Study on the production of artificial sand from non-hazardous dredged sludge in Hanoi City - Shear strength characteristics

Abstract

Based on the results of triaxial compression tests under consolidated drained conditions, this paper presents the shear strength characteristics of granular fill material (GFM) produced from dredged sediment in Hanoi City. The GFM material in the experiments was prepared from the same type of sediment (B), cement (X), and polymer (P) under the same conditions and following the same laboratory preparation procedure. The research results show that the shear strength of the GFM material increases with the cement content; at the same strain level, the stress and strain increase with the confining pressure; at low confining pressures, the sample exhibits dilatancy and increases in volume, which gradually decreases and stops completely with increasing confining pressure. At the initial stage of the shearing process, when the strain is still small, the stress ratio decreases sharply with increasing strain, however, immediately after that, the stress ratio increases proportionally with the strain until the sample fails. The GFM material has an internal friction angle ofφ’ = 35°÷38° which is directly proportional to the cement content. Although it is a granular material, the GFM material has a relatively high cohesion value of c’ =  (15÷38) kPa, indicating that it differs from natural sand.

Keywords: Artificial sand; granular fill material (GFM); shear strength characteristics.