A in the foundation is the type of foundation that transfers the building load to the earth farther down from the surface than the shallow foundation not to the subsurface or various depths.
A stack or stack is a vertical structural element of a deep foundation, pushed or drilled deep into the ground at the building site.
There are many reasons that geotechnical engineers will recommend a deep foundation on a shallow foundation, such as for skyscrapers. Some common reasons are very large design loads, poor soils in shallow depths, or site constraints such as property lines. There are different terms used to describe different types of foundations in including the pile (which is analogous to the pole), the dock (which is analogous to the columns), the drilled axis, and the caissons. Piles are generally pushed to the ground in place; Other inner ponds are usually installed using excavation and drilling. Naming conventions may vary between engineering and enterprise disciplines. A deep foundation can be made of wood, steel, reinforced concrete or prestressed concrete.
Video Deep foundation
Foundation driven
The prefabricated stack is pushed to the ground using the stack driver. Driven piles constructed of wood, reinforced concrete, or steel. A pile of wood is made of high tree trunks. Concrete piles are available in rectangular, octagonal, and rounded shapes (like the Franki pile). They are reinforced with rebar and often prestressed pressed. The steel pile is a pile of pipe or some kind of jet piece (like a H-pile). Historically, piles of wood use splices to combine several segments from end to end when the required push depth is too long for one pile; today, a general connection with steel piles, although concrete piles can be connected in mechanical and other ways. Driving the pile, compared to the drilling shaft, is advantageous because the land moved by moving the pile compresses the surrounding soil, causing greater friction against the sides of the pile, thereby increasing their load-bearing capacity. Push-driven piles are also considered "tested" for load-bearing ability due to their installation method; thus the motto of the Pile Driving Contractors Association is "A Driven Pile... Is a Tested Pile!".
Pile foundation system
The foundations that depend on the stack are driven often have groups of piles connected by pile cap (a large concrete block that houses the embedded pile head) to distribute a load greater than one pile can be borne. The piles of stacks and isolated piles are usually connected to class blocks to bind the foundation elements together; lighter structural elements survive in class blocks, while heavier elements are directly attached to the pile.
Monopile foundation
monopile foundations use a single, generally large-diameter foundation element element to support all loads (weight, wind, etc.) of large upper surface structures.
A large number of monopile foundations have been used in recent years to build an offshore windstrip in shallow underwater seas. For example, the Horns Rev farm wind farm from 2002 in the North West Sea of ​​Denmark used 80 large monopils of 4 meters in diameter that sank to a depth of 25 meters to the seafloor, while Lynn and Inner Dowsing Wind Farm offshore UK online in 2008 with over 100 turbines , each mounted on a monopile base of 4.7 meters in depth of the ocean up to 18 meters of water.
The typical construction process for the underwater turbine beneath turbine foundation in the sand includes riding a large hollow steel pile, about 4 m in diameter with a wall thickness of about 50mm, about 25 m to the seafloor, through a layer of 0.5m from a larger rock. and gravel to minimize erosion around the pile. A "transitional section (complete with pre-installed features such as ship landing arrangements, cathodic protection, submarine cable channels, turbine tower flanges, etc.)" Attached to the now highly driven pile, sand and water removed from the center of the pile and replaced with concrete. An additional layer of larger stones, up to 0.5 m in diameter, is applied to the surface of the seafloor for long-term erosion protection.
Maps Deep foundation
Drill pile
Also called caissons , drilled axis , drill pole , Drill-in-drilled bore hole (CIDH pile) or pile Cast-in-Situ , drill holes drilled to the ground, then concrete (and often some kind of amplifier) ​​is placed into the borehole to form the pile. Rotary boring technique allows larger diameter stacks than other piling methods and allows the construction of stacks through solid or hard strata. The method of construction depends on the geology of the site; in particular, whether boring should be done in 'dry' soil conditions or through water-saturated strata. Casing is often used when drill hole sides tend to peel before concrete is poured.
For end-bearing piles, drilling continues until the drill hole has extended sufficient depth (socketing) into a fairly strong layer. Depending on the geology of the site, this can be a layer of rock, or hardpan, or other solid solid layers. Both the stack diameter and the pile depth are very specific for soil conditions, loading conditions, and project properties. The depth of the pile may vary substantially throughout the project if the bearing layer is uneven.
Drilled pillars can be tested using a variety of methods to verify the integrity of the stack during installation.
