Influence of fly ash gdsv on the liquefaction behavior of sandy soils

Industrialization and urbanization promote increasing consumer demand for energy and raw materials, producing a huge amount of industrial waste around the world annually. Fly ash is among the most common types of industrial waste. It is the byproduct of coal-fired thermal power plants and is usually stored outside the power plants, causing serious environmental concerns all around the world. The reuse of fly ash as soil-reinforcing material in different civil engineering applications is promising for sustainable development and may provide a viable solution to growing environmental problems associated with their disposal. Although there are various studies conducted to examine the effects of fly ash on the stabilization and basic engineering properties of cohesive soils, only a few relevant experimental studies exist on the effects of fly ash on the liquefaction characteristics of saturated clean sands. Further studies are needed in this area, so that fly ash can be used more effectively and reliably in civil engineering applications, especially in seismically active regions. In this study, Class-F fly ash was collected from the Seyitömer thermal power plant in Turkey. Loose and medium-dense triaxial specimens were prepared using sand-fly ash mixtures containing 0-40% of fly ash. The liquefaction characteristics of the specimens were examined through a series of 30 stress-controlled undrained dynamic triaxial tests. The tests were conducted at 1 Hz loading frequency and under initial effective confining stresses of 50 and 100 kPa. The detained analysis of experimental results showed that at a similar relative density, the liquefaction resistance of the sand-fly ash specimens decreased as the fly ash content increased up to about 20%, then slightly increased until the fly ash content reached 40%. Sand-only specimens showed greater liquefaction resistance than sand-fly ash specimens. The findings presented in this study are expected to contribute to the development of this research topic subject, providing useful insights into the advantages and disadvantages of the use of fly ash in geotechnical earthquake engineering applications.