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1. WALCHAND COLLEGE OF ENGINEERING, SANGLI
Department of Civil Engineering
Foundation Engineering Laboratory
CONE PENETRATION TEST
Presented by
Vinay Vitekari – 22110029
Gaurav Rathod – 22110037
Anvesha Wadar – 22110040

2. Contents
• Introduction to CPT test
• History and Development
• Instruments Used in CPT test
• Types of CPT Equipments
• Principle of CPT test
• Procedure of CPT test
• Interpretation of Results of CPT test
• Advantages & Limitations of CPT test
• Application of CPT test
• Conclusion

3. Introduction to CPT
• CPT is the currently most used and accepted in-situ test method for soil
investigation world wide.
• It is used in Geotechnical engineering to determine engineering properties of
soils which involves the pushing of cone shaped probe into the soil at a
constant rate and measuring the resistance
• It was used in 1950s at the Dutch Lab for soil Mechanics so that it also has
been called the Dutch cone test

4.  History & Development
• First Developed in the Netherlands as a mechanical cone in
1930s.
• Electric cones are developed in 1960’s.
• Standardized as per ASTM D5778 and ISO 22476-1.
• Used worldwide for foundation design, soil stratification, and
liquefaction assessment.

5.  Equipment Used
• CPT Rig: A heavy vehicle or truck-mounted system that provides
hydraulic force or it can be hand operated.
• Steel Cone with a 60° apex angle and base area of 10 cm² or 15
cm².
• Friction Sleeve: Measures side friction during penetration.
• Push Rods: Drive the cone into the soil.
• Data Acquisition System: It includes the computer system which
Records cone resistance, sleeve friction, and pore water
pressure (if piezo cone is used).
• Some of Cones are equipped with a geophone in order to
perform shear wave velocity measurements.

6.  Types of CPT Equipment
• Mechanical CPT: Uses a cable to measure resistance.
• Electric CPT: Sensors inside the cone provide more accurate readings.
• Seismic CPT: Measures shear wave velocity for earthquake studies.
• Piezocone CPT (CPTu): Measures pore water pressure for soil permeability.
Engine Operated (200KN) Hand Operated (30KN)

7. Typical Cone Sizes :
• It includes the range of cones from a mini cone at 2cm2 to a
large cone of 40cm2.
• The mini cones are used for shallow investigations, whereas
the large cones can be used in gravely soils.

8.  Principle of CPT :
• The CPT works on the principle of penetration resistance.
• A cone is pushed into the soil at a standard penetration rate of
2 cm/sec, and resistance is measured.
Key Parameters measured from CPT Test :
• Tip or Cone Resistance (qc): Measures resistance at the cone
tip, indicating soil strength.
• Sleeve Friction (fs): Measures friction along the sleeve, helping
classify soil type.
• Pore Water Pressure (u): Measured in Piezo cone(if used) tests
(CPTu) to assess drainage and soil permeability.

9.  Procedure of CPT Test :
Step-by-Step Process
• Site Preparation: The CPT rig is positioned on the test site.
• Cone Insertion: The cone is pushed into the soil at a constant rate
(2 cm/sec).
• Data Collection:
• Tip resistance (qc) and sleeve friction (fs) are measured.
• Piezo cone tests also measure pore water pressure (u).
• Depth Measurement: The test is conducted to the required depth.
• Data Interpretation: Readings are analyzed to classify soil and
determine geotechnical properties.

11. CPT Test Results Example

12.  Interpretation of Results
CPT results help in
• Soil classification (based on fs/qc ratio).
• Estimating un-drained shear strength in clayey soils.
• Determining relative density in sandy soils.
• Assessing liquefaction potential (using pore pressure readings).
Soil behavior charts are used to correlate CPT data with engineering
properties.

14. Advantages of CPT
• Fast and efficient compared to standard
penetration test (SPT).
• Economical
• Provides continuous data for better soil
profiling.
• Less soil disturbance compared to borehole
sampling.
• Can be used in soft soils where SPT may not
works well.
• Real Time measurements can be taken.
Limitations of CPT
• Not suitable for gravels or hard rock.
• Requires specialized equipment and
trained operators.
• Cannot provide soil samples for
laboratory testing.
• Equipment can get damaged in dense
soil layers.
• Penetration Depth is limited up to 150 -
200 ft.

15.  Applications of CPT
CPT is used in:
• Foundation design (determining load-bearing capacity of soil).
• Pile design (assessing pile installation depth and capacity).
• Slope stability analysis(identifying weak soil layers which are prone to
landslides).
• Liquefaction assessment (evaluating earthquake hazards).
• Environmental site investigations (detecting soil contamination).

16.  Conclusion
• CPT is a reliable and efficient method for geotechnical investigation.
• Continuous technological advancements make CPT an indispensable
method for modern geotechnical projects.
• It Provides continuous, accurate soil data for engineering applications.
• It is widely used for foundation design, soil classification, and
liquefaction assessment.
• In normally consolidated or recently aged cohesion less soils,
it provides good estimates of settlement for shallow foundations.