Welcome to CDC stacks |
Stacks Logo
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.
Clear All Simple Search
Advanced Search
Hillseam geology and roof instability near outcrop in eastern Kentucky drift mines
Filetype[PDF-11.66 MB]

This document cannot be previewed automatically as it exceeds 5 MB
Please click the thumbnail image to view the document.
Hillseam geology and roof instability near outcrop in eastern Kentucky drift mines
  • Description:
    "This U.S. Bureau of Mines study was conducted in eastern Kentucky drift mines as part of an ongoing research program to characterize the outcrop barrier zone. "Hillseams" were identified as the dominant geologic cause of roof instability unique to the outcrop barrier zone, with many roof fall injuries and fatalities attributed to them. Hillseam is the eastern Kentucky miners term for weather- enlarged tension joints that occur in shallow mine overburden where surface slopes are steep. Hillseams are most conspicuous within 200 ft laterally of a coalbed outcrop and under 300 ft or less of overburden. Hillseams form by stress relief, and therefore tend to parallel topographic contours and ridges. They can intersect at various angles, especially under the nose of a ridge, and create massive blocks or wedges of roof prone to failure. Examples of hillseams are described in both outcrop and coal mine roof to establish their geologic character and contribution to roof failure." - NIOSHTIC-2

    NIOSHTIC no. 10007248

  • Document Type:
  • Place as Subject:
  • Main Document Checksum:
  • Supporting Files:
    No Additional Files
No Related Documents.
You May Also Like: