Use of notched boreholes for fracture controlled blasting in the ornamental stone quarries

Tsoutrelis, CE; Gikas, N; Nomikos, P; Exadaktylos, G

dc.contributor.author	Tsoutrelis, CE	en
dc.contributor.author	Gikas, N	en
dc.contributor.author	Nomikos, P	en
dc.contributor.author	Exadaktylos, G	en
dc.date.accessioned	2014-03-01T01:46:15Z
dc.date.available	2014-03-01T01:46:15Z
dc.date.issued	1997	en
dc.identifier.issn	1385514X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/24879
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0031393341&partnerID=40&md5=af78e5295d4758bd91bf0b01bc04e3ef	en
dc.subject.other	quarry	en
dc.subject.other	blasting	en
dc.subject.other	fracture mechanics	en
dc.subject.other	quarrying	en
dc.title	Use of notched boreholes for fracture controlled blasting in the ornamental stone quarries	en
heal.type	journalArticle	en
heal.publicationDate	1997	en
heal.abstract	The ornamental stone industry is continuously seeking new cost effective methods to improve present day techniques of : (a) diamond wire cutting; (b) dense drilling followed by mechanical wedging or light blasting and (c) jet cutting, for extracting primary blocks from the quarry face and for splitting and squaring them to appropriate commercial sizes. Among the techniques proposed adn tested notching a borehole followed by wedging or decoupled blasting seems to be a commercially feasible technique provided that a suitable notching method becomes available. Notching can be used in soft non-abrasives stones such as marbles for splitting and squaring blocks and in hard and abrasive rocks (granites), where the diamond wire cutting technique can not be used effectively, for extraction from the bench face and for splitting and squaring. For marbles and many sandstones a detachable type notching tool fitted to a 7/8'' hexagon drill still can be used with a hand held or mechanically mounted rock drill in which the rotation mechanism has been removed. In granites and other abrasive rocks having fracture toughness values twice as big as those of marbles a two stage linear explosive (hybrid explosive) is proposed for extraction of the rock from the quarry face and for secondary treatment. Laboratory and field tests in three different types of marble blocks and in granite blocks in the laboratory proved the cost effectiveness of the proposed techniques, which are also environmentally friendly since they produce less dust and reduce noise duration in comparison to present day practice.	en
heal.journalName	Fragblast	en
dc.identifier.volume	1	en
dc.identifier.issue	4	en
dc.identifier.spage	445	en
dc.identifier.epage	463	en