A method of testing soils by pressing a cone of standard dimensions into the soil under a known load and measuring the penetration. (extensive investigation and research in construction site).

1. Prepared By : Mohd. Ikhwan Bin Abdullah
Matric No. : 2006121149

2. ContentContent
 Background information
 Use of Cone Penetration Test (CPT)
 Equipment used in CPT
 Process of CPT
 Advantage & Disadvantage
 Conclusion

3.  CPT nowadays is the most used and accepted in-
situ test methods for soil investigation world wide.
 It is to determine the GEOtechnical engineering
properties of soils.
 It was initially used in 1950s at the Dutch Lab for
soil Mechanics so that it has also been called the
“Ducth cone test”.

4.  CPT are conducted to measure and evaluate
characteristics of certain soils (soft sensitive silts
and clays and some coarse cohesionless soils)
such as:
i) Stratification
ii) Soil type
iii) Relative soil density and in-situ stress
conditions
iv) Shear strength parameters

5.  After analysing the results obtained from the test,
we can determine the soil type and design of
shallow foundations through the estimation of
stiffness and shear strength of cohesive soils.
 The results from CPT may also be used, directly,
for design of piled foundations in sand and gravel.
 Indirectly, it can be used (shear strength) for piles
in clay.

6.  CPT device consists in:
- a cylindrical probe with a cone-shaped tip
(having a cross-sectional area of either 10 or
15cm², corresponding to diameters of 3.6 and 4.4
cm).
- The cone, which has an apex angle of 60º is
attached to a rod, this latter being protected by an
outer sleave.
- Some of them are equipped with a geophone in
order to be able to perform shear wave velocity
measurements.

7. - The data is normally read by a field computer
that displays it real-time and stores it at regular
depth intervals.

8.  A 60º cone with face area
10cm² and 150cm² friction
sleeve is hydraulically
pushed into the ground
(the device is pushed,
rather than being driven
by blows, into the soil).
 By applying a measure
force to the rod, the cone
is pushed into the soil at a
constant speed of
penetration (ranging form
1.5 to 2.5cm/s).
Figure 2.0 : Cone Penetration Test

9. Advantage Disadvantage
Rapid and inexpensive
Reproducible result
Real time measurement
Accurate, detailed subsurface
stratigraphy / identification of problem
soils
No sample recovered
Penetration depth limited to 150 –
200 feet
Normally cannot push through gravel
Requires special equipment and
skilled operator

10.  Save money for the owner by more accurately
identifying the geological strata.
 Seismic evaluations can be done to satisfy the
new building code requirements by measuring the
low strain shear wave velocity.
 Can be used to predict vertical pile capacity.
 In normally consolidated or recently aged
cohesionless soils, provides good estimates of
settlement for shallow foundations.