Compression Characteristics of Resedimented Nile Silty Clay

摘要

The Nile sediments are characterized by its unique behavior where silt size particles exhibit significant plasticity. Cohesive Nile Sediments are collected and resedimented in two different forms of consolidometers. The paper presents a standardized process of resedimenting the silty clay in the laboratory. This research aims at characterizing the physical and mechanical properties of silty clay samples obtained from Mariouteya region in the Nile valley. The experimental program investigates the index properties of the sediments and grain size distribution using hydrometer and laser scattering particle analysis techniques. Results show how different classification approaches give different indications of sediment behavior. The compression behavior of the sediments is studied during resedimentation and by separate one-dimensional consolidation (oedometer) tests at pressures up to 3.2 MPa. The paper highlights and discusses the differences observed in compressibility during resedimentation and with conventional testing. The results show that the compressibility of Resedimented Nile Silty Clay (RNSC) at low pressures is within range measured from testing undisturbed samples from several locations along the Nile Valley and recorded in the literature. At high pressures the compression index decreases significantly and drops by 20% when pressure increases by an order of magnitude.