Under-reamed stack
The less well-known stack mechanically forms an enlarged base which has a diameter of 6 m. The shape is inverted cone and can only be formed in stable soil. The larger base diameter allows for a larger carrying capacity than a straight pivot stack.
This pile is suitable for expansive soils that often experience seasonal moisture variation, also filled with soil and soft or loose strata. They are used in normal soil conditions as well where economically profitable.
Augercast Stack
The augercast pile, often known as the advanced auger flight stack (CFA), is formed by drilling into the ground with a hollow continuous auger flight to the depth or required level of resistance. No casing is required. The cement grout mixture is then pumped into the auger rod. While the grout cement is pumped, the auger is slowly pulled, bringing the soil up along the flight. The cement semen shaft is formed to the ground. Reinforcement can be installed. The latest innovations besides rigorous quality controls allow the reinforcement of the cage to be placed up to the full length of the pile when needed. A typical reinforcement enclosure will consist of 4 to 8 bars from # 5 to # 8 bar typically 1/3 the length of the stack with an elongated round joint placed along the cage. Where there is a typical tension load to see a full length bar placed in the center of each pile.
Augercast piles cause minimal disruption, and are often used for environmentally sensitive noise and sites. Augercast piles are generally unsuitable for use in contaminated soil, due to the cost of expensive waste disposal. In such cases however the transfer pile can provide the cost efficiency of the augercast pile and minimal environmental impact. In soil containing barriers or rocks and boulders, the augercast pile is less suitable because of the rejection above the pile stack of design may be encountered. In some cases a drill motor that generates more torque and horsepower may reduce this event.
Pier and foundation of the class block
In the dock foundation drilled, the dock can be connected to a class block in which the structure sits, sometimes with heavy column loads directly on the dock. In some residential constructions, the docks are extended above ground level and timber beams that rely on the dock are used to support the structure. This type of foundation generates crawl space beneath buildings where wiring and channel work can be performed during construction or re-modeling.
Pile special
Micropiles
Micropiles, also called mini stacks, are often used for buffers. They are also used to create the foundations for various types of projects, including highway projects, bridges and transmission towers. They are particularly useful on sites with difficult or limited access, or with environmental sensitivity. Micropiles are made of steel with diameters of 60 to 200 mm. Installation of micropiles through top soil, sand and rock cover soil and into the rocks of soil can be achieved by using Air Rotary or Mud Rotary drilling, impact driving, jacking, vibrating or screwing machinery. Micropiles can also be used to construct nat columns around the axis of a standard Helical Pile system, which allows for use in higher load applications.
Tripod stack
The use of a tripod rig to install a pile is one of the more traditional ways to form piles. Although unit costs are generally higher than most other forms of stacking, it has several advantages that have ensured its continued use to this day. The tripod system is easy and inexpensive to carry to the site, making it ideal for work with a small number of piles.
Sheet piles
Sheet piling is a stack shape that is pushed using interlocked steel sheets to obtain a sustainable barrier in the ground. The main application of the pile of sheets is in maintaining the walls and cofferdams that are established to allow permanent work to proceed. Typically, vibrating hammers, t-cranes and crawling drilling are used to create piles of sheets.
Pile of warriors
The stack of soldiers, also known as the stack of kings or Berlin walls, is made of wide H-steel and spaced about 2 to 3 m apart and moved before excavation. As the excavation progresses, a horizontal wooden layer (left behind) is inserted behind the H-pile flange.
Horizontal soil pressure is concentrated on the pile of soldiers because of their relative stiffness compared to lagging. Ground movement and decline are minimized by maintaining lagging in contact with the soil.
Army piles are best suited in conditions where well-constructed walls will not produce a decline such as over-consolidated clay soil, soil above the water if they have some cohesion, and dry-free soil that can be effectively dried, like sand.
Unsuitable soils include soft clay and weak soil that allows large movements such as loose sand. It is also impossible to extend the wall outside the excavation base and frequent drying is required.
Screw stack
Screw stacks, also called helix hammers and screw foundations, have been used as foundations since the mid-19th century in screw-pile beacons. Screw piles are galvanized iron pipes with helical fins that are converted to ground by machine to the required depth. The screws distribute the load to the ground and are sized accordingly.
Suction Piles
The suction pile is used underwater to secure the floating platform. Tubular piles are pushed to the seafloor (or more often dropped a few meters to the soft seafloor) and then the pump sucks the water out at the top of the tubular, pulling the pile further down.
