TROVANTS OF THE LENA RIVER: HYPOTHESIS AND FORMATION MODEL

Unusual nodule formations have long been known in the steep banks of the Lena River and its tributaries. Their belonging to the category of Trovants (trovantogenesis) has been established. It is shown that trovants formation (trovantogenesis) is a process of specific transformation of cemented sands to varying degrees in platform and sub-platform environments. The hypothesis expressed by Romanian geologists about the pseudo-concretionary nature of the trovants has been confirmed. The aqua-dissipative model of their genesis is proposed. The variant of genetic сlassification of small geological bodies wherein trovants are classified as a consistent type is discussed.

Influence of Compaction on the Properties of Remolded Cemented Sands

The properties and behaviour of compacted cemented sands in Kuwait were examined by laboratory and model tests. Upon excavation the cementation bonds are destroyed and the material, locally known as gatch, is transformed into clayey sands with fines content (<0.075 mm) ranging from 20% to 40%. Testing included basic properties, compaction, permeability, direct shear and consolidation tests. Model tests were also carried out on a circular plate loaded on compacted soils to failure. The test soil was compacted to a relative compaction of 85%, 90%, 95% and 100%. The results indicate a significant decrease in the ultimate bearing capacity and the shear strength parameters c, ϕ, and an increase in the compressibility parameters Cc, Cs and the permeability as the relative compaction decreases from 100% to 85%. The rate of variation of the various soil parameters with relative compaction is examined.