Role of Helical Anchors in Challenging Soil Conditions

Role of Helical Anchors in Challenging Soil Conditions

Case studies showcasing successful repair projects using various techniques.

Overview of challenging soil conditions and their impact on foundation stability.


Soil conditions play a crucial role in determining the stability and integrity of any foundation. Tilt meters track structural changes for effective home foundation repair foundation wall repair service ventilation. Challenging soil conditions refer to those that are not ideal for construction, including but not limited to expansive soils, soft clays, loose sands, and soils with high water content. These conditions can significantly impact the performance and longevity of foundations, necessitating the use of specialized solutions such as helical anchors.

Expansive soils, which swell when they absorb water and shrink when they dry, can exert significant pressure on foundations, leading to cracks and structural damage. Soft clays, on the other hand, offer minimal bearing capacity, making it difficult to support heavy loads without substantial settlement. Loose sands are prone to liquefaction during seismic events, which can cause foundations to lose stability. High water content soils, often found in marshy or flood-prone areas, can lead to buoyancy issues and undermine the foundation.

The impact of these challenging soil conditions on foundation stability is profound. Traditional foundation systems may not provide the required support, leading to increased costs for excavation, soil replacement, or additional reinforcement. Moreover, the risk of differential settlement-where different parts of the structure settle at different rates-can compromise the structural integrity and safety of the building.

Helical anchors emerge as a viable solution in such scenarios. These anchors consist of helical plates attached to a central shaft, which are screwed into the ground to engage with stronger soil layers beneath the problematic surface soils. By transferring the load to these deeper, more stable strata, helical anchors help mitigate the adverse effects of challenging soil conditions. They offer several advantages, including minimal ground disturbance, faster installation times, and the ability to be installed in tight spaces where traditional methods may be impractical.

In conclusion, understanding and addressing challenging soil conditions is vital for ensuring foundation stability. Helical anchors provide an effective and efficient means to overcome the difficulties posed by such soils, thereby enhancing the safety and durability of structures in otherwise problematic environments.

Explanation of how helical anchors work and their application in foundation repair.


Helical anchors, also known as helical piers or screw piles, are innovative solutions used in foundation repair, especially in challenging soil conditions. These devices consist of a central steel shaft with one or more helical-shaped plates attached. The operation of helical anchors is both simple and effective: they are screwed into the ground using a specialized drill rig. As the anchor is turned, the helices displace the soil, allowing the anchor to penetrate deeper until it reaches a stable soil stratum or bedrock.

The primary role of helical anchors in foundation repair is to provide additional support and stability to a structure's foundation. They are particularly useful in areas where the soil is unstable, such as expansive clays, loose sands, or areas affected by erosion. By transferring the load of the structure to deeper, more stable soil layers, helical anchors help prevent further settling or shifting of the foundation.

One of the key advantages of helical anchors is their minimal invasiveness compared to traditional foundation repair methods. They require less excavation, which means less disruption to the surrounding area and a quicker installation process. This is particularly beneficial in urban environments where space is limited, and traditional methods might not be feasible.

Helical anchors are also versatile in their application. They can be used for a variety of structures, including residential homes, commercial buildings, and even infrastructure like bridges and highways. In cases of foundation repair, they can be installed under existing foundations without the need for extensive demolition or reconstruction.

In summary, helical anchors play a crucial role in foundation repair, especially in challenging soil conditions. Their ability to provide stable support with minimal disruption makes them an ideal choice for a wide range of applications. As technology and materials continue to advance, the use of helical anchors is likely to become even more prevalent in the field of structural engineering.

Benefits of using helical anchors in residential foundation repair projects.


Certainly! Here's a human-like essay on the benefits of using helical anchors in residential foundation repair projects, focusing on their role in challenging soil conditions:

When it comes to residential foundation repair, especially in areas with challenging soil conditions, helical anchors have emerged as a game-changer. These ingenious devices, also known as helical piers or screw piles, offer a multitude of benefits that make them an ideal choice for stabilizing and lifting foundations in difficult terrains.

First and foremost, helical anchors are exceptionally effective in dealing with problematic soils. Whether it's expansive clay, loose sand, or areas prone to soil erosion, these anchors can be installed with minimal disturbance to the surrounding environment. Their helical design allows them to penetrate deep into the ground, reaching stable soil layers or bedrock, thereby providing a solid foundation for the structure above.

One of the key advantages of helical anchors is their versatility. They can be used in a variety of soil conditions and are particularly useful in areas where traditional foundation repair methods, like concrete piers, might not be feasible. This versatility makes them a go-to solution for residential foundation repair projects, as they can adapt to the unique challenges posed by different soil types.

