ExcAVATIONs

How soil is tested
A competent person must conduct visual and manual soil tests before
anyone enters an excavation. Visual and manual tests are a critical part
of determining the type of protective system that will be used.
Visual tests
Visual testing involves looking at the soil and the area around the
excavation site for signs of instability. The competent person might
do visual tests such as the following:
• Observe the soil as it is excavated. Soil that remains in large
clumps when excavated may be cohesive. Soil that breaks up
easily is granular.
• Examine the particle sizes of excavated soil to determine how
they hold together.
• Look for cracks or fissures in the faces of the excavation.
• Look for layers of different soil types and the angle of the layers
in the face of the excavation that may indicate instability.
• Look for water seeping from the sides of the excavation.
• Look for signs of previously disturbed soil from other
construction or excavation work.
• Consider vibration from construction activity or highway traffic
that may affect the stability of the excavation.
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