Shoring

Shoring is a general term used in construction to describe the process of supporting a structure in order to prevent collapse so that construction can proceed. The phrase can also be used as a noun to refer to the materials used in the process.

Buildings- It is used to support the beams and floors in a building while a column or wall is removed. In this situation vertical supports are used as a temporary replacement for the building columns or walls.

Trenches - During excavation, shoring systems provide safety for workers in a trench and speed excavation. In this case, shoring should not be confused with shielding. Shoring is designed to prevent collapse where shielding is only designed to protect workers when collapses occur. Concrete structures shoring, in this case also referred to as falsework, provides temporary support until the concrete becomes hard and achieves the desired strength to support loads.

Ships - It is used onboard when damage has been caused to a vessels integrity, and to hold leak-stopping devices in place to reduce or stop incoming water. Generally consists of timber 100 mm x 100 mm and used in conjunction with wedges, to further jam shoring in place, pad pieces to spread the load and dog's to secure it together. also used onboard is mechanical shoring as a quick, temporary solution, however it isn't favoured due to its inability to move with the vessel.

Shoring Techniques

Buildings

Raking Shore

Raking Shores consist of one or more timbers sloping between the face of the structure to be supported and the ground. The most effective support is given if the raker meets the wall at an angle of 60 to 70 degrees. A wall-plate is typically used to increase the area of support.

Foundations

Shoring is commonly used when installing the foundation of a building. A shoring system such as piles and lagging or shotcrete will support the surrounding loads until the underground levels of the building are constructed.

Trenches

Hydraulic Shoring

Hydraulic shoring is the use of hydraulic pistons that can be pumped outward until they press up against the trench walls. They are typically combined with steel plate or plywood, either being 1-1/8" thick plywood, or special heavy Finland Form (FINFORM) 7/8" thick.

Beam and Plate

Beam and Plate steel I-beams 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.

Soil Nailing

Soil nailing is a technique in which soil slopes, excavations or retaining walls are reinforced by the insertion of relatively slender elements - normally steel reinforcing bars. The bars are usually installed into a pre-drilled hole and then grouted into place or drilled and grouted simultaneously. They are usually installed untensioned at a slight downward inclination. A rigid or flexible facing (often sprayed concrete) or isolated soil nail heads may be used at the surface.

Continuous Flight Augering

Continuous Flight Augering (CFA) is a method used to create concrete piles to support soil so that excavation can take place nearby. A Continuous Flight Augering drill is used to excavate a hole and concrete is injected through a hollow shaft under pressure as the auger is extracted. This creates a continuous pile without ever leaving an open hole.

Ships

Square Shoring

This consists of a timber member jammed on a pad piece on either the deck or deck head depending on water levels in the compartment and a strong point, this is called the proud. then the is a horizontal timber cut to size to fit between this and what it is shoring up, eg a splinter box, bulkhead or door. Timber wedges are then used to tighten up the structure if necessary

Vertical Shoring This is to support a hatch or splint box on the deck, consisting of a vertical timber between the deck and deck head, with to wedges used opposing each other to tighten it. pad pieces are used to spread the load on weak structures.

Gallery

• V-shores.jpg

  Vertical or dead shore system, typically used in formwork.

• Fixing-tilt-slabs.jpg

  Single steel raking shore system specifically for tilt slab shoring.

• Angkor-dead-shores.jpg

  Angkor Wat complex, simple combination of timber raking and dead shores.

• Double-raking-shore.png

  Sketch of a timber double raking shore. Projected centre lines of floors and shores meet.

• Detail-raking-shore.png

  Carpentry detail of the joint at the top of a timber raking shore.

• Flying-shore.png

  Sketch of a timber single flying shore between adjacent buildings.

• Excavation-timbering.png

  Traditional trench shoring or Timbering.

• 

  Schematic sketch of a modern steel trench shore being lowered into a trench.

References

12px This article incorporates text from a publication now in the public domain: 

External links

• An illustrated glossary of the terms used in temporary types of construction work. Formwork, scaffolding etc.
• The Scaffolding, Shoring & Forming Institute (SSFI)
• Mabey Bridge & Shore, Inc.de:Grubenausbau