Moreover, helical anchors are known for their efficiency. The installation process is relatively quick compared to other methods, which means less downtime for homeowners. This is particularly beneficial in residential settings where minimizing disruption is a priority. The speed of installation also reduces the overall cost of the repair project, making it a cost-effective solution for many homeowners.

Another significant benefit is the longevity and durability of helical anchors. Once installed, they are designed to withstand the test of time and various environmental conditions. This durability ensures that the foundation remains stable and secure for years to come, providing peace of mind to homeowners.

In addition to their practical benefits, helical anchors are also environmentally friendly. Their installation causes minimal disruption to the surrounding area, preserving the natural landscape and reducing the carbon footprint of the repair process. This eco-conscious approach is increasingly important in today's world, where sustainable practices are becoming a priority.

In conclusion, the use of helical anchors in residential foundation repair projects, particularly in challenging soil conditions, offers numerous benefits. From their effectiveness in various soil types and quick installation process to their durability and environmental friendliness, helical anchors prove to be a smart and sustainable choice for ensuring the stability and longevity of residential foundations.

Case studies showcasing successful foundation repairs using helical anchors in difficult soil conditions.


Helical anchors have emerged as a game-changer in the world of foundation repair, particularly in addressing the unique challenges posed by difficult soil conditions. Their innovative design and versatility have been showcased in numerous case studies, demonstrating their efficacy in stabilizing structures and ensuring long-term durability. This essay delves into the role of helical anchors in challenging soil conditions, highlighting successful case studies that underscore their effectiveness.

One notable case study involves a historic building located in a region with expansive clay soils. These soils are notorious for their tendency to swell and shrink with moisture changes, leading to significant foundation movement and structural damage. Traditional repair methods often proved insufficient in such conditions, but the introduction of helical anchors offered a promising solution. By installing helical anchors deep into the stable soil layers beneath the expansive clay, engineers were able to effectively stabilize the foundation and mitigate the effects of soil movement. The building, once at risk of severe damage, now stands as a testament to the power of helical anchor technology.

Another compelling case study comes from a coastal area prone to erosion and shifting sands. A luxury resort, facing imminent threats to its structural integrity due to the unstable soil conditions, turned to helical anchors as a last resort. The anchors were strategically placed to distribute the load more evenly and anchor the foundation securely into the deeper, more stable soil layers. This innovative approach not only saved the resort from potential collapse but also showcased the adaptability of helical anchors in extreme environmental conditions. The success of this project has since inspired similar applications in other coastal developments facing similar challenges.

In an urban setting, a high-rise building constructed on soft, compressible soils presented a unique set of challenges. The weight of the structure caused significant settlement, leading to cracks and uneven settling. Traditional methods of underpinning were deemed too invasive and costly. Helical anchors, however, offered a less disruptive and more cost-effective solution. By installing the anchors at specific points around the perimeter of the building, engineers were able to halt the settlement and redistribute the load, ensuring the structure's stability. This case study highlights the precision and efficiency with which helical anchors can be employed in densely populated areas where conventional methods may not be feasible.

These case studies, among others, vividly illustrate the critical role of helical anchors in addressing the complexities of challenging soil conditions. Their ability to provide stable support in diverse and difficult environments makes them an invaluable tool in the arsenal of foundation repair professionals. As we continue to face the impacts of climate change and urban development, the importance of innovative solutions like helical anchors cannot be overstated. They not only offer a reliable means of stabilizing existing structures but also pave the way for safer and more sustainable construction practices in the future.

Comparison of helical anchors with traditional foundation repair methods.


When it comes to foundation repair, especially in challenging soil conditions, helical anchors have emerged as a notable alternative to traditional methods. Understanding the differences and benefits of helical anchors compared to conventional techniques is crucial for both homeowners and construction professionals.

Traditional foundation repair methods often involve techniques such as underpinning, where additional support is added beneath the existing foundation. This can be done through methods like concrete piers or steel push piers. While these methods have been used for decades and have proven effective, they do come with certain limitations, particularly in areas with problematic soils.

One of the main challenges with traditional methods is the invasive nature of the repair process. Underpinning, for example, requires excavation around the foundation, which can be both time-consuming and disruptive. In urban areas or locations with limited space, this can pose significant logistical issues. Additionally, the weight and size of the materials used in traditional methods can exacerbate soil settlement issues, leading to a vicious cycle of repairs.

Helical anchors, on the other hand, offer a less invasive and more versatile solution. These anchors are screw-like devices that are installed into the ground to provide additional support to the foundation. The installation process for helical anchors is minimally invasive, requiring only small holes to be drilled into the ground. This means less disruption to the surrounding area and a quicker installation time compared to traditional methods.

