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    Vane Shear Testing Procedure

    For a PDF copy please download 09-09-03 Vane Shear Procedures.PDF

    CPT Test Categories

    For a PDF copy please download CPT Test Category Classification System.PDF

    EXPLANATION OF CPT TEST CATEGORIES TABULATED BELOW

    At IGS we define “quality service” as being satisfactory implementation of the class or type of test required by the client, to suit their particular needs.

    Note that:
    • It is certainly not high quality to fail to meet any particular client’s technical expectations.


    • Equally though, neither is it high quality to provide a class or type of test that a client neither needs nor wants for their particular application. Particularly, for instance, if that class or type of test takes longer and/or costs more than a less costly test that would otherwise have fully suited the client’s needs.
    As we offer a range of different CPT test Categories, all of “high quality” for their particular application, it is convenient to tabulate these and define a system of test designation (ie test-category-name) to assist in communicating with clients and helping them direct IGS as succinctly as possible in regard to their needs.

    There is no international or Australian standard that we can usefully follow in preparing this categorisation system so we have prepared our own hierarchy of test categories and self designated these as tabulated below.

    The classification system has evolved from our own experience with our own clients and is a reflection of our own current opinions.

    We would appreciate any feedback from any client and advise that the classification system might evolve with time and with hoped-for constructive client feedback.

    TEST CATEGORIES
    Name Brief Description (and client role) Typical Application Methods Typically
    Employed by IGS Operator
    IGS-1S or IGS-1C Standard Piezo Cone Testing

    Client must (pre-testing) brief IGS on their choice of category. Little or no client involvement is required during testing progress.

    Objective is good quality data, including good pore pressure response with IGS-1. However, if pore pressure response problems evolve in any “difficult” test zone, time is not squandered trying to solve them.

    Typically a client is hoping for reasonably high productivity using this method.



    For use when clients want a reliable soil profile and to establish design parameters to historically-normal levels of client expectation.

    May be the base test type chosen for a known soft clayey soil project for overall site profiling.

    With IGS-1, good quality pore pressure response is usually achieved and "normal" dissipation tests can be made.



    Usually 100MPa cone is used; either and S-Type cone or a C-Type Cone. These are discussed in an attached IGS Technical note. 1S denotes and S-Type cone, 1C denotes a C-Type cone.

    Cone is carefully prepped to ensure best reasonably achievable piezo saturation and absence of trapped or dissolved air.

    Pore pressure measurements are made as test progresses.

    If soil behaviour spoils piezo response in some zones, test penetration is paused (but only briefly) to promote “catch up”.

    Should difficult soil layers be encountered (eg gravely bands or hard fissured layers causing tilt), test type IGS-S1 can sometimes be carefully continued – at discretion of IGS operator.
    IGS-2S or IGS-2C Non-Piezo-Cone Testing

    Client must (pre-testing) brief IGS on their choice of category.

    As cone does not have a piezo-element, cone preparation is much simplier and quicker - leads to higher project productivity.



    For use when clients want a reliable soil profile and to establish design parameters at “site characterisation” level. But pore pressure response is not required.

    May be the base test type chosen for a variable or unknown soil type for overall site profiling. IGS recommends this if budget control is critical and site characterisation is the objective



    Usually 100MPa cone is used; either an S-Type cone or a C-Type cone. These are discussed in a following Technical Note. 2S denotes an S-Type cone, 2C denotes a C-Type cone.

    Should difficult soil layers be encountered (eg gravely bands or hard fissured layers causing tilt), test type IGS-2S can sometimes be carefully continued – at discretion of IGS operator.
    IGS-3S or IGS-3C Special-Class Testing.

    Client must (pre-testing) brief IGS on their choice of category. Client must advise IGS of their expectations, as test productivity may sometimes be reduced using this method.

    Objective is best possible pore pressure response in “difficult” ground, but still maintaining modestly high productivity.

    Client might intervene during progress to shift test type to IGS-4C, accepting lower test productivity that results in this shift.


    Typically used at targeted locations after site characterisation by IGS-1 or IGS-2 testing.

    If client wishes to obtain inputs into determination of soil parameters to a “specially” high level he will more likely choose IGS-3C.

    Typical objectives may be assessment of soil properties for design of embankments or preloads over soft to firm and stiffer clay-type foundation soils.

    Dissipation tests should be achieved to a high standard.


    Either and S-Type cone or a C-Type Cone can be used. These are discussed in a following Technical note. 3S denotes an S-Type cone, 3C a C-Type cone. Cone capacity is selected to suit the ground being targeted; eg 100MPa or 25MPa* or 10MPa* (*C-Type only) cone choice is made.

    Pore pressure measurements are closely watched as test progresses. If soil behaviour spoils piezo response in any zones, test penetration is stopped while response monitoring continues.

    If piezo “recovers” in (say) 10-15 minutes test penetration is restarted. If piezo does not “recover” in (say) 10-15 minutes, test penetration might also be started but client accepts consequences of possible zones of reduced pore pressure response. (Note that client can up-grade to IGS-4 if desired).
    IGS-4C Quasi-Research Class Testing.

    Client must be closely engaged in decision process as in extreme conditions test productivity may be quite low using this method.

    Objective is best possible pore pressure response in “difficult” ground, more-or-less regardless of productivity.



    Typically used at targeted locations after site characterisation by IGS-1 or IGS-2 testing.

    Client wishes to obtain inputs into determination of soil parameters to the highest practically achievable level.

    Typical objectives may be assessment of preconsolidation pressure of very soft clays, or assessment of preload progress based on qc or qt parameters.

    Dissipation tests should be achieved to best possible standard.



    Cone capacity is selected to suit the ground being targeted (eg 100MPa or 25MPa or 10MPa cone choice is made). C-Type compression cone is used.

    Pore pressure measurements are closely watched as test progresses. If soil behaviour spoils piezo response in any zones, test penetration is stopped while response monitoring continues.

    If piezo “recovers”, test penetration is re-started.

    If piezo does not “recover”, cone may be pulled out, hole may be water-filled and test may be recommenced with a re-prepped cone.
    "Seis" Seismic CPTu.

    Client must (pre Establishment) Brief IGS on their choice of seismic CPTu. Little or no client involvement is required during testing progress.

    Seismic CPT at IGS is available at present in the form of a 15cm2 C-Type cone.



    Used when the client wants a seismic shear wave velocity profile as well as the usual CPTu (piezo-cone) test outputs.

    Testing can follow any one of the procedures described above for Categories 1C, 3C, or 4C.



    In addition to the processes described above, the CPT push is halted at agreed intervals (typically 0.5m or 1.0m - but can be any) and subjected to a seismic shear wave generated at the ground surface by one of IGS's shear wave hammers. The shear wave signal is recieved by the cone's geophone and processed.
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