The proportion of the stack (diameter to high) depends on the type of soil. Sand is difficult to penetrate but provides good containment capacity, so that the height can be as high as half a diameter. The clay and mud are easily penetrated but provide poor containment capacity, so that the height can reach eight times the diameter. The open nature of gravel means that water will flow through the soil during installation, causing a 'piping' stream (where water boils over a weaker path through the soil). Therefore, the suction pile can not be used on the seafloor.
Adfreeze Piles
At high latitudes where the soil continues to freeze, the adfreeze pile is used as the primary structural foundation method.
Adfreeze piles get their strength from the frozen ground bonds around them to the surface of the pile.
The foundation of adfreeze pile is very sensitive in conditions that cause permafrost to melt. If a building is built incorrectly, it will heat the soil below that causes the foundation system failure.
Vibrate rock column
Vibrating rock columns are ground improvement techniques where rough aggregate columns ("stones") are placed on the ground with poor drainage or carrying capacity to repair the soil.
Hospital Stacks or Gallow Piles
Especially for marine structures, piles of hospitals are built to provide temporary support for marine structural components during repair work. For example, when moving a river pontoon, the eyebrows will stick to the hospital stack to support it. They are normal piles, usually with chains or hooks. Also known as the Gallow pile.
Stacked wall
This wall-retaining construction method uses a bored piling technique, usually CFA or rotary. They provide a special advantage in which the available workspace determines that the basement excavation surface becomes vertical. Both of these methods offer technically effective ways and offer a temporary efficient or temporary way to maintain bulk excavation even in water-filled strata. When used in permanent work, this wall can be designed to accommodate vertical loads in addition to moments and horizontal styles. The construction of both methods is the same as for the foundation that has a pole. The adjacent wall is made with a small gap between adjacent piles. The size of this space is determined by the strength of the soil.
Walls stacked secant
Secondary pile walls are constructed in such a way that space is left between the alternative piles of 'women' for the subsequent development of the 'men' pile. The construction of a 'male' pile involves boring through the concrete in the 'female' pile for the 'male' key of the pile between. The male pile is the place where the steel reinforcing enclosure is installed, although in some cases the female pile is also reinforced.
The secant stacking wall can be properly hard/hard, hard/medium (hard), or hard/soft, depending on the design requirements. Hard refers to the structural and firm or soft concrete is usually a mixture of weaker nat containing bentonite.
All types of walls can be constructed as free-standing cantilevers, or may be buffered if space and design permits are sub-structured. Where a party wall deal is possible, anchor anchors can be used as a back binder.
Slurry wall
The slurry wall is a barrier built underground using a mixture of bentonite and water to prevent groundwater flow. The ditch will collapse because the hydraulic pressure in the surrounding soil does not collapse because the slurry balances the hydraulic pressure.
Mass mixing/stabilization
This is essentially a variation of in situ reinforcements in the form of stacks (as mentioned above), larger blocks or volumes.
Cement, lime/quick lime, flyash, mud and/or other binders (sometimes called stabilizers) are mixed into the soil to increase the carrying capacity. The results are not as concrete, but should be seen as an increase in the carrying capacity of the original soil.
This technique is most often applied to clay or organic soil such as peat. Mixing can be done by pumping the binder into the soil while mixing it with a device usually attached to the excavator or by digging the mass, mixing it separately with the binder and refilling it in the desired area. This technique can also be used on mildly contaminated masses as a means of binding contaminants, as opposed to digging and transporting them to landfills or processing.
Classification of the stack with respect to material type
Wood
As the name implies, wooden piles are made of wood.
Historically, timber has become a locally available resource in many areas. Currently, wood piles are still more affordable than concrete or steel. Compared to other types of piles (steel or concrete), and depending on the source/type of wood, the wood pile may not be suitable for heavier loads.
The main consideration regarding wood piles is that they should be protected from decay above groundwater levels. The wood will last long under the surface of the groundwater. In order for wood to rot, it takes two elements: water and oxygen. Below groundwater levels, less dissolved oxygen even though there is plenty of water. Therefore, the wood tends to survive for a long time under groundwater. In 1648, the Royal Palace of Amsterdam was built on 13659 wooden piles that still survive today because they are below groundwater levels. The wood to be used on the surface of the water can be protected from decay and insects by various forms of wood preservation using pressure treatment (quartz copper alkali (ACQ), crimped copper arsenate (CCA), creosote, etc.).