Moreover, helical anchors are highly adaptable to different soil conditions. They can be adjusted in length and depth to reach stable soil layers, even in areas with expansive or unstable soils. This makes them particularly effective in challenging soil conditions where traditional methods might struggle. The ability to customize the installation to suit specific soil characteristics ensures a more reliable and long-lasting repair.

Another advantage of helical anchors is their load-bearing capacity. These anchors can support significant weight, making them suitable for a variety of foundation types and structural loads. This versatility means that helical anchors can be used in both residential and commercial settings, providing a consistent and effective solution across different applications.

In conclusion, while traditional foundation repair methods have their place, helical anchors offer a modern and efficient alternative, especially in challenging soil conditions. Their minimally invasive installation process, adaptability to different soil types, and high load-bearing capacity make them a valuable tool in the arsenal of foundation repair techniques. As soil conditions continue to present challenges for construction projects, the role of helical anchors is likely to become increasingly important in ensuring stable and durable foundations.

Factors to consider when choosing helical anchors for residential foundation repair.


When choosing helical anchors for residential foundation repair, especially in challenging soil conditions, several critical factors must be taken into account to ensure the effectiveness and longevity of the repair.

First, the type of soil is paramount. Different soils-such as clay, sand, or silt-have varying load-bearing capacities and can affect how well the helical anchors will grip and stabilize the foundation. Understanding the soil composition helps in selecting the appropriate size, length, and pitch of the helical plates.

Second, the depth and angle of installation are crucial. The depth at which the anchors are installed must be sufficient to reach stable soil layers, ensuring the anchors can effectively transfer the load from the foundation to the soil. The angle of installation also plays a role in maximizing the contact area between the anchor and the soil.

Third, the load requirements of the foundation must be accurately assessed. This involves calculating the weight of the structure and any additional loads it may bear, such as from furniture or occupants. The chosen helical anchors must be capable of supporting these loads without failure.

Fourth, the environmental conditions should be considered. Factors such as moisture levels, freeze-thaw cycles, and potential for soil erosion can impact the performance of helical anchors over time. Using materials that are resistant to corrosion and degradation in these conditions is essential.

Lastly, the expertise of the installation team is vital. Proper installation techniques are necessary to ensure the helical anchors function as intended. This includes precise drilling, correct torque application, and thorough inspection post-installation.

In summary, selecting helical anchors for residential foundation repair in challenging soil conditions requires a comprehensive assessment of soil type, installation depth and angle, load requirements, environmental conditions, and the skill of the installation team. By carefully considering these factors, homeowners can achieve a stable and durable foundation repair.



Redirect to:

  • Structural integrity and failure

 

Boston's Big Dig presented geotechnical challenges in an urban environment.
Precast concrete retaining wall
A typical cross-section of a slope used in two-dimensional analyzes.

Geotechnical engineering, also known as geotechnics, is the branch of civil engineering concerned with the engineering behavior of earth materials. It uses the principles of soil mechanics and rock mechanics to solve its engineering problems. It also relies on knowledge of geology, hydrology, geophysics, and other related sciences.

Geotechnical engineering has applications in military engineering, mining engineering, petroleum engineering, coastal engineering, and offshore construction. The fields of geotechnical engineering and engineering geology have overlapping knowledge areas. However, while geotechnical engineering is a specialty of civil engineering, engineering geology is a specialty of geology.

History

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Humans have historically used soil as a material for flood control, irrigation purposes, burial sites, building foundations, and construction materials for buildings. Dykes, dams, and canals dating back to at least 2000 BCE—found in parts of ancient Egypt, ancient Mesopotamia, the Fertile Crescent, and the early settlements of Mohenjo Daro and Harappa in the Indus valley—provide evidence for early activities linked to irrigation and flood control. As cities expanded, structures were erected and supported by formalized foundations. The ancient Greeks notably constructed pad footings and strip-and-raft foundations. Until the 18th century, however, no theoretical basis for soil design had been developed, and the discipline was more of an art than a science, relying on experience.[1]

Several foundation-related engineering problems, such as the Leaning Tower of Pisa, prompted scientists to begin taking a more scientific-based approach to examining the subsurface. The earliest advances occurred in the development of earth pressure theories for the construction of retaining walls. Henri Gautier, a French royal engineer, recognized the "natural slope" of different soils in 1717, an idea later known as the soil's angle of repose. Around the same time, a rudimentary soil classification system was also developed based on a material's unit weight, which is no longer considered a good indication of soil type.[1][2]

