Of practical interest is the establishment by calculation of the dependence of the uniaxial compression strength on the stable parameters of strength and deformation properties of rocks and the size of samples ...

It is known that rock in the sides of horizontal workings is destroyed either by shear along one or another sliding surface or by detachment of the near-contour zones of the rock mass along vertical surfaces. Failure by shear is well explained from the standpoint of the theory of limit equilibrium of a cohesionless medium. The second possible type of failure — detachment of near-contour zones — has so far no clear explanation.

Wooden rods, which usually have a wedge‑slot construction and possess low weight, low cost, ease of manufacture, non‑scarcity of material, are still rarely used. The reasons for this are the low bearing capacity of the deep lock of such rods, not exceeding 1‑1.5 t, short service life and low resistance to shear forces. ...

The proposed calculation method is valid for spacer-type rod locks with non-linked spacer segments. However, similar relationships can be derived for other designs of metal rod locks of the spacer type. In this case, the actual contact surface of the rod lock with the rock, which has a curvilinear outline, should be reduced to an equivalent rectangular surface in plan, and half the length of this fictitious surface should be substituted into formula (6) instead of half the length of the die surface.