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Shoring
Shoring is the process of temporarily supporting a building, vessel, structure, or trench with shores (Jack post, props) when in danger of collapse or during repairs or alterations. ''Shoring'' comes from ''shore'', a timber or metal prop. Shoring may be vertical, angled, or horizontal. Methods Buildings 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. 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 (engineering), 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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 customarily constructed with sidewalls of varying thicknesses held apart by steel or aluminum spreaders. Spreaders can be interchanged to match the width of the trench. The different materials and building designs lead to a variety of depth ratings: the depth of a trench that the shield can withstand a collapse without buckling. Depth ratings are determined by registered professional engineers. A shield should not be confused with a shore. While they may serve a similar function, trench shoring is a different physical application that holds up the walls of a trench to prevent collapse. In the US, use of a trench shield is governed by Occupational Safety and Health Administration, OSHA 29 CFR Part 1926.650-.652 Subpart P-Excavations. Externa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Box Crib
A box crib or cribbing is a temporary wooden structure used to support heavy objects during construction, Structural move, relocation, vehicle extrication and urban search and rescue. It is commonly used to secure overturned motor vehicles, and debris within collapsed buildings. Cribbing is often used in conjunction with other stabilization equipment, such as pneumatic or hydraulic shoring. Cribbing is also used in sub-surface mining as a roof support. Cribbing has largely been replaced by hydraulic jack, hydraulic shoring in modern mining applications. Some forms of cribbing can be used on movie sets and/or production sites for stabilizing dolly tracks, platforms, and various temporary structures when quick setup times are needed. Stability The stability of a crib is affected by a variety of factors: the material used (often a soft wood which gives audible warnings before failure), the number of contact points between the crib and the supported surface, the ratio of the footp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
House Raising
House raising (also called house lifting, house jacking, barn jacking, building jacking) is the process of separating a building from its foundation and temporarily raising it with hydraulic screw jacks. The process is the first step in structure relocation in which the building is moved to a different location. House raising may also be a part of a renovation to build a foundation under an existing house or make a house larger by adding a new floor level. Often employed in areas that are prone to flooding and storm damage, this process can be achieved through the use of either timber piles or helical piles. Once a house is raised and supported on cribbing, a new foundation can be constructed beneath it. After Hurricane Katrina and Hurricane Sandy large numbers of houses in parts of Louisiana, New York and New Jersey were raised to avoid future flooding. Jacking and shoring Shoring is the process of temporarily supporting a building, vessel, structure, or trench with s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jack Post
A jack post (screw jack, telepost, adjustable steel column) is a steel post used in the construction trades for temporary support of loads such as ceilings, walls, and formwork, concrete formwork, and as shoring in trenches. They are designed to be able to telescoping (mechanics), mechanically telescope to about twice the distance between their pre-drilled adjustment holes. Most examples use removable pins for coarse adjustment and a jack screw for fine adjustments, but many variations exist. Terminology Although jack posts are widely standardized, their terminology is not. "Jack post" is just one of many describing the same system: others include any assortment of "adjustable", "steel", "screw", "jack", and "shoring" with "post", "column", "jack", and "prop", depending on region, trade, and precise construction. The "jack" refers to examples with a jack screw to adjust the precise length of the post. They are also known by any number of proprietary names, notably "Acrow prop" in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wall-plate
A plate or wall plate is a horizontal, structural, load-bearing member in wooden building framing. Timber framing A plate in timber framing is "A piece of Timber upon which some considerable weight is framed...Hence Ground-Plate...Window-plate bsolete.." etc. Also called a wall plate, raising plate,Sturgis, Russell. ''Sturgis' illustrated dictionary of architecture and building: an unabridged reprint of the 1901-2 edition''. 1901. Reprint. Mineola, N.Y.: Dover, 1989. 159. Print. or top plate,Sherwood, Gerald E., and Robert C. Stroh. ''Wood-frame house construction''. Washington, D.C.: U.S. Dept. of Agriculture, Forest Service :, 1989. 54. Print. An exception to the use of the term plate for a large, load-bearing timber in a wall is the bressummer, a timber supporting a wall over a wall opening (see also: lintel). These are common in Australia. The terms sole plate or sill plate are used for the members at the bottom of a wall at the foundation but are most often just called a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foundation (engineering)
