Page 8 - Trench and Excavation

Trench Jack- screw-type devices, which may be used as a cross-brace if manufactures
specifications, allow it and are on-site.
TSF- Tons per square foot.
Type A Soil- Cohesive soil with an unconfined compressive strength of 1.5 TSF or greater.

Type B Soil- Cohesive soil with an unconfined compressive strength less than 1.5 TSF but
greater than 0.5 TSF.

Type C Soil- Non-cohesive soil with an unconfined compressive strength less than 0.5 TSF.
Unconfined Compressive Strength- Load per unit area which will cause the soil to fail in
compression.
Underpinning- Temporary support for a foundation or other structure which lies under the
foundation or structure.
Uprights- Vertical members of a shoring system who distribute the compressive force generated
by the cross-braces to the trench walls.

Wale- A horizontal member of a shoring system which is parallel with the trench wall and is
between the upright and cross-brace. The wale distributes the compressive force of the cross-
brace to those uprights that do not have their own cross-brace.
Wellpoint- A method of removing water from the soil.

Wet Soil- Soil which contains more moisture than moist soil. Commonly, wet soil will slump when
vibrated, and granular soils that exhibit apparent cohesion when moist will flow when wet.

Trench & Excavation
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