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.

Search our Collections & Repository

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Help
Clear All

Query Builder

Query box

Help
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Comparative study of blasting vibrations from Indiana surface coal mines

Filetype[PDF-2.00 MB]


  • English
    • Details You May Also Like

    Details:

    • Personal Author:
      Siskind, D. E.
    • Corporate Authors:
      United States. Bureau of Mines
    • Description:
      "The U.S. Bureau of Mines performed a comparative study of nine sites at eight surface coal mines to determine if the presence of near- surface underground abandoned workings resulted in the generation of adverse long-duration, low-frequency blast vibrations. Six of the nine sites had underlying workings, and two had thick layers of low- velocity unconsolidated surface material. Extended seismic arrays were used to identify the vibration characteristics within a few tens of feet of the blasts and also as modified by the propagating media at distances over 1 mile. Production blasts and specially fired single-charge blasts allowed the determination of natural ground frequency and the influence of initiation delay timing. Vibration amplitudes from the production blasts at all sites exceeded historical norms, particularly at the greater distances. This contrasts with the near-normal results from single-charge blasts. Apparently, between-hole time delays were insufficient to separate vibrations from adjacent charges for the low-frequency waves present. Single-charge tests showed that the propagating media produced low-frequency, ground-roll-type surface waves at nearly all sites. Large blasts at such sites could produce an unacceptable risk of vibration-induced cracks in nearby structures." - NIOSHTIC-2

      NIOSHTIC no. 10006966

    • Subjects:
    • Series:
      Report of investigations (United States. Bureau of Mines) ; 9226
    • Document Type:
      Report
    • Place as Subject:
      Indiana
    • Collection(s):
    • Main Document Checksum:
    • Download URL:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    You May Also Like

    Checkout today's featured content at stacks.cdc.gov