Intrinsic properties of Hellenic “Marls”

Abstract

Post-alpine deposits cover substantial areas of Hellas. The fine grained facies of these deposits, comprise a wide range of over consolidated materials of varying grading and mineralogy. On average, however, these deposits cover different depositional environments and may be classed as silty clays and clayey silts of low to intermediate plasticity containing calcite in their mineralogical suite. Such deposits have been collectively known to practising engineers as marls. A concerted effort to collect field and laboratory data and interpret the behaviour of these materials was recently launched in view of the involvement of the aforesaid mentioned deposits in a series of geotechnical problems. This thesis aspires to contribute to this knowledge and provide a framework on which the field performance of such materials may be interpreted. To that end, disturbed and high quality undisturbed samples from the geologically dissimilar areas of Korinthos, Preveza-Igoumenitsa road axis and Amalias- Goumeron were obtained and tested in order to ascertain their physical characteristics and mineralogical composition. Further, engineering properties which are independent of stress history, i.e. intrinsic, of the materials sampled, were determined. These were the residual strength as determined by ring shearing and the compressibility of reconstituted samples. The performance of the samples was assessed in terms of grain size distribution and mineralogy. The results show that any attempt to explain or predict intrinsic properties of Hellenic fine grained calcareous sediments without taking simultaneous account of gradation and mineralogy is incomplete and therefore inaccurate.