CLIENT: 

US Department of the Interior, Office of Surface Mining

Alpine Allegheny, Inc. provided project management services for the drilling and grouting of four abandoned mine shaft with an average dimension of 15’ long X 6’ wide, and averaged 160 vertical feet in depth.

The entire shaft had been abandoned between 50 and 90 years ago, and filled with organic or demolition debris that have a potential for subsiding.  The mines are also flooded because their working elevation is below the pool elevation of Lake Huron and since these were small roof and pillar mines, the pH of the mine pool was acidic.  

Water coming in contact with the demolition debris would cause it to break down into a mushy material, causing a sink hole.  Contractor drilled on an angle to intersect the shafts every 25-vertical feet then pumped them under pressure with fly-ash and Type II cement mix to seal any voids in the shaft.  After remediation, the sites were reclaimed to general use by the property owners. 

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Completed:  2016