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The following calculations are used in this test:

 

Deformation

 

The axial deformations can be specified directly or using deformation dial readings. When using dial readings they are converted to actual deformations using a dial constant.

 

Da = (Ra - Rai) * ADC                        

 

where,

Da        = Axial deformation

Ra        = Axial dial reading

Rai        = Initial axial dial reading

ADC        = Axial dial constant

 

 

Axial Load

 

The Axial loads can be specified directly or using readings from a load ring. When using readings from a load ring the readings are converted to loads either using load ring constants or a linear equation.

 

Load Ring Constant

 

If R < Crossover        Pa = R * LRC1                

 

If R > Crossover                Pa = Crossover * LRC1 + (R - Crossover) * LRC2

 

Linear

 

Pa = M * R + C

 

where,

Pa        = Axial load

R        = Load dial reading

LRC1        = Load ring constant 1

LRC2        = Load ring constant 2

M        = Linear multiplier

C        = Linear constant

 

 

Axial Strain

 

εa = Da / h        

 

where,

εa        = Axial strain

Da        = Axial deformation

h        = Initial height of specimen

 

Axial Stress

 

σ = Pa / A

 

where,

σ        = Axial stress

Pa        = Axial load

A        = Cross-sectional area = A0 / (1 - εa)

A0        = Initial cross-sectional area = π * d2 / 4

d        = Initial diameter

 

 

Water Content

 

wi (%) = 100 * (Mbwt - Mbdt) / (Mbdt - Mbt)                

 

where,

wi        = Initial percentage water content

Mwt        = Mass of tare and wet specimen

Mdt        = Mass of tare and dry specimen

Mt        = Mass of tare

 

 

Dry Density

 

ρi = Mw / V / (1+ wi/100)                        

 

where,

ρi        = Initial dry density

Mw        = Wet sample mass

V        = Sample volume

wi        = Initial water content (%)

 

 

Dry Unit Weight

 

γi = ρi * γw                                        

 

where,

γi        = Initial dry unit weight

γw        = Unit weight of water (9.807 kN/m3)

 

 

Saturation

 

Si (%) = 100 * Vwi / Vvi                                

 

where,

Si        = Initial saturation

Vwi        = Initial volume of water in sample = (Mw - Ms) / ρw

Vvi        = Initial volume of voids = Vi - Vs

Vs        = Volume of solids = Ms / (SG * ρw)

Ms        = Mass of solids = Mw / (1 + wi / 100)

ρw        = Density of water (1.0 g/cm3)

SG        = Specific gravity

 

 

Void Ratio

 

ei = Vvi / Vs                                        

 

where,

ei        = Initial void ratio