Lavra subterrânea de mármore com enchimento para  recuperação dos pilares remanescentes

Bernardo Maria Frazão Félix da Costa

Key information

Authors:

Bernardo Maria Frazão Félix da Costa (Bernardo Maria Frazão Félix da Costa)

Supervisors:

Gustavo André Paneiro (Gustavo Paneiro)

Published in

July 5, 2022

Abstract

Considering the importance of the natural stone in Portugal, it is important to explore new ways of doing it more efficiently and sustainably. At the Estremoz-Borba-Vila-Viçosa anticline, top quality marble is produced and exported worldwide. This work aims to contribute to the transition for underground exploitation of this resource through the room and pillar method From previous studies on this topic, this thesis studies the possibility of exploiting the remaining pillars, typical of this mining method, using cemented rockfill (CRF) produced using the waste rock of the quarry. In a laboratory component the strength and deformability characteristics of the CRF were studied considering two parameters of this material: the particle size distribution and the curing time. From the laboratory results, numerical simulations were performed to investigate the possibility of exploiting the remaining pillars of marble. Two models were developed in different zones of the quarry through the RS2 software based on the finite element method. It was concluded that with the use of this backfill it is possible to exploit the remaining pillars in specific zones of the underground quarry since some other zones are not stable enough to do so. In addition, this work also examines the environmental aspect because it applies fundamental principles of Circular Economy with the reuse of waste rock but also because it allows the exploitation of the remaining marble pillars with high economical value. Thus, the amount of waste rock left on the surface is lower and the amount of commercial marble is increased.