The application of the principles of mechanics to soils was documented as early as 1773 when Charles Coulomb, a physicist and engineer, developed improved methods to determine the earth pressures against military ramparts. Coulomb observed that, at failure, a distinct slip plane would form behind a sliding retaining wall and suggested that the maximum shear stress on the slip plane, for design purposes, was the sum of the soil cohesion, , and friction , where is the normal stress on the slip plane and is the friction angle of the soil. By combining Coulomb's theory with Christian Otto Mohr's 2D stress state, the theory became known as Mohr-Coulomb theory. Although it is now recognized that precise determination of cohesion is impossible because is not a fundamental soil property, the Mohr-Coulomb theory is still used in practice today.[3]

In the 19th century, Henry Darcy developed what is now known as Darcy's Law, describing the flow of fluids in a porous media. Joseph Boussinesq, a mathematician and physicist, developed theories of stress distribution in elastic solids that proved useful for estimating stresses at depth in the ground. William Rankine, an engineer and physicist, developed an alternative to Coulomb's earth pressure theory. Albert Atterberg developed the clay consistency indices that are still used today for soil classification.[1][2] In 1885, Osborne Reynolds recognized that shearing causes volumetric dilation of dense materials and contraction of loose granular materials.

Modern geotechnical engineering is said to have begun in 1925 with the publication of Erdbaumechanik by Karl von Terzaghi, a mechanical engineer and geologist. Considered by many to be the father of modern soil mechanics and geotechnical engineering, Terzaghi developed the principle of effective stress, and demonstrated that the shear strength of soil is controlled by effective stress.[4] Terzaghi also developed the framework for theories of bearing capacity of foundations, and the theory for prediction of the rate of settlement of clay layers due to consolidation.[1][3][5] Afterwards, Maurice Biot fully developed the three-dimensional soil consolidation theory, extending the one-dimensional model previously developed by Terzaghi to more general hypotheses and introducing the set of basic equations of Poroelasticity.

In his 1948 book, Donald Taylor recognized that the interlocking and dilation of densely packed particles contributed to the peak strength of the soil. Roscoe, Schofield, and Wroth, with the publication of On the Yielding of Soils in 1958, established the interrelationships between the volume change behavior (dilation, contraction, and consolidation) and shearing behavior with the theory of plasticity using critical state soil mechanics. Critical state soil mechanics is the basis for many contemporary advanced constitutive models describing the behavior of soil.[6]

In 1960, Alec Skempton carried out an extensive review of the available formulations and experimental data in the literature about the effective stress validity in soil, concrete, and rock in order to reject some of these expressions, as well as clarify what expressions were appropriate according to several working hypotheses, such as stress-strain or strength behavior, saturated or non-saturated media, and rock, concrete or soil behavior.

Roles

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Geotechnical investigation

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Main article: Geotechnical investigation

Geotechnical engineers investigate and determine the properties of subsurface conditions and materials. They also design corresponding earthworks and retaining structures, tunnels, and structure foundations, and may supervise and evaluate sites, which may further involve site monitoring as well as the risk assessment and mitigation of natural hazards.[7][8]

Geotechnical engineers and engineering geologists perform geotechnical investigations to obtain information on the physical properties of soil and rock underlying and adjacent to a site to design earthworks and foundations for proposed structures and for the repair of distress to earthworks and structures caused by subsurface conditions. Geotechnical investigations involve surface and subsurface exploration of a site, often including subsurface sampling and laboratory testing of retrieved soil samples. Sometimes, geophysical methods are also used to obtain data, which include measurement of seismic waves (pressure, shear, and Rayleigh waves), surface-wave methods and downhole methods, and electromagnetic surveys (magnetometer, resistivity, and ground-penetrating radar). Electrical tomography can be used to survey soil and rock properties and existing underground infrastructure in construction projects.[9]

Surface exploration can include on-foot surveys, geologic mapping, geophysical methods, and photogrammetry. Geologic mapping and interpretation of geomorphology are typically completed in consultation with a geologist or engineering geologist. Subsurface exploration usually involves in-situ testing (for example, the standard penetration test and cone penetration test). The digging of test pits and trenching (particularly for locating faults and slide planes) may also be used to learn about soil conditions at depth. Large-diameter borings are rarely used due to safety concerns and expense. Still, they are sometimes used to allow a geologist or engineer to be lowered into the borehole for direct visual and manual examination of the soil and rock stratigraphy.

