Lesson 3/Learning Event 1
Ground Water and Bedrock. All structures must be constructed at such an elevation that they will not
be adversely affected by the ground water table. The grade line must be raised or the ground water table
must be lowered when a structure may be adversely affected by capillary rise or by the ground water
table itself. Bedrock within the depth of excavation tremendously increases the time and equipment
requirements for excavation. If the amount is very extensive, it may be cause for a change in the grade
or even the site location.
Developing a Soils Profile. The soil profile is a graphical representation of a vertical cross-section of
the soil layers from the surface of the earth downward. A description of the development of the soil
profile will appear later in this lesson.