Details

What is Cone Penetration Testing?

Cone Penetration Testing uses a cylindrical cone pushed vertically into the ground at a constant rate of penetration of 20mm per second. During penetration, measurements are made of the cone resistance, the side friction against the cylindrical shaft and in Piezocone tests, the pore water pressure generated at penetration by the cone.

The measurements are made and recorded using electrical devices. The frequency of the 25mm reading provides a detailed picture of the variation of the measured parameters with penetration depth.

Cone penetration testing is used:

to determine types of soil and identify materials present
to estimate Geotechnical parameters
to provide results for direct Geotechnical design

Vibrating Wire Piezometers

Probedrill can install vibrating wire piezometers to a requested depth in a timely manner without the need for costly borehole construction.

An initial probe is conducted to determine the soil structure and the required depth of the VW piezometer. A disposable cone is used to push the VW piezometer to the required depth using the CPT rigs. The VW piezometers can then be back filled with sand and bentonite to ensure it maintains the correct depth for operation.

Seismic Electronic Cone Penetrometer

Using a Seismic Electronic Cone Penetrometer it is possible to measure down-hole shear wave propagation speed during cone soundings. A Seismic test is performed at given depths of probing, testing from both the left and right side of the Seismic cone, to achieve a higher accuracy. Performing this measurement during CPT probing is much quicker and less expensive that standard cross-hole tests or down-hole tests. Graphs showing the results of the testing are produced using Coreview software. The Seismic graphs show the Seismic Shear Wave Test results (Left and Right) and the Seismic Delay and Velocity (Left and Right). All Probedrill CPT Rigs are able to provide Seismic testing.

DMT (Dilatometer Testing)

A Dilatometer Test (DMT) consists of pushing flat blade into the soil, to a desired depth using a CPT rig. Once the test depth is reached, a circular steel membrane located on one side of the blade is expanded horizontally into the soil, the operator records two pressures (A and B pressures)

The pressure A is the pressure on the blade before expansion while the pressure B is the pressure required to produce an expansion of 1mm of the membrane into the soil. The operator then deflates the membrane and records a third pressure (C pressure). The C test requires about 1-2 minutes, and is optional. The blade is then advanced to the next test depth.

Graphs are then produced which show Dilatometer Modulas (ED), Constrained Modulas (M), Material Index (Clay, Silt, Sand), Horizontal Stress (KD), Undrained Sheer Strength (Su), and Corrected C readings (P2) (if C readings are taken).

The dilatometer is particularly sensitive and therefore useful to evaluate such factors as stress state/history, aging, cementation, and structure. DMT testing is mainly used to accurately predict settlement of shallow foundations, both in sands and clays, and to determine the undrained shear strength in clay. It can also be used for determine slip surfaces in slopes & resistivity to liquefaction

For more information on DMT testing read: http://www.marchetti-dmt.it/pdffiles/totani_bali2001.pdf

or visit

http://www.marchetti-dmt.it

SAMPLE PLOTS

E.F.C.P. Testing (Electric Friction-Cone Pentrometer)

Tip Resistance, Friction Sleeve, Friction Ratio
	CP2636 (54 KB)
	CP2637 (55 KB)
	GA1080M (37 KB)
	ME0004m (46 KB)

Pore Pressure, Dissipation
	CP2637aa (38 KB)
	HA0107a *with R.L (31 KB)
	ME0004ma (29 KB)

2 x Tip Resistance, Friction, Friction Ratio
	CP2682 (54 KB)
	GA6173 (59 KB)
	HA0107 *with R.L (57 KB)

Seismic Testing
	CP2636 (left 1) (188 KB)
	CP2636 (left 2) (26 KB)
	CP2636 (right 1) (186 KB)
	CP2636 (right 2) (26 KB)

	CP2682 (left 1) (69 KB)
	CP2682 (left 2) (26 KB)
	CP2682 (right 1) (69 KB)
	CP2682 (right 2) (26 KB)

Dilatometer Test (DMT)
	WA0465 DMT 1a (1) (38 KB)
	WA0465 DMT 1a (2) (36 KB)
	WA0465 DMT 1a (3) (24 KB)
	WA0465 DMT 1a (4) (18 KB)

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