Foundation Design

Quick Undrained Triaxial Compression
Liquid and Plastic Limits
Water Content
Particle Size Distribution
Effective Stress
Consolidation Testing
Back to Applicable Tests

Pocket penetrometer

Description:

  • Pocket penetrometer Shear Strength (up to 3 determinations)

Results given:

  • Shear Strength

You provide:

  • No information required

Typical use(s):

  • Quick, inexpensive indication of shear strength, but it should only be used when other, more preferable and accurate determinations of shear strength are not possible
  • Pile design
  • Immediate bearing capacity

Material required:

  • Intact lump at least 4cm cubed for single determination (larger sample will give more determinations)

(Atterberg Limits)

Description:

  • Liquid and plastic limits of soil – 4 point cone penetrometer method

(BS EN ISO 17892-12: Clauses 5:3 and 5:5 : 2018)

  • Liquid and plastic limits of soil – 1 point cone penetrometer method

(BS EN ISO 17892-12: Clauses 5:3 and 5:5: 2018)

Results given:

  • Liquid limit
  • Plastic limit
  • Plasticity index
  • % retained on 425μm sieve

You provide:

Specify which method is required –

  • 1 point
  • 4 point

Typical uses(s):

  • Basic classification of material according to its behaviour

Material required:

  • Enough sample to provide 300g of material passing a 425μm sieve

Description:

  • Water content of soil (BS EN ISO 17892-1: 2014)
  • Moisture content of soil (BS1377: Part 2: Clause 3:2 : 1990)

Results given:

  • Water or moisture content (as % of water to dry mass)

You provide:

  • No information required

Typical use(s):

  • Basic material property

Material required:

  • Fine grained – 50g
  • Medium grained – 300g
  • Coarse grained – 3kg

(sieve & mechanical analysis)

Description:

  • Particle Size Distribution by Wet sieve analysis (BS EN ISO 17892-4:2016, clause 5.2)
  • Particle Size Distribution by Dry sieve analysis (BS EN ISO 17892-4:2016, clause 5.2)
  • Mechanical analysis by Hydrometer method (BS EN ISO 17892-4:2016, clause 5.3)
  • Mechanical analysis by Pipette method (BS EN ISO 17892-4:2016, clause 5.4)

Results given:

  • Grading of material (% of each particle size)
  • Percentages of clay and silt fractions (if pipette or hydrometer analysis performed)

You provide:

  • Specify if pipette analysis is required to individually determine clay and silt content
  • If pipette or hydrometer analysis is specified, what quantities of fine material (passing 63μm sieve, clay and silt) needs to be present to require the pipette or hydrometer analysis to be performed (eg. Only if >10% fines present)

Typical use(s):

  • Basic classification of material according to its particle size

Material required:

Depends on particle size. For not more than 10% of the following sizes, uses the corresponding sample mass –

 

 

Size                                     Sample Mass

63mm                                40kg

50mm                                35kg

37.5mm                            14kg

28mm                                6kg

20mm                                2kg

14mm                                1kg

10mm                                500g

6.3mm                               300g

3.35mm                            200g

<2mm                                100g

Description:

  • Consolidated Undrained

Results given:

  • Cohesion (c’)*
  • Angle of friction (phi’)*
  • Density
  • Moisture Content
  • Deviator Stress and Strain at peak

*for multistage or sets of specimens

You provide:

  • Remoulding conditions (if applicable)
  • Effective pressure(s) (eg. 50, 100, 200 kPa)

Typical use(s):

  • Slope stability
  • Foundation design

Material required:

Undisturbed

  • Sample with a core length of about 2:1 length: dia ratio of full diameter, intact material (ideally at least 2.5:1 length: dia to allow for trimming)
  • Block sample twice the size of 2:1 length: dia sample required

Remoulded

  • 200g of <6mm material for 38mm diameter specimen
  • 4kg of <20mm material for 100mm specimen

Description:

  • Consolidation properties in oedometer – Incremental loading oedometer test on undisturbed soil specimens (includes mandatory reporting) (BS EN ISO 17892-5: 2017)
  • Consolidation properties in oedometer (includes mandatory and optional reporting requirements) (BS EN ISO 17892-5: 2017)
  • Addition of swelling pressure determination
  • Extra over 5 days in excess of initial 5 days
  • Remoulding specimen at as-received
  • Water content

Results given:

  • Swelling pressure (if performed)
  • Voids ratio v log of pressure plot
  • Coefficient of consolidation
  • Coefficient of volume compressibility

You provide:

  • Specify if swelling pressure is to be determined
  • Specify pressure sequence to be applied

Typical use(s):

  • Behaviour of ground to changes of loading

Material required:

  • Ideally, an undisturbed length of sample at least half as long as the diameter, and at least 10mm greater in diameter than the required specimen (typical specimen 76mm dia.)
  • If remoulded, 200g