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APPENDIX A

RECOMMENDED STANDARD FOR THE CONE PEN-ETRATION TEST (CPT)

CONTENTS

1.    SCOPE

2.    DEFINITIONS

2.1    CPT definition

2.2    Penetrometer

2.3    Penetrometer tip

2.4    Cone

2.5    Friction sleeve

2.6    System of measurement

2.7    Push rods

2.8    Inner rods

2.9    Thrust machinę

2.10    Friction reducer

2.11    Continuous and discontinuous pen-etration testing

2.12    Cone resistance

2.13    Local side friction

2.14    Total force

2.15    Total side friction

2.16    Friction ratio and friction index

3.    RECOMMENDED STANDARD PENETROMETER

3.1    General geometry of tip

3.2    The cone

3.3    Gap and seal above the cone

3.1    Sensing device 3-5 Friction sleeve

3.6    Push rods

3.7    Measuring equipment

3.8    Thrust machinę

3.9    Friction reducer

A. STANDARD TESTING PROCEDURĘ

4.1    Continuous testing

4.2    Verticality

4.3    Ratę of penetration A.U Interval of reading

A.5 Measurement of the depth

5.    PRECISION OF THE MEASUREMENTS

6.    PRECAUTIONS, CHECKS AND VERIFICATIONS

7.    CALIBRATION

8.    SPECIAL FEATURES

8.1    Push rod guides

8.2    Inclinometers

8.3    Push rods with smaller diameters

9.    REPORTING OF RESULTS

9.1    Basic data

9.2    Internal data

9.3    Scales recommended

9.4    Site plan

9-5 Additional data

10. DIVERGENCES FROM THE RECOMMENDED STANDARD

10.1    General

10.2    Dimensions and shape of the cone

10.3    Location and dimensions of the friction sleeve

10.4    Discontinuous testing with free cone penetrometer tips

10.5    Table of traditional penetrometer tips diverging from the Standard

10.6    Precision of the measurements

10.7    Static dynamie penetrometers and pre-

boring cone penetrometers

10.8 Precautions, checks and verifications

11. EXPLANATORY NOTES AND COMMENTS 1. SCOPE

The cone penetration test consists in pushing into the soil, at a sufficiently slow ratę, a series of cylindrical rods with a cone at the base, and measuring continuously or at selected depth intervals the penetration resistance of the cone, and if required the total penetration resistance and/or the friction resistance on a friction sleeve.

Cone penetration tests are performed in order to obtain data on one or morę of the follow-ing subjects:

1)    the stratigraphy of the layers, and their homogeneity over the site

2)    the depth to firm layers; the location of cavities, voids and other discontinuities

3)    soil Identification

4)    mechanical soil characteristics

5)    bearing capacity of piles 2. DEFINITIONS

2.1 CPT stands for Cone Penetration Test and includes what has been variously called Static Penetration Test, Quasi Static Penetration Test and Dutch Sounding Test.

2.2 Penetrometer (apparatus): an apparatus consisting of a series of cylindrical rods with a terminal body, called the penetrometer tip and the measuring devices for the deter-mination of the cone resistance, the local side friction and/or the total resistance.

2.3 Penetrometer tip.

2.3.1    Penetrometer tip proper: the terminal body at the end of the series of push rods, which comprises the active elements that sense the cone resistance, and the local side friction resistance.

2.3.2    Conventional penetrometer tip: by convention, if the length of the part of the penetrometer tip proper located above the cone is smaller than 1000 mm, the push rod length to be added to the length of the penetrometer tip in order to obtain a length of 1000 mm.

2.4 Cone: the part of the penetrometer on which the end bearing is developed.

According to the design of the apparatus the following are distinguished:

2.4.1 Fixed cone penetrometer tip: the cone can only be subjected to micro relative dis-

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