What is the difference between 'rock' and 'rock mass' as per this code?

'Rock' refers to the intact, unfractured material, while 'Rock Mass' describes the in-situ rock body, including its structural discontinuities like joints, faults, and bedding planes (Clause 2).

How is Rock Quality Designation (RQD) defined?

RQD is defined as the percentage of intact core pieces longer than 100 mm over the total length of the core run. It is a quantitative index of rock mass quality (Clause 2).

What is the definition of 'dip' and 'strike'?

'Strike' is the direction of the line of intersection of a planar feature (like a joint or bed) with a horizontal plane. 'Dip' is the maximum angle of inclination of that planar feature, measured perpendicular to the strike (Clause 2).

Does this standard provide methods for rock testing?

No, IS 11358 is a glossary. Methods for testing rock properties are covered in other standards like IS 9143 (Uniaxial Compressive Strength) and IS 10050 (Point Load Strength).

IS 11358

: 1987

Glossary of terms and symbols relating to rock mechanics

CurrentFrequently UsedTerminologyBIMGeotechnical · Rock Mechanics

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This standard provides a comprehensive glossary of terms and a list of symbols commonly used in the field of rock mechanics. It serves as a foundational document to standardize terminology and communication among engineers and geologists working on projects involving rock masses.

Glossary of terms and symbols relating to rock mechanics

Practical Notes

This is an essential reference for understanding technical terminology in geotechnical investigation reports for rock.

It helps in clearly distinguishing between properties of intact rock and the rock mass, which is a common point of confusion.

While it provides standard symbols, always cross-check with international ISRM (International Society for Rock Mechanics) recommendations which are also widely used.