Abstract: The amount of fly ash from domestic waste incineration is increasing year by year, with the majority being disposed of in landfills. However, the research on the soil mechanical characteristics of fly ash was relatively few, which was not conducive to guiding the landfill operation of fly ash. The geotechnical properties of stabilized incineration fly ash from a landfill in south China were tested, and were compared with the results of previous studies. The results indicated that the original fly ash from the municipal solid waste incineration could be classified as well-graded fine soil. After being stabilized and solidified by chemicals, lime, and cement, the particle size gradually increased and transformed into poorly graded fine sand, coarse sand, or even gravel. The geotechnical properties of fly ash in different landfills showed significant variation. The compression coefficient αv1-2 of fly ash from different landfills ranged from 0.26 to 2.96 MPa-1. The compressibility grade was medium to high. The cohesion force was 8.00 to 19.47 kPa, the friction angle was 32.50~36.30, and the unit weight was 11.0 to16.3 kN/m3.

Key words: stabilized incineration fly ash, geotechnical properties, compression coefficient, cohesive force, friction angle