Examining Expansive Clay in Residential Areas

Examining Expansive Clay in Residential Areas

* Identifying signs of expansive clay damage in homes.


Okay, so you're looking at a house, maybe thinking of buying, or just trying to keep your own place in good shape. Expert contractors use specialized techniques to stabilize shifting foundations foundation repair service areas construction. And you're in an area known for expansive clay soil. That's soil that swells up like a sponge when it gets wet and shrinks back down like a prune when it dries out. Not ideal for foundations, right? So, what are the telltale signs that this soil is messing with your house?

Think of it like this: the ground is moving, and your house isn't designed to be a rubber band. Cracks are often the first giveaway. We're not talking hairline cracks that appear and disappear; we're talking about cracks that are wider than a credit card, especially stair-step cracks in brickwork or cracks that run diagonally across walls. They're usually wider at the top than the bottom if the ground is settling unevenly.

Another clue is doors and windows that stick. Suddenly, that front door that used to swing open with ease needs a good shove. Windows become difficult to open and close. This is because the frame has been warped by the shifting foundation. Look for gaps around door and window frames too, or places where trim has separated from the wall.

Inside, you might notice sloping floors. A marble will roll towards one side of the room. Or maybe you see cracks appearing in the drywall, especially around door and window frames. Wallpaper might wrinkle or tear for no obvious reason.

Outside, check the foundation itself. Are there cracks visible? Is the foundation bowing inwards or outwards? Look at the landscaping around the foundation. Is the soil pulling away from the foundation? Are there large tree roots growing close to the house? Trees can exacerbate the problem by drawing moisture from the soil, leading to even more shrinking and swelling.

Ultimately, if you see these signs, it's time to call in a professional. A structural engineer or a geotechnical engineer can properly assess the damage and recommend solutions, which might range from drainage improvements to more extensive foundation repairs. It's better to catch these problems early before they turn into major headaches (and wallet-emptiers!). Ignoring them won't make them go away; expansive clay is a patient enemy.

* Common foundation problems caused by expansive clay soil.


Expansive clay soil: it's the silent nemesis lurking beneath many homes, particularly in certain regions. You might not see it, but it's wreaking havoc with your foundation. So, what are the common foundation problems that this pesky soil causes? Well, think of it like this: expansive clay is thirsty. When it's dry, it shrinks, pulling away from your foundation. Then, when it rains, it soaks up water like a sponge and expands. This constant cycle of shrinking and swelling puts immense pressure on your foundation.

One of the most common problems is cracking. You might start seeing hairline cracks in your foundation walls, floors, or even interior walls and ceilings. These cracks aren't always a sign of impending doom, but they definitely warrant investigation. Another issue is sticking doors and windows. As the foundation shifts, door and window frames can become misaligned, making them difficult to open and close. You might also notice sloping floors. This is a more serious sign of foundation movement and can be quite noticeable. Uneven surfaces and dips in your floors are telltale signs. Finally, water damage is a big concern. Cracks in the foundation can allow water to seep into your basement or crawlspace, leading to mold growth and structural damage. Essentially, expansive clay soil creates a constant tug-of-war with your foundation, and unfortunately, your foundation often loses. Addressing these problems early is key to preventing more significant and costly repairs down the road.

* Preventative measures homeowners can take to mitigate risks.


Okay, so you're dealing with expansive clay under your house. No fun, right? It's like living on a giant, slow-motion breathing monster. The good news is, you're not powerless. There are things you, as a homeowner, can do to fight back and minimize the potential damage. Think of it as preventative medicine for your house.

First, water is the enemy. Or, rather, *uneven* water is the enemy. Expansive clay swells when it's wet and shrinks when it's dry. This constant cycle is what causes the shifting and cracking. So, the goal is to keep the moisture levels around your foundation as consistent as possible. This means proper drainage is crucial. Make sure your gutters are clean and that downspouts are directing water *away* from the foundation, not pooling next to it. The further away, the better. Consider extending them if necessary.

Next, think about landscaping. Trees are beautiful, but their roots can suck moisture out of the soil, causing it to shrink. Plant trees far enough away from your foundation to minimize this effect. Also, be mindful of flowerbeds and shrubs. Consistent watering near the foundation, while good for the plants, can lead to uneven moisture levels in the soil. Consider using soaker hoses or drip irrigation systems to deliver water directly to the plants' roots, rather than saturating the surrounding soil.

