Cone Penetration Test

MoDOT moving in to the future .

Cone Penetration Test (CPT)

• A method used to determine the Geotechnical

properties of soils and delineating soil

stratigraphy.

CPT Program @ MoDOT

• The program got started

in 1997.

• The main goal was to

use digital technology

to accurately determine

geotechnical properties

of soils.

• To accurately predict

static resistance of a

driven pile using both

tip and sleeve

resistance to derive

this.

• To be used alternative

to Standard Penetration

Test (SPT).

SPT VS CPT

• Its fair to say that CPT provides a better soil

characterization than SPT. When no

improvements are made to the current SPT

method, with all its variations and

uncertainties , the split spoon should be

placed in the same cabinet as the slide rule

and the fax machine.

SPT VS CPT

Use in Missouri:

• Southeast District – Bootheel of Missouri

• Counties - 7

• Bridge Count – 697

• Geology – Quaternary System (>250’ of sand)

SPT VS CPT

SPT

• Very messy process

• Long turnaround time

• Inaccurate blow counts

• Operator errors

CPT

• No Bentonite required

• Quicker turnaround time

• Accurate blow counts

• Minimized operator errors

SPT VS CPT

Mud Rotary Drilling Mud Rotary Drilling

CPT Equipment (Past)

• CME 850

CPT Equipment (Past)

• Rod Push System

CPT Equipment (Past)

Anchors Rod Basket

CPT Equipment (Past)

Old Beams Hammer

CPT Equipment (Past)

• Old Computer

CPT Equipment (Past)

• Old Computer in Jeep

Equipment (Current)Hogentogler Track-

Mounted Rig.

Push Capacity – 10

Ton

Pull Capacity - 15

Ton

Power - 29 Hp diesel

Manufacture - Vertek

(Hogentogler)

Classification - Light

Hydraulic Power

Auger System.

Equipment (Current)

Equipment (Current)

• Computer and Truck Box

Software

• Hogentogler - Digital Cone Plot

• Geologismiki – Cone Data Analysis

• gINT – Cone Boring Plots & Data Stroage

Software

• Hogentogler

• Digital Cone Plot – Data Acquisition software

for the cone. Plots are quickly generated and

output in tabular form for use with other

programs.

Software

• Geologismiki (Analysis)

• CPET-IT – Bearing Capacity, Settlement Calc ,

Pile Calc., Dissipation Interpretation.

• CLiq – Liquefaction, Settlement Analysis.

• Liq SV – Liquefaction (calculation using blow

counts N60 as raw data).

• StoneC – Stone columns.

Software

• gINT – Geotechnical and Geoenvironmental

software

• Used to produce boring plots.

• Used to store cone data.

• Used to archive information.

Software

• Old Seismic Log • Old Log

Software

• Old Log • Old Log

Software

New Outputs

• Bearing Capacity • Pile Capacity Graph

Software

• LPile Sheet • Liquefaction

Future

• Geoprobe 2060 CPT • Vertek Track Base

System

QUESTIONS?