Geotechnical properties of the Ptolemais lignite

Kavvadas, M; Papadopoulos, B; Kalteziotis, N

dc.contributor.author	Kavvadas, M	en
dc.contributor.author	Papadopoulos, B	en
dc.contributor.author	Kalteziotis, N	en
dc.date.accessioned	2014-03-01T01:42:35Z
dc.date.available	2014-03-01T01:42:35Z
dc.date.issued	1994	en
dc.identifier.issn	09603182	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23875
dc.subject	anisotropy	en
dc.subject	bonding	en
dc.subject	cementation	en
dc.subject	Lignite	en
dc.subject	slope stability	en
dc.subject	yield surface	en
dc.subject.other	bonding	en
dc.subject.other	cementation	en
dc.subject.other	Cementation	en
dc.subject.other	Coal	en
dc.subject.other	geotechnical properties	en
dc.subject.other	lignite	en
dc.subject.other	Lignite	en
dc.subject.other	Mechanical Properties	en
dc.subject.other	Shear Strength	en
dc.subject.other	Water Content	en
dc.subject.other	Greece	en
dc.title	Geotechnical properties of the Ptolemais lignite	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/BF00429768	en
heal.identifier.secondary	http://dx.doi.org/10.1007/BF00429768	en
heal.publicationDate	1994	en
heal.abstract	The paper describes an investigation of the geotechnical properties of the Ptolemais lignite (brown coal) and shows that the soil mechanics principles used in the study of natural and cemented soils are applicable. The material has a high and variable void ratio incompatible with its preconsolidation pressure, which may be attributed to the existence of structure (chemical bonding). Bond strength and degradation have been studied and are found to be isotropic, while the stress-strain response in the prevield domain is intensely cross-anisotropic. The shear strength determined from triaxial CU and CD tests is variable but strongly dependent on the in situ moisture content. Tests on high quality intact specimens having a wide range of moisture contents (100-150%) verify a hypothesis that the magnitude of bond strength (expressed by the peak shear strength) is inversely proportional to the moisture content. A Hvorslev-type normalization process shows that the peak shear strength of the material can be estimated from the in situ moisture content with reasonable accuracy, thus facilitating preliminary stability calculations of production cuts in lignite mines. The properties of the Ptolemais lignite are compared with the properties of a lignite from another location in Greece (Megalopolis) and an Australian lignite (Morwell). It is shown that the shear strength characteristics of the lignite types studied are similar and strongly dependent on the in situ moisture content, which seems to be a measure of the magnitude of inter-particle bonding. © 1994 Chapman & Hall.	en
heal.publisher	Kluwer Academic Publishers	en
heal.journalName	Geotechnical and Geological Engineering	en
dc.identifier.doi	10.1007/BF00429768	en
dc.identifier.volume	12	en
dc.identifier.issue	2	en
dc.identifier.spage	87	en
dc.identifier.epage	112	en