Shoring

Last updated

Shoring is the process of temporarily supporting a building, vessel, structure, or trench with shores (props) when in danger of collapse or during repairs or alterations. Shoring comes from shore, a timber or metal prop. [1] Shoring may be vertical, angled, or horizontal.

Contents

Methods

Buildings

Single steel raking shore system specifically for tilt slab shoring. Fixing-tilt-slabs.jpg
Single steel raking shore system specifically for tilt slab shoring.

Raking shores

In this method, inclined members called rakers are used to give temporary lateral support to an unsafe wall. One or more timbers slope between the face of the structure to be supported and the ground. [2] 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. Commonly used shoring equipment includes post shores, shoring beams, and timber jacks.

Trenches

Schematic sketch of a modern steel trench shore being lowered into a trench. Trench-shoring.png
Schematic sketch of a modern steel trench shore being lowered into a trench.

During excavation, shoring systems speed up excavation and provide safety for workers since trenches can be prone to collapse. 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-structure and stone-building shoring, in these cases also referred to as falsework, provides temporary support until the concrete becomes hard and achieves the desired strength to support loads.

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.

Shoring in ships

Shoring is used on board when damage has been caused to a vessel's 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 dogs to hold it together. Also used on board is mechanical shoring as a quick, temporary solution, however it isn't favoured due to its inability to move with the vessel.

Proud

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 there is a horizontal timber cut to size to fit between this and what it is shoring up, e.g. 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 two wedges used opposing each other to tighten it. Pad pieces are used to spread the load on weak structures.

Shoring in air freight

Shoring is a term used in the process of air freight container and pallet (ULD) buildup, e.g. making sure that the cargo placed in containers and on pallets is packed securely and efficiently. Specifically, shoring is done to affix cargo to the ULD and adapt different form factors of cargo items to maximize the use of the available ULD volume. Typically, wooden beams and various forms of boards are used. Most often, shoring material is re-used but as the airfreight industry uses high-quality timber, shoring material often disappears and is a non-insignificant cost of cargo transport.

See also

Related Research Articles

<span class="mw-page-title-main">Suspension bridge</span> Type of bridge

A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical suspenders, have a long history in many mountainous parts of the world.

<span class="mw-page-title-main">Scaffolding</span> Temporary structure used to support a work crew and materials

Scaffolding, also called scaffold or staging, is a temporary structure used to support a work crew and materials to aid in the construction, maintenance and repair of buildings, bridges and all other human-made structures. Scaffolds are widely used on site to get access to heights and areas that would be otherwise hard to get to. Unsafe scaffolding has the potential to result in death or serious injury. Scaffolding is also used in adapted forms for formwork and shoring, grandstand seating, concert stages, access/viewing towers, exhibition stands, ski ramps, half pipes and art projects.

<span class="mw-page-title-main">Retaining wall</span> Artificial wall used for supporting soil between two different elevations

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. They are used to bound soils between two different elevations often in areas of inconveniently steep terrain in areas where the landscape needs to be shaped severely and engineered for more specific purposes like hillside farming or roadway overpasses. A retaining wall that retains soil on the backside and water on the frontside is called a seawall or a bulkhead.

This page is a list of construction topics.

<span class="mw-page-title-main">Unit load device</span> Pallet or container used to load luggage, freight, and mail on aircraft

A unit load device (ULD) is a container used to load luggage, freight, and mail on wide-body aircraft and specific narrow-body aircraft. It allows preloading of cargo, confidence the containerised load will fit in the aircraft and efficient planning of aircraft weight and balance and reduced labour and time in loading aircraft holds compared with 'bulk-loading' single items of cargo or luggage by hand. Each ULD has its own packing list or manifest so that its contents can be tracked. A loaded aircraft cargo pallet secured with a cargo net also forms a ULD, but its load must be gauged for size in addition to being weighed to ensure aircraft door and hold clearances.

In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons:

<span class="mw-page-title-main">Falsework</span>

Falsework consists of temporary structures used in construction to support a permanent structure until its construction is sufficiently advanced to support itself. For arches, this is specifically called centering. Falsework includes temporary support structures for formwork used to mold concrete in the construction of buildings, bridges, and elevated roadways.