Another often overlooked area is plumbing. Leaks, even small ones, can saturate the soil around your foundation. Regularly check your pipes, faucets, and sprinkler systems for any signs of leaks and repair them promptly. A little bit of vigilance can save you a whole lot of trouble down the road.

Finally, consider a professional assessment. A structural engineer or geotechnical expert can evaluate your specific situation and recommend tailored solutions. They might suggest things like installing root barriers, adding soil amendments, or even more extensive foundation repairs. While these options can be costly, they can be worth it in the long run to protect your investment.

Basically, it's all about managing the moisture around your foundation. Think consistent, think drainage, think early detection, and think professional help when needed. It's a battle, but one you can definitely win with a proactive approach.

* Foundation repair methods suited for expansive clay conditions.


Okay, so you're dealing with expansive clay soil around your house, huh? That's a tricky situation, because that stuff can really wreak havoc on your foundation. It's like it's got a mind of its own, swelling up when it's wet and shrinking back when it's dry. All that movement puts a ton of stress on your concrete. Now, when it comes to fixing a foundation damaged by expansive clay, you can't just use a one-size-fits-all approach. You've got to think about the specific problems you're seeing and then pick the right tool for the job.

One common method is underpinning. Think of it like giving your foundation some extra legs to stand on. You basically dig down and extend the footing deeper into the ground, ideally below the active clay zone. You can do this with concrete piers, steel piers, or even helical piers that screw into the ground. It's a pretty involved process, but it can really stabilize things.

Another option is soil modification. This is all about changing the properties of the clay itself. You might add lime or another stabilizing agent to the soil to reduce its swelling and shrinking potential. It's like giving the clay a chill pill, so it doesn't get so worked up with moisture changes. Sometimes, you can also improve drainage around your foundation to keep the soil moisture levels more consistent. Gutters that actually direct water away from the house are surprisingly helpful.

Then there's concrete replacement. If sections are severely cracked or failing, you might need to tear out the damaged parts and pour new concrete. This is often done in conjunction with other methods, like underpinning, to make sure the problem doesn't just come back again.

Ultimately, the best approach depends on a bunch of factors: the severity of the damage, the type of clay, and your budget. It's always a good idea to get a professional assessment from a qualified foundation repair contractor. They can take a look at your situation and give you a recommendation that's tailored to your specific needs. Don't just jump into the first fix you hear about – do your homework, and get a solid plan in place. Dealing with expansive clay is a long game, so you want to make sure you're making smart, sustainable choices.

* The role of professional foundation repair services.


Do not include any references.

Okay, so you're living in an area riddled with expansive clay. Maybe you've noticed a few cracks in your walls, doors sticking, or even a slight slope in your floors. It's unsettling, right? That's where professional foundation repair services come into play. They're not just guys with shovels; they're problem-solvers, diagnosticians, and ultimately, your home's best friend when dealing with the sneaky, destructive nature of expansive clay.

Think of them as doctors for your house. They start with a thorough examination, looking for the telltale signs – the patterns of cracking, the way the foundation is reacting to moisture changes. They'll use specialized equipment to assess the extent of the damage and, crucially, to understand the soil conditions beneath your home. This isn't a one-size-fits-all situation. Expansive clay behaves differently depending on the climate, the drainage, and even the vegetation around your property.

Based on their assessment, they'll recommend a tailored solution. This might involve installing piers to stabilize the foundation, improving drainage to control moisture levels, or even implementing a combination of techniques. The goal isn't just to patch things up; it's to address the root cause of the problem and prevent further damage down the road.

Trying to DIY foundation repair when you're dealing with expansive clay is usually a recipe for disaster. You might temporarily mask the symptoms, but you're unlikely to fix the underlying issue. Professional services bring the expertise, the specialized equipment, and the long-term perspective needed to safeguard your home against the relentless forces of expansive clay. They offer peace of mind, knowing that your foundation – the very bedrock of your home – is in good hands.

* Cost considerations for expansive clay related repairs.


