Floor heaving that is occurring at several underground facilities is a problem of major concern to the underground operators. These movements very likely occur as a consequence of one or more of the following possibilities: (1) removal of limestone in mining operations removes the confining pressure on the shale, thus allowing it to expand; (2) chemical reactions among various constituents in the shale result in crystal growth which results in an increase in volume of the shale and produces upward-directed stresses of large magnitude (crystal growth is accelerated by the presence of bacteria); (3) an increase in the moisture content of shale high in clay minerals of the montomrillonite group will result in large volume increases and could be a factor in floor heaving; and (4) the weight of overburden on the limestone pillars may exceed the load-bearing capacity of the shale, with the result that the incompetent shale moves outward from under the pillars. It is suggested that coordinated effort among all individual concerned with this problem would help in the finding of a solution.

Media Info

  • Pagination: p. 123-124

Subject/Index Terms

Filing Info

  • Accession Number: 00130644
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Apr 7 1976 12:00AM