<span class="mw-page-title-main">Concrete slab</span> Flat, horizontal concrete element of modern buildings

A concrete slab is a common structural element of modern buildings, consisting of a flat, horizontal surface made of cast concrete. Steel-reinforced slabs, typically between 100 and 500 mm thick, are most often used to construct floors and ceilings, while thinner mud slabs may be used for exterior paving (see below).

<span class="mw-page-title-main">Formwork</span> Molds for cast

Formwork is molds into which concrete or similar materials are either precast or cast-in-place. In the context of concrete construction, the falsework supports the shuttering molds. In specialty applications formwork may be permanently incorporated into the final structure, adding insulation or helping reinforce the finished structure.

<span class="mw-page-title-main">Girder bridge</span> Bridge built of girders placed on bridge abutments and foundation piers

A girder bridge is a bridge that uses girders as the means of supporting its deck. The two most common types of modern steel girder bridges are plate and box.

<span class="mw-page-title-main">Deep foundation</span> Type of foundation

A deep foundation is a type of foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. A pile or piling is a vertical structural element of a deep foundation, driven or drilled deep into the ground at the building site.

<span class="mw-page-title-main">Pallet racking</span> Material handling storage aid system designed to store materials on pallets

Pallet rack is a material handling storage aid system designed to store materials on pallets. Although there are many varieties of pallet racking, all types allow for the storage of palletized materials in horizontal rows with multiple levels. Forklift trucks are usually required to place the loaded pallets onto the racks for storage. Since the Second World War, pallet racks have become a ubiquitous element of most modern warehouses, manufacturing facilities, retail centers, and other storage and distribution facilities. All types of pallet racking increase storage density of the stored goods. Costs associated with the racking increases with increasing storage density.

<span class="mw-page-title-main">Trench shoring</span> Process for preventing the collapse of trenches

Trench shoring is the process of bracing the walls of a trench to prevent collapse and cave-ins. The phrase can also be used as a noun to refer to the materials used in the process.

A shipping container is a container with strength suitable to withstand shipment, storage, and handling. Shipping containers range from large reusable steel boxes used for intermodal shipments to the ubiquitous corrugated boxes. In the context of international shipping trade, "container" or "shipping container" is virtually synonymous with "intermodal freight container", a container designed to be moved from one mode of transport to another without unloading and reloading.

A jack post is a steel post used in the construction trades for temporary support of ceilings, walls and trenches (shoring). They are designed to be able to mechanically telescope to about twice their shortest length in order to span a wide variety of spaces. Most examples use removable pins for coarse adjustment and a jack screw for fine adjustments, but many variations exist.

<span class="mw-page-title-main">Demolition</span> Tearing-down of buildings and other structures

Demolition is the science and engineering in safely and efficiently tearing down of buildings and other artificial structures. Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for reuse purposes.

This glossary of structural engineering terms pertains specifically to structural engineering and its sub-disciplines. Please see glossary of engineering for a broad overview of the major concepts of engineering.

This page is a glossary of Prestressed concrete terms.

<span class="mw-page-title-main">Loddon Bridge disaster</span> 1972 English construction disaster

The Loddon Bridge disaster was a collapse of falsework during construction of a reinforced concrete deck on the Loddon Bridge of the A329(M) motorway in Berkshire, England, on 24 October 1972. It killed three people and injured ten others. It is thought that a design error led part of the falsework, transitioning between the deck and the supporting towers, to be understrength and it failed by buckling or twisting. The part-poured deck fell into the river below. The collapse was investigated by Her Majesty's Factory Inspectorate and the contractor, Marples Ridgway pleaded guilty to a breach of the construction regulations at a trial in Bracknell, being fined £150.

References

  1. "shore, n. 3." def, 1. Oxford English Dictionary Second Edition on CD-ROM (v. 4.0) © Oxford University Press 2009
  2. Chisholm, Hugh, ed. (1911). "Shoring"  . Encyclopædia Britannica . Vol. 24 (11th ed.). Cambridge University Press. pp. 1004–1007.