Percentile fragment size predictions for blasted rock and the fragmentation-energy fan

Ouchterlony, Finn and Sanchidrián Blanco, José Angel and Moser, Peter (2017). Percentile fragment size predictions for blasted rock and the fragmentation-energy fan. "Rock mechanics and rock engineering", v. 50 ; pp. 751-779. ISSN 0723-2632. https://doi.org/10.1007/s00603-016-1094-x.

Description

Title: Percentile fragment size predictions for blasted rock and the fragmentation-energy fan
Author/s:
  • Ouchterlony, Finn
  • Sanchidrián Blanco, José Angel
  • Moser, Peter
Item Type: Article
Título de Revista/Publicación: Rock mechanics and rock engineering
Date: April 2017
Volume: 50
Subjects:
Faculty: E.T.S.I. de Minas y Energía (UPM)
Department: Ingeniería Geológica y Minera
Creative Commons Licenses: Recognition - No derivative works - Non commercial

Full text

[img]
Preview
PDF - Requires a PDF viewer, such as GSview, Xpdf or Adobe Acrobat Reader
Download (1MB) | Preview

Abstract

It is shown that blast fragmentation data in the form of sets of percentile fragment sizes xP, as function of specific charge (powder factor, q) often form a set of straight lines in a log(xP) vs. log(q) diagram that tend to converge on a common focal point. This is clear for single-hole shots with normal specific charge values in specimens of virgin material and the phenomenon is called the fragmentation-energy fan. Field data from bench blasting with several holes in single or multiple rows in rock give data that scatter much more but examples show that the fragmentation data tend to form such fans. The fan behavior implies that the slopes of the straight size vs. specific charge lines in log-log space depend only on the percentile level in a given test set-up. It is shown that this property can be derived for size distribution functions of the form P[ln(x/xmax)/ln(xmax/x50)]. An example is the Swebrec function; for it to comply with the fragmentation-energy fan properties, the undulation parameter b must be constant. The existence of the fragmentation-energy fan contradicts two basic assumptions of the Kuz-Ram model; i) that the Rosin-Rammler function reproduces the sieving data well and ii) that the uniformity index n is a constant, independent of q. This favors formulating the prediction formulas instead in terms of the percentile fragment size xP for arbitrary P-values, parameters that by definition are independent of any size distribution, be it the Rosin-Rammler, Swebrec or other. A generalization of the fan behavior to include non-dimensional fragment sizes and an energy term with implicit size dependence seems possible to make.

More information

Item ID: 50717
DC Identifier: http://oa.upm.es/50717/
OAI Identifier: oai:oa.upm.es:50717
DOI: 10.1007/s00603-016-1094-x
Official URL: https://link.springer.com/article/10.1007%2Fs00603-016-1094-x
Deposited by: Memoria Investigacion
Deposited on: 11 May 2018 08:24
Last Modified: 30 Apr 2019 11:07
  • Logo InvestigaM (UPM)
  • Logo GEOUP4
  • Logo Open Access
  • Open Access
  • Logo Sherpa/Romeo
    Check whether the anglo-saxon journal in which you have published an article allows you to also publish it under open access.
  • Logo Dulcinea
    Check whether the spanish journal in which you have published an article allows you to also publish it under open access.
  • Logo de Recolecta
  • Logo del Observatorio I+D+i UPM
  • Logo de OpenCourseWare UPM