Approved Plan - EXE230029

            Cone Penetrometer Testing (CPT) and Interpretation:                       There are limitations when using the CPT in that it may not penetrate
            The cone penetrometer is sometimes referred to as a Dutch Cone.           obstructions within any fill, thick layers of hard clay and very dense
            The test is described in Australian Standard 1289.6.5.1–1999 (R2013)      sand, gravel and weathered bedrock. Normally a ‘dummy’ cone is
            ‘Methods of Testing Soils for Engineering Purposes, Soil Strength and     pushed through fill to protect the equipment. No information is
            Consolidation Tests – Determination of the Static Cone Penetration        recorded by the ‘dummy’ probe.
            Resistance of a Soil – Field Test using a Mechanical and Electrical
            Cone or Friction-Cone Penetrometer’.                                      Flat Dilatometer Test: The flat dilatometer (DMT), also known as the
                                                                                      Marchetti Dilometer comprises a stainless steel blade having a flat,
            In the tests, a 35mm or 44mm diameter rod with a conical tip is
                                                                                      circular steel membrane mounted flush on one side.
            pushed continuously into the soil, the reaction being provided by a
            specially designed truck or rig which is fitted with a hydraulic ram      The blade is connected to a control unit at ground surface by a
            system. Measurements are made of the end bearing resistance on            pneumatic-electrical tube running through the insertion rods. A gas
            the cone and the frictional resistance on a separate 134mm or             tank, connected to the control unit by a pneumatic cable, supplies
            165mm long sleeve, immediately behind the cone. Transducers in            the gas pressure required to expand the membrane. The control unit
            the tip of the assembly are electrically connected by wires passing       is equipped with a pressure regulator, pressure gauges, an audio-
            through the centre of the push rods to an amplifier and recorder unit     visual signal and vent valves.
            mounted on the control truck. The CPT does not provide soil sample
                                                                                      The blade is advanced into the ground using our CPT rig or one of our
            recovery.
                                                                                      drilling rigs, and can be driven into the ground using an SPT hammer.
            As penetration occurs (at a rate of approximately 20mm per second),       As soon as the blade is in place, the membrane is inflated, and the
            the information is output as incremental digital records every 10mm.      pressure required to lift the membrane (approximately 0.1mm) is
            The results given in this report have been plotted from the digital       recorded. The pressure then required to lift the centre of the
            data.                                                                     membrane by an additional 1mm is recorded. The membrane is then
                                                                                      deflated before pushing to the next depth increment, usually
            The information provided on the charts comprise:
                                                                                      200mm down. The pressure readings are corrected for membrane
             Cone resistance – the actual end bearing force divided by the           stiffness.
                cross sectional area of the cone – expressed in MPa. There are
                two scales presented for the cone resistance. The lower scale         The DMT is used to measure material index (ID), horizontal stress
                has a range of 0 to 5MPa and the main scale has a range of 0 to       index (KD), and dilatometer modulus (ED). Using established
                50MPa. For cone resistance values less than 5MPa, the plot will       correlations, the DMT results can also be used to assess the ‘at rest’
                appear on both scales.                                                earth pressure coefficient (Ko), over-consolidation ratio (OCR),
             Sleeve friction – the frictional force on the sleeve divided by the     undrained shear strength (Cu), friction angle (), coefficient of
                surface area – expressed in kPa.                                      consolidation (Ch), coefficient of permeability (Kh), unit weight (),
                                                                                      and vertical drained constrained modulus (M).
             Friction ratio – the ratio of sleeve friction to cone resistance,
                expressed as a percentage.                                            The seismic dilatometer (SDMT) is the combination of the DMT with
                                                                                      an add-on seismic module for the measurement of shear wave
                The ratios of the sleeve resistance to cone resistance will vary
                                                                                      velocity (Vs). Using established correlations, the SDMT results can
                with the type of soil encountered, with higher relative friction in
                                                                                      also be used to assess the small strain modulus (Go).
                clays than in sands. Friction ratios of 1% to 2% are commonly
                encountered in sands and occasionally very soft clays, rising to
                                                                                      Portable Dynamic Cone Penetrometers: Portable Dynamic Cone
                4% to 10% in stiff clays and peats. Soil descriptions based on
                                                                                      Penetrometer (DCP) tests are carried out by driving a 16mm
                cone resistance and friction ratios are only inferred and must not
                                                                                      diameter rod with a 20mm diameter cone end with a 9kg hammer
                be considered as exact.
                                                                                      dropping 510mm. The test is described in Australian Standard
            Correlations between CPT and SPT values can be developed for both         1289.6.3.2–1997 (R2013) ‘Methods of Testing Soils for Engineering
            sands and clays but may be site specific.                                 Purposes, Soil Strength and Consolidation Tests – Determination of
            Interpretation of CPT values can be made to empirically derive            the Penetration Resistance of a Soil – 9kg Dynamic Cone
            modulus or compressibility values to allow calculation of foundation      Penetrometer Test’.
            settlements.                                                              The results are used to assess the relative compaction of fill, the
            Stratification can be inferred from the cone and friction traces and      relative density of granular soils, and the strength of cohesive soils.
            from experience and information from nearby boreholes etc. Where          Using established correlations, the DCP test results can also be used
            shown, this information is presented for general guidance, but must       to assess California Bearing Ratio (CBR).
            be regarded as interpretive. The test method provides a continuous        Refusal of the DCP can occur on a variety of materials such as
            profile of engineering properties but, where precise information on       obstructions within any fill, tree roots, hard clay, gravel or ironstone,
            soil classification is required, direct drilling and sampling may be      cobbles and boulders, and does not necessarily indicate rock level.
            preferable.




            February 2019                                                       3



Document Set ID: 22532435
Version: 1, Version Date: 07/08/2023