Most candidates were able to: explain the reasons why the given types of soil
is difficult to use as a natural foundation.
However, majority were unable to use sketch to illustrate a method of
preventing subsoil moisture from penetrating through the walls and
floors of a building.
The expected response to question 1 is as given below:
(a) Explanation on soil difficulty
(i) Clay soil: It is subjected to seasonal movement which occurs when the soil dries and shrinks in the dry season and swells and heaves in the wet season. This expansion and contraction creates uneven settlement in the natural foundation.
- Loose soil: Trenches and pit may fail or collapse due to
lack of cohesion in the soil.
- Rocky soil: It is difficult to excavate and level to the required depth.