Various soil samplers exist to meet the needs of different engineering projects. The standard penetration test, which uses a thick-walled split spoon sampler, is the most common way to collect disturbed samples. Piston samplers, employing a thin-walled tube, are most commonly used to collect less disturbed samples. More advanced methods, such as the Sherbrooke block sampler, are superior but expensive. Coring frozen ground provides high-quality undisturbed samples from ground conditions, such as fill, sand, moraine, and rock fracture zones.[10]

Geotechnical centrifuge modeling is another method of testing physical-scale models of geotechnical problems. The use of a centrifuge enhances the similarity of the scale model tests involving soil because soil's strength and stiffness are susceptible to the confining pressure. The centrifugal acceleration allows a researcher to obtain large (prototype-scale) stresses in small physical models.

Foundation design

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Main article: Foundation (engineering)

The foundation of a structure's infrastructure transmits loads from the structure to the earth. Geotechnical engineers design foundations based on the load characteristics of the structure and the properties of the soils and bedrock at the site. Generally, geotechnical engineers first estimate the magnitude and location of loads to be supported before developing an investigation plan to explore the subsurface and determine the necessary soil parameters through field and lab testing. Following this, they may begin the design of an engineering foundation. The primary considerations for a geotechnical engineer in foundation design are bearing capacity, settlement, and ground movement beneath the foundations.[11]

Earthworks

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A compactor/roller operated by U.S. Navy Seabees
See also: Earthworks (engineering)

Geotechnical engineers are also involved in the planning and execution of earthworks, which include ground improvement,[11] slope stabilization, and slope stability analysis.

Ground improvement

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Various geotechnical engineering methods can be used for ground improvement, including reinforcement geosynthetics such as geocells and geogrids, which disperse loads over a larger area, increasing the soil's load-bearing capacity. Through these methods, geotechnical engineers can reduce direct and long-term costs.[12]

Slope stabilization

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Simple slope slip section.
Main article: Slope stability

Geotechnical engineers can analyze and improve slope stability using engineering methods. Slope stability is determined by the balance of shear stress and shear strength. A previously stable slope may be initially affected by various factors, making it unstable. Nonetheless, geotechnical engineers can design and implement engineered slopes to increase stability.

Slope stability analysis
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Main article: Slope stability analysis

Stability analysis is needed to design engineered slopes and estimate the risk of slope failure in natural or designed slopes by determining the conditions under which the topmost mass of soil will slip relative to the base of soil and lead to slope failure.[13] If the interface between the mass and the base of a slope has a complex geometry, slope stability analysis is difficult and numerical solution methods are required. Typically, the interface's exact geometry is unknown, and a simplified interface geometry is assumed. Finite slopes require three-dimensional models to be analyzed, so most slopes are analyzed assuming that they are infinitely wide and can be represented by two-dimensional models.

Sub-disciplines

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Geosynthetics

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Main article: Geosynthetics
A collage of geosynthetic products.

Geosynthetics are a type of plastic polymer products used in geotechnical engineering that improve engineering performance while reducing costs. This includes geotextiles, geogrids, geomembranes, geocells, and geocomposites. The synthetic nature of the products make them suitable for use in the ground where high levels of durability are required. Their main functions include drainage, filtration, reinforcement, separation, and containment.

Geosynthetics are available in a wide range of forms and materials, each to suit a slightly different end-use, although they are frequently used together. Some reinforcement geosynthetics, such as geogrids and more recently, cellular confinement systems, have shown to improve bearing capacity, modulus factors and soil stiffness and strength.[14] These products have a wide range of applications and are currently used in many civil and geotechnical engineering applications including roads, airfields, railroads, embankments, piled embankments, retaining structures, reservoirs, canals, dams, landfills, bank protection and coastal engineering.[15]

Offshore

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Main article: Offshore geotechnical engineering
Platforms offshore Mexico.

Offshore (or marine) geotechnical engineering is concerned with foundation design for human-made structures in the sea, away from the coastline (in opposition to onshore or nearshore engineering). Oil platforms, artificial islands and submarine pipelines are examples of such structures.[16]

There are a number of significant differences between onshore and offshore geotechnical engineering.[16][17] Notably, site investigation and ground improvement on the seabed are more expensive; the offshore structures are exposed to a wider range of geohazards; and the environmental and financial consequences are higher in case of failure. Offshore structures are exposed to various environmental loads, notably wind, waves and currents. These phenomena may affect the integrity or the serviceability of the structure and its foundation during its operational lifespan and need to be taken into account in offshore design.

