Subchapter 17. Mine Safety Orders
Article 12. Ground Control

§6985. (3-1). Excavations of Sand, Gravel and Similar Material.

(a) Excavations in sand, gravel, or other material shall be sloped to an angle at which employees will not be endangered by falling or sliding materials.

(b) When determining the maximum permitted slope of the face, consideration shall be given to:

(1) Nature of the material being excavated.

(2) Extent to which the material is cemented or consolidated.

(3) Height of the face.

(4) Type and size of equipment used at the face and amount of protection this equipment affords the operator.

(5) Safety of employees who are not protected by such equipment.

(c) Where the face is composed of loose or unstable materials, the slope of the face shall not exceed 50 degrees where the height is greater than can be reached by the dipper or bucket of the excavator or loader being used.

(d) Where the face is composed of moderately compacted materials that are not firmly cemented or consolidated but which experience indicates will stand well in place, the slope shall not exceed 65 degrees where the height is greater than can be reached by the dipper or bucket of the excavator or loader being used.

(e) Where the face is composed of firmly cemented or consolidated materials that experience indicates do not shall or cave readily, the slope shall not exceed 80 degrees where the height is greater than can be reached by the dipper or bucket of the excavator or loader being used.