Okay, so you've got expansive clay under your house. Not fun. Let's talk about the wallet-emptying potential of fixing problems that sneaky stuff causes. When it comes to dealing with expansive clay and residential areas, the price tag can be a real gut punch. It's not just a matter of slapping on some spackle and calling it day. Oh no, we're talking about potentially significant structural repairs, and those come with a hefty price.

First off, figuring out the extent of the damage is going to cost you. You need a good geotechnical engineer to assess the soil conditions, determine the moisture content, and understand how much it's moving. That's money right out of the gate. They'll give you a report, which is crucial, but it isn't free.

Then comes the repair itself. The cheapest "fix" might be superficial – cosmetic repairs like patching cracks in walls. But that's just putting lipstick on a pig. The underlying problem is still there, and the cracks will likely return, costing you more in the long run.

More substantial solutions involve things like soil stabilization, which can mean injecting chemicals to reduce the clay's swelling potential, or installing drainage systems to control moisture levels. Underpinning, where concrete piers are installed to support the foundation, is another common (and expensive) option. We're talking tens of thousands of dollars here, easily.

The cost varies wildly depending on the severity of the problem, the size of your house, and the type of repair needed. Access to the foundation also plays a big role. If it's difficult to get equipment in, labor costs go up. And don't forget permits! Local building codes often require permits for major foundation work, adding another layer of expense.

Beyond the immediate repair costs, consider the potential for indirect expenses. You might need to move out of your house while the work is being done, incurring relocation costs. Landscaping that's damaged during the repair process will need to be replaced. And then there's the potential impact on your property value. While a properly repaired foundation can actually *increase* value, a history of foundation problems, even if fully addressed, can sometimes raise eyebrows with potential buyers.

Basically, dealing with expansive clay is a game of risk management. Ignoring the problem won't make it go away; it'll just make it worse (and more expensive) down the line. Getting a thorough assessment and exploring all your repair options, with a clear understanding of the costs involved, is the only way to protect your home and your bank account. It's a tough situation, but knowledge is power, and a realistic budget is your best weapon.



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Strong Foundations, Strong Homes


 

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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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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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

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.

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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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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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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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

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  • 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 mobile home being repaired in Oklahoma
A person making these repairs to a house after a flood

Home repair involves the diagnosis and resolution of problems in a home, and is related to home maintenance to avoid such problems. Many types of repairs are "do it yourself" (DIY) projects, while others may be so complicated, time-consuming or risky as to require the assistance of a qualified handyperson, property manager, contractor/builder, or other professionals.

Home repair is not the same as renovation, although many improvements can result from repairs or maintenance. Often the costs of larger repairs will justify the alternative of investment in full-scale improvements. It may make just as much sense to upgrade a home system (with an improved one) as to repair it or incur ever-more-frequent and expensive maintenance for an inefficient, obsolete or dying system.

Worn, consumed, dull, dirty, clogged

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Repairs often mean simple replacement of worn or used components intended to be periodically renewed by a home-owner, such as burnt out light bulbs, worn out batteries, or overfilled vacuum cleaner bags. Another class of home repairs relates to restoring something to a useful condition, such as sharpening tools or utensils, replacing leaky faucet washers, cleaning out plumbing traps, rain gutters. Because of the required precision, specialized tools, or hazards, some of these are best left to experts such as a plumber. One emergency repair that may be necessary in this area is overflowing toilets. Most of them have a shut-off valve on a pipe beneath or behind them so that the water supply can be turned off while repairs are made, either by removing a clog or repairing a broken mechanism.

Broken or damaged

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Perhaps the most perplexing repairs facing a home-owner are broken or damaged things. In today's era of built-in obsolescence for many products, it is often more convenient to replace something rather than attempt to repair it. A repair person is faced with the tasks of accurately identifying the problem, then finding the materials, supplies, tools and skills necessary to sufficiently effect the repair. Some things, such as broken windows, appliances or furniture can be carried to a repair shop, but there are many repairs that can be performed easily enough, such as patching holes in plaster and drywall, cleaning stains, repairing cracked windows and their screens, or replacing a broken electrical switch or outlet. Other repairs may have some urgency, such as broken water pipes, broken doors, latches or windows, or a leaky roof or water tank, and this factor can certainly justify calling for professional help. A home handyperson may become adept at dealing with such immediate repairs, to avoid further damage or loss, until a professional can be summoned.

