engineering, and Unsaturated Soil Mechanics, pp. 420-429. Reston, VA: American Society of Civil Engineers, 2020.
• Banerjee, Aritra, Anand J. Puppala, and Laureano R. Hoyos. “Suction-controlled multistage triaxial testing on clayey silty soil.” Engineering Geology 265 (2020): 105409.
• Banerjee, Aritra, Anand J. Puppala, Laureano R. Hoyos, William J. Likos, and Ujwalkumar D. Patil. “Resilient modulus of expansive soils at high suction using vapor pressure control.” Geotechnical Testing Journal 43, no. 3 (2020).
• Banerjee, Aritra, Ujwalkumar D. Patil, Anand J. Puppala, and Laureano R. Hoyos. “Suction-controlled repeated load triaxial test of subgrade soil at high suction states.” In Unsaturated Soils, Proceeding of Seventh International Conference on Unsaturated Soils. Hong Kong, China: HKUST, pp. 667-672. 2018.
• Banerjee, Aritra, Ujwalkumar D. Patil, Anand J. Puppala, and Laureano R. Hoyos. “Evaluation of Liquefaction Resistance in Silty Sand via Suction Controlled Cyclic Triaxial Tests.” In PanAm Unsaturated Soils 2017, pp. 543-552. 2018.