6. Determination and Engineering Interpretation of Index Properties

Question 1

Most laboratory index properties are determined using core samples obtained from drilling operations.

Answer 1

Rock Core Sampling

Question 2

Rock Core Sampling Typical Core Sizes

Answer 2

NX core (≈ 54 mm diameter)
HQ core (≈ 63.5 mm diameter)

Question 3

Determination of Porosity

Answer 3

n = Vv/Vt

Question 4

Determination of Density

Answer 4

𝜌 = m/V

Question 5

Determination of Unit Weight

Answer 5

𝛾 = 𝜌𝑔

Question 6

Determination of Water Content

Answer 6

𝑤 = (mw/md)*100

Question 7

• Measures axial compressive strength of intact rock
• Simple but powerful index

Answer 7

Unconfined Compressive Strength (UCS)