Emergency repairs

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Emergencies can happen at any time, so it is important to know how to quickly and efficiently fix the problem. From natural disasters, power loss, appliance failure and no water, emergency repairs tend to be one of the most important repairs to be comfortable and confident with. In most cases, the repairs are DIY or fixable with whatever is around the house. Common repairs would be fixing a leak, broken window, flooding, frozen pipes or clogged toilet. Each problem can have a relatively simple fix, a leaky roof and broken window can be patched, a flood can be pumped out, pipes can be thawed and repaired and toilets can be unclogged with a chemical. For the most part, emergency repairs are not permanent. They are what you can do fast to stop the problem then have a professional come in to permanently fix it.[1] Flooding as a result of frozen pipes, clogged toilets or a leaky roof can result in very costly water damage repairs and even potential health issues resulting from mold growth if not addressed in a timely manner.

Maintenance

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Periodic maintenance also falls under the general class of home repairs. These are inspections, adjustments, cleaning, or replacements that should be done regularly to ensure proper functioning of all the systems in a house, and to avoid costly emergencies. Examples include annual testing and adjustment of alarm systems, central heating or cooling systems (electrodes, thermocouples, and fuel filters), replacement of water treatment components or air-handling filters, purging of heating radiators and water tanks, defrosting a freezer, vacuum refrigerator coils, refilling dry floor-drain traps with water, cleaning out rain gutters, down spouts and drains, touching up worn house paint and weather seals, and cleaning accumulated creosote out of chimney flues, which may be best left to a chimney sweep.

Examples of less frequent home maintenance that should be regularly forecast and budgeted include repainting or staining outdoor wood or metal, repainting masonry, waterproofing masonry, cleaning out septic systems, replacing sacrificial electrodes in water heaters, replacing old washing machine hoses (preferably with stainless steel hoses less likely to burst and cause a flood), and other home improvements such as replacement of obsolete or ageing systems with limited useful lifetimes (water heaters, wood stoves, pumps, and asphaltic or wooden roof shingles and siding.

Often on the bottom of people's to-do list is home maintenance chores, such as landscaping, window and gutter cleaning, power washing the siding and hard-scape, etc. However, these maintenance chores pay for themselves over time. Often, injury could occur when operating heavy machinery or when climbing on ladders or roofs around your home, so if an individual is not in the proper physical condition to accomplish these chores, then they should consult a professional. Lack of maintenance will cost more due to higher costs associated with repairs or replacements to be made later. It requires discipline and learning aptitude to repair and maintain the home in good condition, but it is a satisfying experience to perform even seemingly minor repairs.

Good operations

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Another related issue for avoiding costly repairs (or disasters) is the proper operation of a home, including systems and appliances, in a way that prevents damage or prolongs their usefulness. For example, at higher latitudes, even a clean rain gutter can suddenly build up an ice dam in winter, forcing melt water into unprotected roofing, resulting in leaks or even flooding inside walls or rooms. This can be prevented by installing moisture barrier beneath the roofing tiles. A wary home-owner should be alert to the conditions that can result in larger problems and take remedial action before damage or injury occurs. It may be easier to tack down a bit of worn carpet than repair a large patch damaged by prolonged misuse. Another example is to seek out the source of unusual noises or smells when mechanical, electrical or plumbing systems are operating—sometimes they indicate incipient problems. One should avoid overloading or otherwise misusing systems, and a recurring overload may indicate time for an upgrade.

Water infiltration is one of the most insidious sources of home damage. Small leaks can lead to water stains, and rotting wood. Soft, rotten wood is an inviting target for termites and other wood-damaging insects. Left unattended, a small leak can lead to significant structural damage, necessitating the replacement of beams and framing.

With a useful selection of tools, typical materials and supplies on hand, and some home repair information or experience, a home-owner or handyperson should be able to carry out a large number of DIY home repairs and identify those that will need the specialized attention of others.

