Geomechanics/Geotechnical Research Group

You are here: Home / Research / Testing Facilities and Equipments / Consolidation and Swell Testing Systems / 1-D Consolidation Machine

1-D Consolidation Machine

 

The 1-D Consolidation setup can be used to perform 1D consolidation which is capable of applying step loading as well as displacement control using a stepped motor. The setup is capable of running BS EN ISO 17892-5 (2017), BS1377, ASTM D2435, AS1289.6.6.1, XP P94 test standards. The loading and unloading sequence/increment can be user defined and run automatically with live display of logged and calculated data (T50, T90).

This test help determine parameters that can be used to estimate both magnitude and time rate of the settlement using conventional consolidation theory by Terzaghi.

  • Max load = 3300 lbf (15kN)
  • Resolution: 0.1 N (0.0225 lbf)
  • Accuracy: 0.15% FRO
  • Sample size = 2” (50 mm) and 4” (100 mm)
  • Displacement range = 0.0001 – 0.3937 in/min (0.0001 – 10 mm/min)
  • Dimensions (W x D x H): 280 x 320 x 930 mm (11″ x 12.75″ x 36.6″)
  • Weight: 31 kg (68 lb)

Consolidation Properties

  • Preconsolidation pressure, σ’p
    • The overburden stress that marks the boundary between NC (loose) and OC (dense) deformation response of a soil to loading
    • Usually indicative of past pressure experienced by the soil from glaciers or eroded layers
  • Recompression Index, CR = Δe/Δlog(σ’v)
    • Indicates the behavior of soil volume change under loads less than the preconsolidation pressure.
    • It could also be used to approximate swelling due to unloading.
  • Compression Index, CC = Δe/Δlog(σ’v)
    • Indicates the change of soil volume under loads greater than the preconsolidation pressure
  • Duration of Primary Consolidation, tp
  • Secondary Compression Index, Cα = Δe/Δlog t
    • Indicates the soil volume change under a constant loading.

Sample output graph.

  • Estimation of foundation settlement.
  • Design and analysis of soft ground.
  • Analysis of settlement characteristics of landfill.
  • Design of road pavement for expansive soils.
  • Cai, Guojun, Songyu Liu, and Anand J. Puppala. “Consolidation parameters interpretation of CPTU dissipation data based on strain path theory for soft Jiangsu quaternary clays.” Marine Georesources & Geotechnology 33, no. 4 (2015): 310-319.
  • Sekhar Madhyannapu, Raja, Madhira R. Madhav, Anand J. Puppala, and A. Ghosh. “Compressibility and collapsibility characteristics of sedimented fly ash beds.” Journal of materials in civil engineering 20, no. 6 (2008): 401-409.