What is the first state of consistency for fine-grained soils?

The first state of consistency for fine-grained soils is the liquid state. In this state, the soil is highly saturated with water and behaves like a viscous fluid. This means it can easily flow and cannot maintain shape, which is a characteristic of fine-grained soils like silts and clays when water content is high.

When fine-grained soils have enough moisture, they transition from a solid state through the plastic state, and eventually to the liquid state. In the liquid state, the soil particles are not in contact with each other as closely as they would be in the solid state, allowing for greater movement and flow. This understanding is essential for soil mechanics, geotechnical engineering, and when assessing the behavior of soils under varying moisture conditions.

The other states listed, such as solid, semisolid, and plastic, represent intermediary stages in the soil's consistency as it changes with varying water content, but none of these represent the starting point of that transition in fine-grained soils.