Plugging wood piles is still fairly common and is the easiest of all materials that accumulate into splice. The normal method for grafting is to pilot the pile first, moving the steel tube (usually 60-100 cm long, with an internal diameter no smaller than the minimum toe diameter) halfway to the end of the leader's pile. The stack of followers is then just placed to the end of the tube and driving steadily. The steel tubes are just there to make sure that two pieces follow each other during driving. If lift capacity is required, the connection may incorporate bolts, coach screw, nails or the like to provide the required capacity.
Iron
Iron can be used to accumulate. This may be tenacious.
Steel
Pile piles are a kind of steel-driven pile foundation and are good candidates for bumps.
The pipe pile can be pushed either the open end or the closed end. When pushed open the end, the ground is allowed to enter the bottom of the pipe or tube. If an empty pipe is required, a water jet or auger can be used to remove the soil inside the next driving. The pile of closed end pipe is constructed by covering the bottom of the pile with a steel plate or cast steel shoe.
In some cases, the pile of pipe is filled with concrete to provide additional moment capacity or corrosion resistance. In the UK, this is generally not done to reduce costs. In these cases, corrosion protection is provided by allowing the thickness of the sacrificial steel or by using a steel with a higher level. If the pile of filled pipe is corroded, most of the stack carrying capacity will remain intact because of the concrete, while it will be lost in the empty pipe stack.
The structural capacity of the pile is mainly calculated based on the strength of steel and the strength of the concrete (if filled). Allowance is made for corrosion depending on site conditions and local building codes.
Stacks of steel pipes may be new steels specially manufactured for the reclamation steel recycling or casing industry previously used for other purposes such as oil and gas exploration.
H-Piles are structurally ground-driven beams for deep foundation applications. They can be easily cut or joined by welding or mechanical drive-fit splicers. If the pile is pushed to the ground with a low pH value, then there is a risk of corrosion, epoxy-tar coals or cathodic protection can be applied to slow or eliminate corrosion processes. It is common to allow a certain amount of corrosion in the design by simply measuring the cross-sectional area of ​​the steel pile. In this way, the corrosion process can be extended to 50 years.
Prestressed concrete stack
Concrete piles are usually made with steel reinforcement and prestress tendons to obtain the required tensile strength, for survival in handling and driving, and to provide adequate bending resistance.
Long stacks can be difficult to handle and transport. Pile joints can be used to combine two or more short stacks to form one long pile. Pile joints can be used with precast and prestressed concrete stacks.
Composite stack
A "composite pile" is a pile made of steel and concrete members tied together, end to end, to form a single pile. It is a combination of different materials or different shaped materials such as pipes and H-beams or steel and concrete.
Water accumulation s/ Ocean Stacking s
Wood (and other) buildup is used to support in structures raised above water, for docks, docks, jettys, bridges, oil platforms, and lighthouses. It should be specially treated to avoid corrosion.
See also
- Eurocode EN 1997
- The International Society for Micropiles
- Posting in soil construction is also called earthfast construction or posthole; historic method to build wooden structures.
- Stage house, also known as lake house; type of ancient and historic house built on a pole.
- Shallow foundation
- Pile bridge
Note
References
- Italiantrivelle Foundation Industry Deep Foundation's web portal Italiantrivelle is the number one source of information related to the Foundation Industry.
- Fleming, W. G. K. et al., 1985, Piling Engineering, Surrey University Press; Hunt, R. E., Analysis and Evaluation of Geotechnical Engineering, 1986, McGraw-Hill.
- Coduto, Donald P. Basic Design: Principles and Practice 2nd ed., Prentice-Hall Inc., 2001.
- NAVFAC DM 7.02 U.S. Earth Foundation and Structure Naval Facilities Engineering Command, 1986.
- Rajapakse, Ruwan., Pile Design and Construction Guide , 2003
- Tomlinson, P.J., Pile Design and Construction Practice , 1984
- Organic Soil Stabilization
- The sheet piling handbook, 2010
External links
- Yayasan Mendalam Foundation
- International Construction Equipment
- PDCA: Pile Driving Contractors Association
- ADSC: International Foundation Foundation Drilling Association
- The International Society for Micropiles
- Federation of Piling Specialists (UK)
- Procedure Installing a Bored Pile
Source of the article : Wikipedia
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