SgL Logo 03.gif
Laboratory Test Sheet
Triaxial Saturation - BS 1377 : Part 5 : 1990
Triaxial Saturation
Location Job ref.
Borehole/Pit no.
Soil description Sample No.
Group/Type Date Form
Test method                 BS1377: Part 8:  1990 Clauses 5.3/5.4*
Consolidated-undrained/consolidated-drained*triaxial compression test
With/without*side drains Date started Completed
Pressure system no. Cell no.
Required effective pressure s3 kPa Initial diameter Do mm
Cell pressure s3 kPa Initial length Lo mm
Back pressure ub kPa Initial area Ao mm2
Pore pressure after build-up ui kPa Initial volume Vo cm3
Excess pore pressure (ui - ub) kPa
Consolidation data
Date Time Elapsed time /t Volume change Pore pressure
t(min) indicator
  Reading Difference Reading Difference Dissipation
    u (ui - u) U
mL mL   kPa %
Final difference =
total consolidation volume change DVc
After consolidated
Consolidated volume Vc = Vo - DVc cm3 Coeffiecient of volume    
Volumetric strain ev =  DVc   Compressibility      
        Vo     mvi = 1000ev      
Consolidated length Lc = Lo(1 - 1/3 ev) mm   (ui - uc)      
Consolidated area Ac = Ao(1 - 2/3 ev) mm2 mvi = m2/MN  
Value of l   Value of F   Coeffiecient of      
From graph / t100 t 100 =  min Consolidation      
              cvi = 2.1 Ac      
Significant testing time   tf = Ft100 min   lt100      
Significant strain : assumed failure/reading intervals* ef =  
Calculated rate of axial displacement   dr = efLc   mm/min
Selected machine speed mm/min
Operator Checked Approved
*Delete as appropriate
Form 8C