In subsea geotechnical engineering, seabed materials are considered a two-phase material composed of rock or mineral particles and water.[18][19] Structures may be fixed in place in the seabed—as is the case for piers, jetties and fixed-bottom wind turbines—or may comprise a floating structure that remains roughly fixed relative to its geotechnical anchor point. Undersea mooring of human-engineered floating structures include a large number of offshore oil and gas platforms and, since 2008, a few floating wind turbines. Two common types of engineered design for anchoring floating structures include tension-leg and catenary loose mooring systems.[20]

Observational method

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First proposed by Karl Terzaghi and later discussed in a paper by Ralph B. Peck, the observational method is a managed process of construction control, monitoring, and review, which enables modifications to be incorporated during and after construction. The method aims to achieve a greater overall economy without compromising safety by creating designs based on the most probable conditions rather than the most unfavorable.[21] Using the observational method, gaps in available information are filled by measurements and investigation, which aid in assessing the behavior of the structure during construction, which in turn can be modified per the findings. The method was described by Peck as "learn-as-you-go".[22]

The observational method may be described as follows:[22]

  1. General exploration sufficient to establish the rough nature, pattern, and properties of deposits.
  2. Assessment of the most probable conditions and the most unfavorable conceivable deviations.
  3. Creating the design based on a working hypothesis of behavior anticipated under the most probable conditions.
  4. Selection of quantities to be observed as construction proceeds and calculating their anticipated values based on the working hypothesis under the most unfavorable conditions.
  5. Selection, in advance, of a course of action or design modification for every foreseeable significant deviation of the observational findings from those predicted.
  6. Measurement of quantities and evaluation of actual conditions.
  7. Design modification per actual conditions

The observational method is suitable for construction that has already begun when an unexpected development occurs or when a failure or accident looms or has already happened. It is unsuitable for projects whose design cannot be altered during construction.[22]

See also

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  • Civil engineering
  • Deep Foundations Institute
  • Earthquake engineering
  • Earth structure
  • Effective stress
  • Engineering geology
  • Geological Engineering
  • Geoprofessions
  • Hydrogeology
  • International Society for Soil Mechanics and Geotechnical Engineering
  • Karl von Terzaghi
  • Land reclamation
  • Landfill
  • Mechanically stabilized earth
  • Offshore geotechnical engineering
  • Rock mass classifications
  • Sediment control
  • Seismology
  • Soil mechanics
  • Soil physics
  • Soil science

 

Notes

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  1. ^ a b c d Das, Braja (2006). Principles of Geotechnical Engineering. Thomson Learning.
  2. ^ a b Budhu, Muni (2007). Soil Mechanics and Foundations. John Wiley & Sons, Inc. ISBN 978-0-471-43117-6.
  3. ^ a b Disturbed soil properties and geotechnical design, Schofield, Andrew N., Thomas Telford, 2006. ISBN 0-7277-2982-9
  4. ^ Guerriero V., Mazzoli S. (2021). "Theory of Effective Stress in Soil and Rock and Implications for Fracturing Processes: A Review". Geosciences. 11 (3): 119. Bibcode:2021Geosc..11..119G. doi:10.3390/geosciences11030119.
  5. ^ Soil Mechanics, Lambe, T.William and Whitman, Robert V., Massachusetts Institute of Technology, John Wiley & Sons., 1969. ISBN 0-471-51192-7
  6. ^ Soil Behavior and Critical State Soil Mechanics, Wood, David Muir, Cambridge University Press, 1990. ISBN 0-521-33782-8
  7. ^ Terzaghi, K., Peck, R.B. and Mesri, G. (1996), Soil Mechanics in Engineering Practice 3rd Ed., John Wiley & Sons, Inc. ISBN 0-471-08658-4
  8. ^ Holtz, R. and Kovacs, W. (1981), An Introduction to Geotechnical Engineering, Prentice-Hall, Inc. ISBN 0-13-484394-0
  9. ^ Deep Scan Tech (2023): Deep Scan Tech uncovers hidden structures at the site of Denmark's tallest building.
  10. ^ "Geofrost Coring". GEOFROST. Retrieved 20 November 2020.
  11. ^ a b Han, Jie (2015). Principles and Practice of Ground Improvement. Wiley. ISBN 9781118421307.
  12. ^ RAJU, V. R. (2010). Ground Improvement Technologies and Case Histories. Singapore: Research Publishing Services. p. 809. ISBN 978-981-08-3124-0. Ground Improvement – Principles And Applications In Asia.
  13. ^ Pariseau, William G. (2011). Design analysis in rock mechanics. CRC Press.
  14. ^ Hegde, A.M. and Palsule P.S. (2020), Performance of Geosynthetics Reinforced Subgrade Subjected to Repeated Vehicle Loads: Experimental and Numerical Studies. Front. Built Environ. 6:15. https://www.frontiersin.org/articles/10.3389/fbuil.2020.00015/full.
  15. ^ Koerner, Robert M. (2012). Designing with Geosynthetics (6th Edition, Vol. 1 ed.). Xlibris. ISBN 9781462882892.
  16. ^ a b Dean, E.T.R. (2010). Offshore Geotechnical Engineering – Principles and Practice. Thomas Telford, Reston, VA, 520 p.
  17. ^ Randolph, M. and Gourvenec, S., 2011. Offshore geotechnical engineering. Spon Press, N.Y., 550 p.
  18. ^ Das, B.M., 2010. Principles of geotechnical engineering. Cengage Learning, Stamford, 666 p.
  19. ^ Atkinson, J., 2007. The mechanics of soils and foundations. Taylor & Francis, N.Y., 442 p.
  20. ^ Floating Offshore Wind Turbines: Responses in a Sea state – Pareto Optimal Designs and Economic Assessment, P. Sclavounos et al., October 2007.
  21. ^ Nicholson, D, Tse, C and Penny, C. (1999). The Observational Method in ground engineering – principles and applications. Report 185, CIRIA, London.
  22. ^ a b c Peck, R.B (1969). Advantages and limitations of the observational method in applied soil mechanics, Geotechnique, 19, No. 1, pp. 171-187.

