
Trench shoring is the process of bracing the walls of a
trench
A trench is a type of digging, excavation or depression in the ground that is generally deeper than it is wide (as opposed to a swale (landform), swale or a bar ditch), and narrow compared with its length (as opposed to a simple hole or trapping ...
to prevent collapse and
cave-ins. The phrase can also be used as a noun to refer to the materials used in the process.
Several methods can be used to shore up a trench. Hydraulic shoring is the use of
hydraulic pistons that can be pumped outward until they press up against the trench walls. This is typically combined with steel plate or a special heavy
plywood
Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...
called Finform. Another method is called beam and plate, in which
steel
Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...
I-beam
An I-beam is any of various structural members with an - (serif capital letter 'I') or H-shaped cross section (geometry), cross-section. Technical terms for similar items include H-beam, I-profile, universal column (UC), w-beam (for "wide flang ...
s are driven into the ground and steel plates are slid in amongst them. A similar method that uses wood planks is called soldier boarding. Hydraulics tend to be faster and easier; the other methods tend to be used for longer term applications or larger excavations.
Shoring should not be confused with shielding by means of
trench shield
Trench shields (also called trench boxes or trench sheets) are steel or aluminum structures used to avoid Cave-in (excavation), cave-ins and protect Public utility, utility workers while performing their duties within a trench. They are customa ...
s. Shoring is designed to prevent collapse, whilst shielding is only designed to protect workers should collapse occur. Most professionals agree that shoring is the safer approach of the two.
See also
*
Retaining wall
Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to ...
References
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Geotechnical shoring structures
Cuts (earthmoving)