CONE PENETRATION TEST

Question 1

it is originally known as Dutch cone penetration test

Answer 1

cone penetration test

Question 2

Cone penetration test is a versatile ___________ test that can be carried out in most soil conditions.

Answer 2

in situ

Question 3

The original Dutch cone penetration test developed in _______________ in 1932 was a _____ degree mechanical cone with a ______ mm outside diameter, with approximately _____ cm^2 projected area.

Answer 3

Holland, 60, 35, 10

Question 4

When a cone is pushed to the ground, the resistance at the cone, known as the __________ and the ____________ is measured separately.

Answer 4

cone resistance (qc). sleeve friction (fc)

Question 5

____________________ is the force required to push the cone tip into the soil per unit cross-sectional area.

Answer 5

Cone Resistance

Question 6

Standard CPT tests use a rate of _____ mm/s.

Answer 6

20

Question 7

In CPT with piezocone (CPTu), what does the pore pressure sensor measure?

Answer 7

The pressure of water within the soil pores during penetration

Question 8

In Dutch penetration test, the measurement is recorded at larger intervals in the order of ________ mm

Answer 8

200

Question 9

Electrical cone measurements are made using ________________ and ______________ generally for every 20 mm.

Answer 9

strain gauges, transducers

Question 9

Who developed the first electric cone in 1965 as an improvement to the mechanical cone.

Answer 9

Fugro

Question 10

_____________ is the resistance measured along the friction sleeve of the CPT probe as it penetrates the soil. It is an important parameter used to determine soil type and estimate ______________.

Answer 10

Sleeve friction, shear strength

Question 11

Helps distinguish between cohesive (clay) and non-cohesive (sand) soils.

Answer 11

Sleeve Friction

Question 12

Used to determine undrained shear strength of clay.

Answer 12

Sleeve Friction

Question 13

The modern cones which are also able to measure pore water pressure, are known as ______________

Answer 13

piezocones

Question 14

The standard cone of _____ cm^2 has a friction sleeve area of ________ cm^2

Answer 14

10, 150

Question 15

The __________ mm long frictional sleeve has an outer diameter of ________ mm.

Answer 15

133.7, 35.7

Question 16

______________ are the modern electric friction cones. With the addition of sensors such as geophones, seismic cone penetration tests can now also measure shear wave velocity vs, and hence the ________________.

Answer 16

Piezocones, shear modulus G

Question 17

A _____________ pushes the cone into the ground

Answer 17

hydraulic ram

Question 18

High sleeve friction in a Cone Penetration Test (CPT) typically indicates that the soil has a significant amount of ________.

Answer 18

cohesion

Question 19

________ friction ratio = More clay, silt, or organic soil

Answer 19

High

Question 20

_________friction ratio = More sand or gravel

Answer 20

Low

Question 22

Friction ratio varies in the range of 0- ___ %, with the lower end of the range for ________ soil and the upper end for ________ soil.

Answer 22

10, granular, cohesive

Question 23

The friction ratio varies in the rang of 0 - ___% with the lower end of the range for ________ soil and the upper end for ________ soil.

Answer 23

10, granular, cohesive

Question 24

In a recent study on several soil in Greece, Anagnostopoulos et al expressed Fr as ____________________ for electric cone

Answer 24

Fr = 1.45-1.36 log (D50)

Question 25

In a recent study on several soil in Greece, Anagnostopoulos et al expressed Fr as ____________________ for mechanical cone.

Answer 25

Fr = 0.7811 - 1.611 log (D50)

Question 26

Kulhawy and Mayne (1990) proposed the following relationship to correlate Dr, qc, and the vertical effective stress (O'o): In this equation, OCR = overconsolidation ratio pa= _______________________ Qc = _______________________ The recommended values of Qc are as follows: Highly compressible sand = _____ Moderately compressible sand = 1.0 Low compressible sand = ____

Answer 26

Dr = Sqr ( (1/305 (Qc) (OCR)^1.8)((qc/pa)/(O'o/pa)^0.5)) atmospheric pressure compressibility factor 0.91 1.09

Question 27

The precding relationship between Dr, qc pa, and O'o can be rewritten as

Answer 27

Dr(%) = 68(log (qc/sqr(pa * O'o)) - 1)

Question 28

On the basis of experimental results, Robertson and Campanella (1983) suggested the variation of Dr, O'o, and drained friction angle for normally consolidated quartz sand. This relationship can be expressed as (Kulhawy and Mayne, 1990)

Answer 28

drained friction angle = tan-1 ( 0.1 + 0.38 log (qc/O'o)

Question 29

Based on the cone penetration tests on the soil in the Venice Lagoon (Italy), Ricceri et al. (2002) proposed a similar relationship for soil with classifications of ML and SP-SM fro correlation between qc and drained fricion angle for sand

Answer 29

drained friction angle = tan-1 (0.38 + 0.27 log (qc/O'o))

Question 30

Lee et al. (2004) developed a correlation among drained friction angle, qc, and the horizontal effective stress (O'h) in the form

Answer 30

drained friction angle = 15.575 (qc/O'h)^0.1714

Question 31

The undrained shear strength, cu, can be expressed as Nk = Mayne and Kemper Nk (electric) = ______________ Nk (electric) = ______________ Greece Nk (electric)= ____________ Nk (mechanical) = ______________ These field tests also showed that Cu (mechanical) = Cu (electrical) =

Answer 31

cu = (qc -Oo)/Nk bearing capacity factor 15 20 17.2 18.9 Cu= fs/1.26 (mechanical) Cu = fs (electrical)

Question 32

Mayne and Kemper (1988) provided correlations for preconsolidation pressure (sc9) and overconsolidation ratio (OCR) as O'c = ? OCR =?

Answer 32

O'c = 0.243 (qc)^0.96 OCR = 0.37 ( (qc-Oo)/O'o)^1.01