Remediation of environmental problems

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When a home is sold, inspections are performed that may reveal environmental hazards such as radon gas in the basement or water supply or friable asbestos materials (both of which can cause lung cancer), peeling or disturbed lead paint (a risk to children and pregnant women), in-ground heating oil tanks that may contaminate ground water, or mold that can cause problems for those with asthma or allergies. Typically the buyer or mortgage lender will require these conditions to be repaired before allowing the purchase to close. An entire industry of environmental remediation contractors has developed to help home owners resolve these types of problems.

See also

[edit]
  • Electrical wiring
  • Handyperson
  • Housekeeping
  • Home improvement
  • Home wiring
  • HVAC
  • Maintenance, repair, and operations
  • Plumbing
  • Right to repair
  • Smoke alarm
  • Winterization

References

[edit]
  1. ^ Reader's Digest New Complete Do-it-yourself Manual. Montreal, Canada: Reader's Digest Association. 1991. pp. 9–13. ISBN 9780888501783. OCLC 1008853527.

 

In geotechnical engineering, soil compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other liquid) being displaced from between the soil grains, then consolidation, not compaction, has occurred. Normally, compaction is the result of heavy machinery compressing the soil, but it can also occur due to the passage of, for example, animal feet.

In soil science and agronomy, soil compaction is usually a combination of both engineering compaction and consolidation, so may occur due to a lack of water in the soil, the applied stress being internal suction due to water evaporation[1] as well as due to passage of animal feet. Affected soils become less able to absorb rainfall, thus increasing runoff and erosion. Plants have difficulty in compacted soil because the mineral grains are pressed together, leaving little space for air and water, which are essential for root growth. Burrowing animals also find it a hostile environment, because the denser soil is more difficult to penetrate. The ability of a soil to recover from this type of compaction depends on climate, mineralogy and fauna. Soils with high shrink–swell capacity, such as vertisols, recover quickly from compaction where moisture conditions are variable (dry spells shrink the soil, causing it to crack). But clays such as kaolinite, which do not crack as they dry, cannot recover from compaction on their own unless they host ground-dwelling animals such as earthworms—the Cecil soil series is an example.

Before soils can be compacted in the field, some laboratory tests are required to determine their engineering properties. Among various properties, the maximum dry density and the optimum moisture content are vital and specify the required density to be compacted in the field.[2]

A 10 tonne excavator is here equipped with a narrow sheepsfoot roller to compact the fill over newly placed sewer pipe, forming a stable support for a new road surface.
A compactor/roller fitted with a sheepsfoot drum, operated by U.S. Navy Seabees
Vibrating roller with plain drum as used for compacting asphalt and granular soils
Vibratory rammer in action

In construction

[edit]

Soil compaction is a vital part of the construction process. It is used for support of structural entities such as building foundations, roadways, walkways, and earth retaining structures to name a few. For a given soil type certain properties may deem it more or less desirable to perform adequately for a particular circumstance. In general, the preselected soil should have adequate strength, be relatively incompressible so that future settlement is not significant, be stable against volume change as water content or other factors vary, be durable and safe against deterioration, and possess proper permeability.[3]

When an area is to be filled or backfilled the soil is placed in layers called lifts. The ability of the first fill layers to be properly compacted will depend on the condition of the natural material being covered. If unsuitable material is left in place and backfilled, it may compress over a long period under the weight of the earth fill, causing settlement cracks in the fill or in any structure supported by the fill.[4] In order to determine if the natural soil will support the first fill layers, an area can be proofrolled. Proofrolling consists of utilizing a piece of heavy construction equipment to roll across the fill site and watching for deflections to be revealed. These areas will be indicated by the development of rutting, pumping, or ground weaving.[5]

To ensure adequate soil compaction is achieved, project specifications will indicate the required soil density or degree of compaction that must be achieved. These specifications are generally recommended by a geotechnical engineer in a geotechnical engineering report.

The soil type—that is, grain-size distributions, shape of the soil grains, specific gravity of soil solids, and amount and type of clay minerals, present—has a great influence on the maximum dry unit weight and optimum moisture content.[6] It also has a great influence on how the materials should be compacted in given situations. Compaction is accomplished by use of heavy equipment. In sands and gravels, the equipment usually vibrates, to cause re-orientation of the soil particles into a denser configuration. In silts and clays, a sheepsfoot roller is frequently used, to create small zones of intense shearing, which drives air out of the soil.

