Nowadays, most of the rock pillar design methods have as a normal procedure the considerations of the scale effects between the laboratory tests results and the in situ parameters to be considered for behavior of the rock pillar prediction. Therefore, the authors of this paper have observed that the conclusions of the studies that induced the formulation of these methods, have taken in account the obtained data over models and theoretical laboratory works. The authors agree that the FS (Factor of Safety) is a good and previous indication of the pillar behavior. The Tributary Area concept states that this factor should be obtained by the forces equilibrium relation between the load acting on the supported area by each pillar and their resulting reactive force. Unfortunately this and other evaluations do not consider, as a rule, the discontinuities structural control. The authors of this paper propose an approach to perform these calculations taking into account the effects of the rock mass structural control based on the Mohr-Coulomb and Barton & Bandis criteria. Interesting conclusions about such analyses were reached, since that the failures in these cases are predominantly planar.


One of the most important aspects pertaining to the stability of underground excavations in rock concerns the correct design of its structural elements. Of these one of the most important is the pillar, not only in certain mining methods, but in various works in rock excavations.

Therefore, it is important to consider the various types of pillars in rocks and the specific conditions and necessities that determine them, whether of geological nature or related to the excavations' intended use, so that the correct project is performed.

Regarding its use, the pillars' types are classified as:

  • Support Pillars,

  • Protection Pillars and

  • Control Pillars.

Support pillars in mining are those in which the main support of the overlying part not mined is constituted by a system of pillars, generally systematically or modally organized.

This content is only available via PDF.
You can access this article if you purchase or spend a download.