Which of the following is not a construction process done to the soil?

Troweling is a process primarily associated with the finishing of concrete surfaces rather than a direct construction activity performed on soil. It involves smoothing and leveling the surface of set concrete to achieve a specific finish, such as a flat or textured surface. This activity focuses on the material of concrete rather than working directly with soil.

In contrast, excavation involves the removal of soil to create space for foundations or other construction elements, compacting is the process of increasing the density of soil to improve its load-bearing capacity, and grading is the process of leveling and sloping the surface of the soil to ensure proper drainage and stability. All these processes are fundamental steps in preparing a construction site and directly relate to soil manipulation. Thus, troweling stands out as the activity not associated with soil construction processes.