Holooly Plus Logo
Holooly Plus Logo

Question 9.9: Static cone penetration test at a site at depth of 30 ft rev...

Static cone penetration test at a site at depth of 30 ft revealed the following

Cone resistance q_{c}=125 tsf

Friction ratio R_{f}=1.3 \%

The average effective unit weight of the soil is 115 psf. Classify the soil per Fig. 9.16.

The Blue Check Mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

The effective overburden pressure p_{0}^{\prime}=30 \times 115=3450 lb / ft ^{2}=1.725 tsf

 

From Eq (9.15)

 

q_{c n}=q_{c}\left(1-1.25 \log p_{o}^{\prime}\right) (9.15)

 

q_{c n}=125(1-1.25 \log 1.725)=88 tsf

 

R_{f}=1.3 \%

 

From Fig. 9.16, the soil is classified as sand to silty sand for q_{c n}=88 tsf \text { and } R_{f}=1.3 \%

Related Answered Questions

The static cone penetration resistance at a site at 10 m depth is 2.5 MN/m^2. The friction ratio obtained from the test is 4.25%. If the unit weight of the soil is 18.5 kN/m^3, what type of soil exists at the site.

Verified Answer:
\begin{aligned}q_{c} &=2.5 \times 1000 ...

If a deposit at a site happens to be a saturated overconsolidated clay with a value of qc = 8.8 MN/m^2, determine the unconfmed compressive strength of clay given p0 = 127 kN/m^2

Verified Answer:
Per Eq (9. 14)   q_{c}=N_{k} c_{u}+p_{...

Static cone penetration tests were carried out at a site by using an electric-friction cone penetrometer. The following data were obtained at a depth of 12.5 m. cone resistance qc = 19.152 MN/m^2 (200 tsf) friction ratio Rf = fc/qc = 1.3 Classify the soil as per Fig. 9.16. Assume γ(effective) =16.5

Verified Answer:
The values of q_{c}=19.152 \times 10^{3} kN...

A pressuremeter test was carried out at a site at a depth of 7 m below the ground surface. The water table level was at a depth of 1.5 m. The average unit weight of saturated soil is 17.3 kN/m^3. The corrected pressuremeter curve is given in Fig. Ex. 9.11 and the depleted volume of the probe is Vc

Verified Answer:
From Fig. Ex 9.11, p_{o h}=p_{o m}=105[/lat...

A seismic survey was carried out for a large project to determine the nature of the substrata. The results of the survey are given in Fig. Ex 9.12 in the form of a graph. Determine the depths of the strata.

Verified Answer:
Two methods may be used 1. Use of Eq (9.35)  ...

The following dimensions are given for a shelby tube sampler: External diameter = 51 mm Internal diameter = 48 mm Determine the area ratio

Verified Answer:
Per Eq (9.1) the area ratio A_{r} i...

75 mm is the external diameter of a sampling tube. If the area ratio required is 20%, determine the thickness of the sampling tube. In what type of clay would such a high area ratio be required?

Verified Answer:
A_{r}=\frac{75^{2}-d_{i}^{2}}{d_{i}^{2}}=0....

The observed standard penetration test value in a deposit of fully submerged sand was 45 at a depth of 6.5 m. The average effective unit weight of the soil is 9.69 kN/m^3. The other data given are (a) hammer efficiency = 0.8, (b) drill rod length correction factor = 0.9, and (c) borehole correction

Verified Answer:
Per Eq (9.6), the equation for N _{60}[/lat...

For the corrected N values in Ex 9.3, determine the (a) relative density, and (b) the angle of friction. Assume the percent of fines in the deposit is less than 5%.

Verified Answer:
Per Table 9.3 the relative density and \phi...

For the corrected values of N given in Ex 9.4, determine the unconfined compressive strength qu in a clay deposit.

Verified Answer:
(a) From Table 9.4   \left.\begin{matr...