References

[edit]
  • Bates and Jackson, 1980, Glossary of Geology: American Geological Institute.
  • Krynine and Judd, 1957, Principles of Engineering Geology and Geotechnics: McGraw-Hill, New York.
  • Ventura, Pierfranco, 2019, Fondazioni, Volume 1, Modellazioni statiche e sismiche, Hoepli, Milano
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  • Worldwide Geotechnical Literature Database
 
 
 
 

 

A load-bearing wall or bearing wall is a wall that is an active structural element of a building, which holds the weight of the elements above it, by conducting its weight to a foundation structure below it.

Load-bearing walls are one of the earliest forms of construction. The development of the flying buttress in Gothic architecture allowed structures to maintain an open interior space, transferring more weight to the buttresses instead of to central bearing walls. In housing, load-bearing walls are most common in the light construction method known as "platform framing". In the birth of the skyscraper era, the concurrent rise of steel as a more suitable framing system first designed by William Le Baron Jenney, and the limitations of load-bearing construction in large buildings, led to a decline in the use of load-bearing walls in large-scale commercial structures.

Description

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A load-bearing wall or bearing wall is a wall that is an active structural element of a building — that is, it bears the weight of the elements above said wall, resting upon it by conducting its weight to a foundation structure.[1] The materials most often used to construct load-bearing walls in large buildings are concrete, block, or brick. By contrast, a curtain wall provides no significant structural support beyond what is necessary to bear its own materials or conduct such loads to a bearing wall.[2]

History

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Load-bearing walls are one of the earliest forms of construction.[3] The development of the flying buttress in Gothic architecture allowed structures to maintain an open interior space, transferring more weight to the buttresses instead of to central bearing walls. The Notre Dame Cathedral is an example of a load-bearing wall structure with flying buttresses.[4]

Application

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Depending on the type of building and the number of floors, load-bearing walls are gauged to the appropriate thickness to carry the weight above them. Without doing so, it is possible that an outer wall could become unstable if the load exceeds the strength of the material used, potentially leading to the collapse of the structure. The primary function of this wall is to enclose or divide space of the building to make it more functional and useful. It provides privacy, affords security, and gives protection against heat, cold, sun or rain.[5]

Housing

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In housing, load-bearing walls are most common in the light construction method known as "platform framing", and each load-bearing wall sits on a wall sill plate which is mated to the lowest base plate. The sills are bolted to the masonry or concrete foundation.[6]

A beam of PSL lumber installed to replace a load-bearing wall at the first floor of a three-story building.

The top plate or ceiling plate is the top of the wall, which sits just below the platform of the next floor (at the ceiling). The base plate or floor plate is the bottom attachment point for the wall studs. Using a top plate and a bottom plate, a wall can be constructed while it lies on its side, allowing for end-nailing of the studs between two plates, and then the finished wall can be tipped up vertically into place atop the wall sill; this not only improves accuracy and shortens construction time, but also produces a stronger wall.

Skyscrapers

[edit]
The Chicago Willis Tower uses a bundle of tube structures which, in turn, include numerous outer wall columns.