In engineering, a foundation is the element of a structural engineering, structure which connects it to the ground or more rarely, water (as with Floating building, floating structures), transferring force, loads from the structure to the ground. Foundations are generally considered either Shallow foundation, shallow or Deep foundation, deep. Foundation engineering is the application of soil mechanics and rock mechanics (geotechnical engineering) in the design of foundation elements of structures. Purpose Foundations provide the structure's stability from the ground: * To distribute the weight of the structure over a large area in order to avoid overloading the underlying soil (possibly causing unequal settlement). * To anchor the structure against natural forces including earthquakes, floods, droughts, frost heaves, tornadoes and wind. * To provide a level surface for construction. * To anchor the structure deeply into the ground, increasing its stability and preventing over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shotcrete
Shotcrete, gunite (), or sprayed concrete is concrete or mortar conveyed through a hose and pneumatically projected at high velocity onto a surface. This construction technique was invented by Carl Akeley and first used in 1907. The concrete is typically reinforced by conventional steel rods, steel mesh, or fibers. The concrete or mortar is formulated to be sticky and resist flowing when at rest to allow use on walls and ceilings, but exhibit sufficient shear thinning to be easily plumbable through hoses. Shotcrete is usually an all-inclusive term for both the wet-mix and dry-mix versions invented by Akeley. In swimming pool construction, however, ''shotcrete'' refers to wet mix and ''gunite'' to dry mix. In this context, these terms are not interchangeable. Shotcrete is placed and compacted/consolidated at the same time, due to the force with which it is ejected from the nozzle. It can be sprayed onto any type or shape of surface, including vertical or overhead areas. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falsework
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 concreteHardie G.M. (1995) Building Construction: Principles, Practices, and Materials. New Jersey: Prentice Hall. (Pg 116, paragraph 1) in the construction of buildings, bridges, and elevated roadways. The British Standards of practice for falsework, BS 5975:2008, defines falsework as "Any temporary structure used to support a permanent structure while it is not self-supporting." History Falsework has been employed in bridge and viaduct construction since ancient times. The Romans were renowned for its use, as at the Limyra Bridge in Turkey. Until the turn of the 20th century almost all falsework was constructed from timber. To compensate for timber shortages in different regions and to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Nailing
Soil nailing is a remedial construction measure to treat unstable natural soil slopes or unstable man-made (fill) slopes as a construction technique that allows the safe over-steepening of new or existing soil slopes. The technique involves the insertion of relatively slender reinforcing elements into the slope – often general purpose reinforcing bars (rebar) although proprietary solid or hollow-system bars are also available. Solid bars are usually installed into pre-drilled holes and then grouted into place using a separate grout line, whereas hollow bars may be drilled and grouted simultaneously by the use of a sacrificial drill bit and by pumping grout down the hollow bar as drilling progresses. Kinetic methods of firing relatively short bars into soil slopes have also been developed. Bars installed using drilling techniques are usually fully grouted and installed at a slight downward inclination with bars installed at regularly spaced points across the slope face. A rigid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dog (engineering)
In engineering, a dog is a tool or part of a tool, such as a pawl, that prevents or imparts movement through physical engagement. It may hold another object in place by blocking it, clamping it, or otherwise obstructing its movement. Or it may couple various parts together so that they move in unison – the primary example of this being a flexible drive to mate two shafts in order to transmit torque. Some devices use dog clutches to lock together two spinning components. In a manual transmission, the dog clutches, or "dogs" lock the selected gear to the shaft it rotates on. Unless the dog is engaged, the gear will simply freewheel on the shaft. This word usage is a metaphor derived from the idea of a dog (animal) biting and holding on, the "dog" name derived from the basic idea of how a dog jaw locks on, by the movement of the jaw, or by the presence of many teeth. In engineering the "dog" device has some special engineering work when making it – it is not a simple part to make ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
