GEOTECHNICAL ENGINEERING LABORATORY
The Geotechnical Engineering laboratory is equipped with high-end research equipment along with basic soil testing. The soil dynamics laboratory is equipped with large (earthquake) and small strain (vibratory) testing. Large strain dynamic loading: cyclic triaxial test setup (0.01Hz-2Hz, stress and strain controlled); cyclic simple shear setup (0.001Hz-5Hz, stress and strain controlled) to evaluate liquefaction, shear modulus & damping ratio of soils up to 10,000 loading cycles. Small strain dynamic loading: bender element system to determine shear modulus under K0, stress path, isotropic, UU, CU, CD compression and extension loading conditions. Shear strength facility consists of direct shear setup for cohesionless soils, unconfined compression (UC) test for cohesive soils, vane shear test for soft soils, and triaxial setup with DAQ and analysis software for all soil types. Pore pressure and volume change measurement facility are available for compression/extension loading (UU, CU, CD tests), K0 consolidation and stress path testing. Large direct shear setup is also available to study the interface behavior of various types of geosynthetics-soil system. Dew point potentiometer is available to determine total suction (0-300 MPa) of fine-grained soils, conventional tensiometer for coarse-grained soils, and filter paper setup for matric suction of all soil types. The facility includes falling and constant head devices for the permeability of fine and coarse-grained soils, four 3-gang oedometer (1D consolidation) setup, proctor setup, CBR for the strength of subgrade soil, sieve shaker, hydrometer, Atterberg limit (LL,PL,SL), swell pressure, specific gravity, relative density, core cutter, sand replacement, muffled furnace (900oC) for organic matter evaluation, optical and digital LCD microscopes. The field testing laboratory has plate load test of 300 kN capacity with motorized anchoring system, standard penetration test (SPT), dynamic cone penetration test (DCPT) with automatic free-fall hammering system, vibratory plate compactor for field compaction, field permeability setup, ground penetration radar (GPR) with mono and bistatic operations facilitated with antennae of frequencies 100MHz, 400MHz with the bistatic operation and 200MHz and 900MHz with the monostatic operation including 20-80 multi frequency antennae, multichannel analysis of surface waves (MASW) setup with the provision of Seismic Refraction/Reflection Survey and Downhole/Crosshole tests. The following equipment were developed in the laboratory: multiaxial cubical device with flexible boundary system along with real-time feedback control system capable of conducting true-triaxial and plane strain testing of soils, constant rate of strain (CRS) consolidation setup, slurry consolidation setup for preparing the remolded specimens of fine-grained soils.
Dr. Ajanta Sachan
Indian Institute of Technology Gandhinagar
Palaj, Gandhinagar, Gujarat, India – 382355