Due to the immense weight of skyscrapers, the base and walls of the lower floors must be extremely strong. Pilings are used to anchor the building to the bedrock underground. For example, the Burj Khalifa, the world's tallest building as well as the world's tallest structure, uses specially treated and mixed reinforced concrete. Over 45,000 cubic metres (59,000 cu yd) of concrete, weighing more than 110,000 t (120,000 short tons) were used to construct the concrete and steel foundation, which features 192 piles, with each pile being 1.5 m diameter × 43 m long (4.9 ft × 141 ft) and buried more than 50 m (160 ft) deep.[7]

See also

[edit]
  • Column – in most larger, multi-storey buildings, vertical loads are primarily borne by columns / pillars instead of structural walls
  • Tube frame structure – Some of the world's tallest skyscrapers use load-bearing outer frames – be it single tube (e.g. the old WTC Twin Towers), or bundled tube (e.g. the Willis Tower or the Burj Khalifa)

References

[edit]
  1. ^ "How to Identify a Load-Bearing Wall". Lifehacker. Retrieved 2020-06-26.
  2. ^ "Load-bearing wall". www.designingbuildings.co.uk. Retrieved 2020-06-26.
  3. ^ Montaner, Carme (2021-03-31). "8º Simposio Iberoamericano de Historia de la Cartografía. El mapa como elemento de conexión cultural entre América y Europa. Barcelona, 21 y 22 de octubre del 2020". Investigaciones Geográficas (104). doi:10.14350/rig.60378. ISSN 2448-7279. S2CID 233611245.
  4. ^ Mendes, Gilmar de Melo (2012). El equilibrio de la arquitectura organizativa desde el enfoque de agencia: estudio de un caso (Thesis). Universidad de Valladolid. doi:10.35376/10324/921.
  5. ^ "7 FUNCTIONAL REQUIREMENTS A BUILDING WALL SHOULD SATISFY". CivilBlog.Org. 2015-07-08. Retrieved 2020-05-31.
  6. ^ "What is Platform Framing? (with pictures)". wiseGEEK. Retrieved 2020-06-26.
  7. ^ "Burj Khalifa, Dubai | 182168". Emporis. Archived from the original on August 5, 2011. Retrieved 2018-09-17.
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Reviews for

Jeffery James

(5)

Very happy with my experience. They were prompt and followed through, and very helpful in fixing the crack in my foundation.

Sarah McNeily

(5)

USS was excellent. They are honest, straightforward, trustworthy, and conscientious. They thoughtfully removed the flowers and flower bulbs to dig where they needed in the yard, replanted said flowers and spread the extra dirt to fill in an area of the yard. We've had other services from different companies and our yard was really a mess after. They kept the job site meticulously clean. The crew was on time and friendly. I'd recommend them any day! Thanks to Jessie and crew.

Jim de Leon

(5)

It was a pleasure to work with Rick and his crew. From the beginning, Rick listened to my concerns and what I wished to accomplish. Out of the 6 contractors that quoted the project, Rick seemed the MOST willing to accommodate my wishes. His pricing was definitely more than fair as well. I had 10 push piers installed to stabilize and lift an addition of my house. The project commenced at the date that Rick had disclosed initially and it was completed within the same time period expected (based on Rick's original assessment). The crew was well informed, courteous, and hard working. They were not loud (even while equipment was being utilized) and were well spoken. My neighbors were very impressed on how polite they were when they entered / exited my property (saying hello or good morning each day when they crossed paths). You can tell they care about the customer concerns. They ensured that the property would be put back as clean as possible by placing MANY sheets of plywood down prior to excavating. They compacted the dirt back in the holes extremely well to avoid large stock piles of soils. All the while, the main office was calling me to discuss updates and expectations of completion. They provided waivers of lien, certificates of insurance, properly acquired permits, and JULIE locates. From a construction background, I can tell you that I did not see any flaws in the way they operated and this an extremely professional company. The pictures attached show the push piers added to the foundation (pictures 1, 2 & 3), the amount of excavation (picture 4), and the restoration after dirt was placed back in the pits and compacted (pictures 5, 6 & 7). Please notice that they also sealed two large cracks and steel plated these cracks from expanding further (which you can see under my sliding glass door). I, as well as my wife, are extremely happy that we chose United Structural Systems for our contractor. I would happily tell any of my friends and family to use this contractor should the opportunity arise!

Chris Abplanalp

(5)

USS did an amazing job on my underpinning on my house, they were also very courteous to the proximity of my property line next to my neighbor. They kept things in order with all the dirt/mud they had to excavate. They were done exactly in the timeframe they indicated, and the contract was very details oriented with drawings of what would be done. Only thing that would have been nice, is they left my concrete a little muddy with boot prints but again, all-in-all a great job

Dave Kari

(5)

What a fantastic experience! Owner Rick Thomas is a trustworthy professional. Nick and the crew are hard working, knowledgeable and experienced. I interviewed every company in the area, big and small. A homeowner never wants to hear that they have foundation issues. Out of every company, I trusted USS the most, and it paid off in the end. Highly recommend.

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