Determination of adequate compaction is done by determining the in-situ density of the soil and comparing it to the maximum density determined by a laboratory test. The most commonly used laboratory test is called the Proctor compaction test and there are two different methods in obtaining the maximum density. They are the standard Proctor and modified Proctor tests; the modified Proctor is more commonly used. For small dams, the standard Proctor may still be the reference.[5]

While soil under structures and pavements needs to be compacted, it is important after construction to decompact areas to be landscaped so that vegetation can grow.

Compaction methods

[edit]

There are several means of achieving compaction of a material. Some are more appropriate for soil compaction than others, while some techniques are only suitable for particular soils or soils in particular conditions. Some are more suited to compaction of non-soil materials such as asphalt. Generally, those that can apply significant amounts of shear as well as compressive stress, are most effective.

The available techniques can be classified as:

  1. Static – a large stress is slowly applied to the soil and then released.
  2. Impact – the stress is applied by dropping a large mass onto the surface of the soil.
  3. Vibrating – a stress is applied repeatedly and rapidly via a mechanically driven plate or hammer. Often combined with rolling compaction (see below).
  4. Gyrating – a static stress is applied and maintained in one direction while the soil is a subjected to a gyratory motion about the axis of static loading. Limited to laboratory applications.
  5. Rolling – a heavy cylinder is rolled over the surface of the soil. Commonly used on sports pitches. Roller-compactors are often fitted with vibratory devices to enhance their effectiveness.
  6. Kneading – shear is applied by alternating movement in adjacent positions. An example, combined with rolling compaction, is the 'sheepsfoot' roller used in waste compaction at landfills.

The construction plant available to achieve compaction is extremely varied and is described elsewhere.

Test methods in laboratory

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Soil compactors are used to perform test methods which cover laboratory compaction methods used to determine the relationship between molding water content and dry unit weight of soils. Soil placed as engineering fill is compacted to a dense state to obtain satisfactory engineering properties such as, shear strength, compressibility, or permeability. In addition, foundation soils are often compacted to improve their engineering properties. Laboratory compaction tests provide the basis for determining the percent compaction and molding water content needed to achieve the required engineering properties, and for controlling construction to assure that the required compaction and water contents are achieved. Test methods such as EN 13286-2, EN 13286-47, ASTM D698, ASTM D1557, AASHTO T99, AASHTO T180, AASHTO T193, BS 1377:4 provide soil compaction testing procedures.[7]

See also

[edit]
  • Soil compaction (agriculture)
  • Soil degradation
  • Compactor
  • Earthwork
  • Soil structure
  • Aeration
  • Shear strength (soil)
Multiquip RX1575 Rammax Sheepsfoot Trench Compaction Roller on the jobsite in San Diego, California

References

[edit]
  1. ^ Soil compaction due to lack of water in soil
  2. ^ Jia, Xiaoyang; Hu, Wei; Polaczyk, Pawel; Gong, Hongren; Huang, Baoshan (2019). "Comparative Evaluation of Compacting Process for Base Materials using Lab Compaction Methods". Transportation Research Record: Journal of the Transportation Research Board. 2673 (4): 558–567. doi:10.1177/0361198119837953. ISSN 0361-1981.
  3. ^ McCarthy, David F. (2007). Essentials of Soil Mechanics and Foundations. Upper Saddle River, NJ: Pearson Prentice Hall. p. 595. ISBN 978-0-13-114560-3.
  4. ^ McCarthy, David F. (2007). Essentials of Soil Mechanics and Foundations. Upper Saddle River, NJ: Pearson Prentice Hall. pp. 601–602. ISBN 978-0-13-114560-3.
  5. ^ a b McCarthy, David F. (2007). Essentials of Soil Mechanics and Foundations. Upper Saddle River, NJ: Pearson Prentice Hall. p. 602. ISBN 978-0-13-114560-3.
  6. ^ Das, Braja M. (2002). Principles of Geotechnical Engineering. Pacific Grove, CA: Brooks/Cole. p. 105. ISBN 0-534-38742-X.
  7. ^ "Automatic Soil Compactor". cooper.co.uk. Cooper Research Technology. Archived from the original on 27 August 2014. Retrieved 8 September 2014.

 

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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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