##  [Case Study of the Rehabilitation of the Historical Coniagas No. 4 Shaft in Cobalt, Ontario](/resource/case-study-rehabilitation-historical-coniagas-no-4-shaft-cobalt-ontario) 

Organization

[Golder Associates Ltd.](/organization/golder-associates-ltd)

[Canadian Land Reclamation Association (CLRA)](/organization/canadian-land-reclamation-association-clra)

 

 

Project

[National CLRA Conference Papers](/project/national-clra-conference-papers)

 

Resource Type

[Report](/taxonomy/term/38)

 

 

Author(s)

Jonathon Taylor

Paul Palmer

Sean Legassie

Josée Noël

Jean Cayouette

Jean-François Doyon

 

 

Original Authors

Jonathon Taylor

Paul Palmer

Sean Legassie

Joseé Noël

Jean Cayouette

Jean-Francois Doyon

 

 

Resource Date:

2016

 

Page Length

13

 

 

Following the closure of the No. 4 Shaft, a grocer named Anthony Giachino purchased  
the building and constructed Giachino’s Grocery, enclosing the headframe with the  
store building in 1926 (Brown, 1999). Figure 1 shows the building in what is estimated  
to be the 1940’s. Giachino used the No. 4 Shaft and the cold air from the mine as a  
cold storage for produce and meats. Several businesses have since occupied the  
building including multiple restaurants (Figure 2 and Figure 3), and it is currently in use  
as a residential apartment and a publisher (Figure 4).

Experience on this rehabilitation has shown that cemented backfilling of mine openings  
to surface using a remotely constructed foam barricade is appropriate when  
infrastructure is present above the mine opening, or minimal disturbance of the  
surface/infrastructure is desired. The cost is comparable to constructing a monolithic  
cap above the mine opening, and concrete backfill should be considered as an  
alternative where possible. Application of the initial foam barricade is the greatest  
challenge, and the Coniagas No. 4 Shaft had favorable conditions of a vertical void with  
an obstruction at a reasonably shallow depth. Alternative methods of constructing a  
temporary barricade to build the foam plug, or incrementally building the foam plug from  
off of the rock walls, may be necessary depending on site and void geometry.