Liquefaction is a phenomenon where soil loses its strength and stiffness due to the shaking caused by seismic forces. During an earthquake, the ground shakes rapidly and causes the soil particles to lose their interlocking strength. As a result, the soil behaves like a liquid, and the buildings and other structures built on it can sink or tilt.

The soil type that is most likely to be subjected to liquefaction under seismic forces is loose saturated sands. This is because:

1. Porosity: Loose sands have a higher porosity than other soil types, which means they have more void spaces between the grains. This makes them more susceptible to liquefaction because there is more space for the water to flow through and destabilize the soil.

2. Density: Loose sands are less dense than other soil types, which means they are more easily compressed. This makes them more likely to lose their strength and stiffness during an earthquake.

3. Saturation: When soils are saturated with water, the water pressure increases and the soil particles become less interlocked. This makes the soil more susceptible to liquefaction. Loose sands are more likely to be saturated than other soil types because they have a higher porosity.

4. Shape: The shape of the sand particles can also contribute to liquefaction. Angular particles can interlock better than rounded particles, which makes the soil more resistant to liquefaction. Loose sands typically have rounded particles, which makes them more susceptible to liquefaction.

In summary, loose saturated sands are the most likely soil type to be subjected to liquefaction under seismic forces due to their high porosity, low density, high saturation, and rounded particle shape. It is important to consider the soil type and its susceptibility to liquefaction when designing structures in earthquake-prone areas.