What determines the method used for quarrying stone?

The type of stone, its geological formation, and its intended end-use. Blasting is for aggregates, while non-blasting methods are for dimensional stone (Clause 4.1).

What are the key safety rules for a quarry face?

The face must be kept free of loose, overhanging rock, and the overall slope should generally not exceed 60 degrees from the horizontal (Clause 5.1).

When should blasting be avoided?

Blasting should be avoided for stones that are soft, stratified, or intended for ornamental work, as the shock can cause fractures and render the stone useless (Clause 4.3.1).

What is the difference between burden and spacing in blasting?

Burden is the distance from the blast hole to the nearest free face, while spacing is the distance between adjacent blast holes in the same row (as defined in IS 6609).

IS 8381

: 1977

Recommended practice for quarrying stones for construction purposes

CurrentSpecializedCode of PracticeGeotechnical · Stones

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This standard provides recommended practices for quarrying natural stones for construction purposes. It covers aspects like site investigation, quarrying methods (including manual, mechanical, and blasting techniques), and critical safety precautions during operations.

Recommended practice for quarrying stones for construction purposes

Quick Reference Values

Maximum bench height for manual quarrying1.5 m

General maximum overall slope of quarry face60 degrees from horizontal

Typical blast hole spacing to burden ratio0.8 to 1.2

Minimum distance for storing explosives from working area100 m

Recommended slope of quarry benchesNearly horizontal or slightly sloping towards the face

Practical Notes

The choice of quarrying method (blasting vs. non-blasting) is critical. Blasting is unsuitable for ornamental or dimensional stones as it induces micro-cracks, affecting strength and appearance.

Strict adherence to safety protocols in Clause 5 and IS 4081 is paramount, especially regarding handling of explosives and maintaining stable quarry faces.

Thorough site investigation as per Clause 3 is essential to determine the economic viability and quality of the stone deposit before major investment.