Gualcamayo Tunnel System

Client: Yamana Gold – Minas Argentinas S.A. | Location: San Juan Province, Jáchal District, Argentina | Year Completed: On-Going

Rizzo Associates Argentina S.A. and Rizzo Associates Chile S.A. (RIZZO) are carrying out geotechnical engineering, including a feasibility study and design for the Gualcamayo Crushing Chamber and Tunnel System, in one of the most important Argentinean mining projects to date. The Gualcamayo Project is being executed by Yamana Gold in the north of the San Juan Province, in the Jáchal District. The Project area encompasses the Andes foothills in the Province of San Juan, featuring San Juan formation outcrops composed of limestone and dolomites.

The initial Project included a primary crushing stage underneath the Open Pit to be operated in Cerro Diablo massif.

The next stage consists of a secondary crushing, for which purpose a conveyor belt will be used along a tunnel within the above-mentioned massif. In addition to the tunnels, the final Project will include a crushing chamber with a stepped descent and two Ore Passes.

The basis engineering project was designed by Hatch Mott MacDonald.

Yamana Gold has engaged RIZZO for two major assignments in Gualcamayo: the first contract consisted of directing geotechnical aspects for the construction of the chamber, tunnels and underground facilities. The second contract is for the geotechnical engineering design based on Hatch’s initial project (both being mostly under the direction of RIZZO Argentina).

This new component requires the design of a support structure capable of withstanding the crushing and transport process operations during the entire lifetime of the Project and providing appropriate support for the works to be carried out over the excavated area, taking into consideration the vibrations and absorption by the rock. The connection between the Open Pit and the Primary Crushing Chamber was initially proposed by RIZZO in the form of an Ore Pass (a vertical hole used simultaneously for the gravity transfer of ore to lower levels and as a storage silo). The system as a whole works as a plug-flow system, the operating conditions of which are governed by the primary crushing process demand.

Upon completion of the first stage of construction of the Ore Pass, and due to the Project’s operational requirements, Yamana decided to contract RIZZO to conduct the feasibility study and design of a second Ore Pass in the vicinity of the first (mostly under the responsibility of RIZZO Chile).

© 2014 Paul C. Rizzo Associates Inc.