DBPapers
DOI: 10.5593/sgem2012/s03.v1005

ANALYSIS OF THE CAUSES LEADING TO OVERPROFILES OCCURRENCE IN DEVELOPMENT OF THE LIVEZENI SECTOR HEAD RACE – DUMITRA AHE JIU

M. TODERAS
Wednesday 1 August 2012 by Libadmin2012

References: 12th International Multidisciplinary Scientific GeoConference, www.sgem.org, SGEM2012 Conference Proceedings/ ISSN 1314-2704, June 17-23, 2012, Vol. 1, 441 - 448 pp

ABSTRACT

A thorough analysis of the geological structure crossed-out by the head race highlights a
complex structure materialized by the presence of different types of rocks within the
Drăgşani series, Lainici – Păiuş, Rafaila series or the granitic complex of Şuşiţa. The
area being strongly affected by tectonics, led to the emergence of extensive bidding or
microfolds, to the presence of numerous normal and reverse faults that have divided the
area into blocks, the fault planes of rocks being strongly molded. All these phenomena
have led to a high degree of fracturing of rocks. In terms of geotechnical coefficients,
and quality indexes RMR and Q, rocks are grouped into 5 categories. Rocks can be
classified in terms of frequency of cracks (min. 1 - 2 cracks/ml) no later than rocks with
average degree of cracking, specific to class I; the other types of rocks must be placed in
highly fractured rocks (more than 3 cracks/m) or crushed rock. The high frequency of
cracks, the presence of highly stratified, schistuos rocks, has direct implications on both
the degree of workings stability and the process of their displacement. In order to
identify the causes that led to overprofiles occurrence, the employed blasting
monographs were analyzed, in terms of the type of explosive, means of initiation, the
number of mine openings and their location, the amount of explosive on the front of
attack on different types of rocks.

Keywords: geotechnical indices, cracks, deterioration, schistuosity, stability, dynamic
wave, mechanism of disruption, explosive, overprofile, blasting holes.