Geotechnical Investigation for Designing Underground Natural Stone Mines

Due to many reasons the underground excavation of natural stone becomes more and more acceptable all over the world. But even now, the basic problem in underground natural stone mines is the problem of room and pillar stability, relating to their width and height in stratified rock masses. In order to solve these problems an investigation was carried out, consisting of geological data collection, especially structural data, in situ and laboratory testing, application of analytical and numerical methods and measurement of rock deformation. The results of this investigation are presented in this paper, as well as the development of special rock strength criterion by comparing laboratory and in situ testing data, and its application in analytical and numerical models for designing underground spaces.